The Thomist 86 (2022): 1-51

ENERGY AND FORM
THOMAS MCLAUGHLIN
St. John Vianney Theological Seminary
Denver, Colorado

I

N DISCUSSING EVOLUTION, St. John Paul II wrote that
“the elaboration of a theory like that of evolution, while
obeying the requirement of homogeneity with observational
data, incorporates certain notions from the philosophy of nature.”1 John Paul II then went on to speak of evolution in the
plural, of “theories of evolution.” The different theories are
distinguished not only by positing different mechanisms of
evolution but also by incorporating different philosophies.2
Theories such as evolution must draw upon some principles of
natural philosophy, and different philosophies make for different evolutionary theories. Since incorporating some natural
philosophy is necessary not only for evolution but also for
scientific theories more generally, we can also speak of other
scientific theories in the plural since they are or could be diversified by the different philosophies that they incorporate or
could incorporate. Thus, the notion of energy, one of the most
important physical principles in modern science, could be formulated through incorporating different philosophies, and we
could speak of theories of energy, depending upon the different
natural philosophies that such theories of energy draw upon.
I propose an Aristotelian/Thomistic theory of energy, a
theory of energy that would incorporate general principles of
Aristotelian/Thomistic natural philosophy to better understand
1
John Paul II, “Message du Saint-Père Jean Paul II aux membres de l’assemblée
plénière de l’académie pontificale des sciences” (1996), no. 4 (https://www.vatican.va/
content/john-paul-ii/fr/messages/pont_messages/1996/documents/hf_jp-ii_mes_
19961022_evoluzione.html); my translation.
2
Ibid.

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THOMAS MCLAUGHLIN

nature. It would involve a general philosophical framework or
lens in and through which energy and its corresponding notions
could be further understood and it would also offer a much
more highly specified Aristotelian or Thomistic way of understanding the natural world. The task of developing such a
theory of energy is made easier since some general principles of
Aristotelian/Thomistic natural philosophy are already, in a way,
part of the science of energy and are implicit within it.3 In a
previous article in this journal I argued that the scientific notion
of energy is a specific instance of the Aristotelian/Thomistic
principles of act and potency.4 In this article, I shall consider
“form.” I shall argue that “form” as it is used with respect to the
different forms of energy is a specific instance of form in the
Aristotelian or Thomistic sense.
The term “form” has different and complex uses that present
some complications that are relevant to the discussion of the
forms of energy. These will be addressed in the course of the
argument. At the moment, I may indicate that by “specific
instances of form in the Aristotelian or Thomistic sense” I mean
first that the forms of energy are different kinds or species of
energy, and second that they are accidental forms by which
things have these kinds and quantities of energy. The former
usage is quite explicit in the sciences while the latter is not. An
3
According to William Rankine, who introduced the term “potential energy” into
physics, “The step which I took in 1853, of applying the distinction between ‘Actual
Energy’ and ‘Potential Energy,’ not to motion and mechanical power alone, but to all kinds
of physical phenomena, was suggested to me, I think, by Aristotle’s use of the words
δύναμις and ενέργεια” (William Rankine, “On the History of Energetics,” The London,
Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 4th series, 28, no.
190 [1864]: 404). Rankine also asserts that the scientific meaning of “energy,” which
was first introduced by Thomas Young in 1807, harmonizes “perfectly with the
etymology of ενέργεια” (William Rankine, “On the Phrase ‘Potential Energy,’ and on
the Definitions of Physical Quantities” (1867) in Miscellaneous Scientific Papers, ed.
W. J. Millar [London: Charles Griffin and Co., 1881], 230).
4
Thomas McLaughlin, “Act, Potency, and Energy,” The Thomist 75 (2011): 207-43.
For a further development of this project that includes the Principle of Least Action and
final causality, see John Brungardt, “The Action and Power of the Universe, Pt. 1”
(https://johngbrungardt.com/2018/11/16/the-action-and-power-of-the-universe-2/) and
“The Action and Power of the Universe, Pt. 2” (https://johngbrungardt.com/2018/11/30/
the-principle-of-least-action-chile/) (accessed 1/28/2021).

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3

example may help. “Musical” is an accidental formal cause by
which a person is musical or is a musician as opposed to being a
painter, a dancer, or a sculptor. Thus, “musical” can mean
either the accidental formal cause or a kind of art or art form.
The two different meanings are closely related. Sometimes, we
distinguish them by inventing a word for the accidental formal
cause, such as “musicalness” or “musicality.” Similarly, “form of
energy” can, and usually does, mean a kind of energy, but it can
also mean or imply an accidental formal cause in a subject.
“Chemical energy” usually means a kind of energy but can also
mean or imply the accidental formal cause by which a subject,
such as coal, has chemical energy.
In arguing for my thesis, I shall focus on the Law of the
Conservation of Energy and the discussions on energy by
several physicists, especially Richard Feynman. I shall then
discuss the forms of energy with respect to order in nature and
the universe.
I. FORM, AND FEYNMAN ON ENERGY
I begin with the Law of the Conservation of Energy. The
Nobel-prize winning physicist Richard Feynman describes this
law as follows:
Energy has a large number of different forms, and there is a formula for each
one. These are: gravitational energy, kinetic energy, heat energy, elastic
energy, electrical energy, chemical energy, radiant energy, nuclear energy,
mass energy. If we total up the formulas for each of these contributions, it will
not change except for energy going in and out.5

Feynman lists the forms of energy at what might be called a
generic level. The forms of energy may also be considered more
specifically.6 Hybrid cars, for example, use two different forms

5
Richard P. Feynman, Robert B. Leighton, and Matthew Sands, The Feynman
Lectures on Physics (Reading, Mass.: Addison-Wesley Publishing Company, 1963),
vol. 1, chap. 4, p. 2.
6
“More precisely, there are as many kinds of energy as kinds of processes” (Mario
Bunge, “Energy: Between Physics and Metaphysics” in Scientific Realism, Selected

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THOMAS MCLAUGHLIN

of chemical energy: that of a battery and that of gasoline. ATP
(adenosine triphosphate) is an organic compound that provides
a fundamental form of chemical energy for living things. We
also speak of the energy of coal or dynamite or food, or of solar
panels. We speak of wind energy or the energy of a flowing
river or of a reservoir behind a dam, or of lightning, or of
steam. We may consider the binding energy of uranium or
helium atoms, or the binding energy of various oxygen or other
kinds of compounds. We also speak of particular things, such as
this thunderstorm, this hunk of coal, this light bulb, this orange,
this atom, this windmill, this magnet, this heater, or this x-ray as
having definite quantities of various forms of energy. Any
massive thing has a definite quantity of mass energy. A massless
particle of light, such as this photon, has a definite quantity of
radiant energy. Indeed, all known physical things have some
form or forms of energy. Thus, we look upon a world
composed of a multitude of things each possessing various
particularized forms of energy. This suggests an Aristotelian
view of the world as consisting of a multitude of diverse things
each possessing accidental and substantial forms.
We sometimes speak of different kinds or different species of
things as different forms of things. This is the primary way in
which scientists speak of the forms of energy. By the forms of
energy, they especially mean the different kinds of energy.
Aristotle and Aquinas also speak of “form” in this sense as
species.7 In regard to energy, “form” in this sense is an esEssays of Mario Bunge, ed. Martin Mahner [Amherst, N.Y.: Prometheus Books, 2001],
51).
7
“Species is compared to the individual, dog to this dog, as form to matter; and for
this reason, form is frequently taken as meaning the whole species or essence, that is, the
composite of matter and form. Form in this sense means that by which a thing is what it
is, dog, copper, man, etc. This use of the term ‘form’ to mean the whole species is a
legitimate and valuable one. It is an extremely useful definition in many ways even in
our own science of nature” (Vincent Edward Smith, The General Science of Nature
[Milwaukee: Bruce Publ. Co., 1958], 175). Smith cites De Pot., q. 9, a. 1; V Metaphys.,
lect. 2 (Maretti ed., 764); VII Metaphys., lect. 9 (Marietii ed., 1467-69); STh I, q. 85, a.
4, ad 4; II Phys., lect. 11 (St. Thomas Aquinas, Commentary on Aristotle’s Physics, trans.
Richard J. Blackwell, Richard J. Spath, and W. Edmund Thirlkel [Notre Dame, Ind.:
Dumb Ox Books, 1999], 4 and 8).

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pecially appropriate term. Part of what makes energy such a
difficult as well as such an encompassing and fundamental
physical notion are the wide-ranging differences in the kinds of
energy as well as their convertibility, combined with the
distinction of energy from force. The many different units in
which energy has been measured—joules, calories, barrels,
Btu’s, kilowatt-hours, and so forth—not only distinguish energy
from force but also reflect the diversity in the forms of energy
and the many different subject areas and researchers involved in
the discovery and development of the conservation of energy.
Even since Feynman wrote, a new form of energy, dark energy,
has been discovered. Many of these forms initially appear to be
unrelated. Mass, for instance, is not obviously energetic or
transformable. The term “form” has sufficient breadth to
encompass this diverse range of things. We especially speak of
kinds as forms when asking what kind of thing something is in
comparison to other related kinds. In ordinary usage, we speak
of diverse kinds of things that have some basic, broad
commonality as different in form, the form specifying the kind
of thing.8 We speak thus of different life forms or of different
forms of minerals.
“Form” also has a different but closely related meaning.
“Form,” according to Aquinas, is also the principle of the
species.9 It is that by which a thing is the kind of thing it is and
is distinguished from other kinds of things. In this sense, “form”
means formal cause.
The two senses of form are closely related and are often used
interchangeably, for we often identify or speak of something
through its principal part, and the formal cause is the primary
principle of the species. Similarly, a formal cause is inseparable
from its effect, and we sometimes speak of a cause by its effect.
Thus, to use “form” in one way implies the presence of form in
the other way. To say that the different forms of energy are
8

Richard J. Connell, Nature’s Causes (New York: Peter Lang, 1995), 78.
“Operation follows upon the form which is the principle of the species” (ScG II,
c. 75). All English quotations from Aquinas’s Summa contra gentiles II are from Thomas
Aquinas, Summa contra gentiles, book 2, trans. James F. Anderson (Notre Dame:
University of Notre Dame Press, 1991).
9

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THOMAS MCLAUGHLIN

different kinds of energy implies that the kinds have formal
causes that cause them to be the different kinds of energy that
they are.
Furthermore, not only does a diversity of species result from
a diversity of forms, but from these different forms different
operations follow.10 A thing acts according to its form because
everything acts inasmuch as it is in act and everything is in act
through its form.11 The conservation of energy and the diversity
of the forms of energy indicate this Aristotelian understanding of
form as the principle of the species and of operation. The Law
of the Conservation of Energy not only describes the interrelations of the different forms of energy but also distinguishes
them and emphasizes their differences while exhibiting a
profound unity among them. Each form of energy has its own
determinate character, formula, and pattern of activity that
distinguishes it from other forms of energy.12 A thing acts
according to the kind of energy it has, according to its form of
energy. We know what the different forms of energy do and
what they do reveals something of what they are. For example,
we are keenly aware of the very different and distinctive ways in
10
“Now, the mode of acting peculiar to each thing results from its form, which is the
source of action” (ScG III, c. 73). All English quotations from Aquinas’s Summa contra
gentiles III are from Thomas Aquinas, Summa contra gentiles, book 3, trans. Vernon J.
Bourke (Notre Dame: University of Notre Dame Press, 1991).
11
“Everything acts in accord with its form” (STh I, q. 4, a. 3). All English quotations
from Aquinas’s Summa theologiae are from The Basic Writings of St. Thomas Aquinas,
ed. Anton Pegis (New York: Random House, 1945). “Now, from the diversity of forms
by which the species of things are differentiated there also results a difference of
operations. For since everything acts insofar as it is actual (because things that are
potential are found by that very fact to be devoid of action), and since every being is
actual through its form, it is necessary for the operation of a thing to follow its form”
(ScG III, c. 97).
12
“The investigation of energy in physical systems is, to this day, an inquiry into its
forms. According to Maxwell, ‘in the study of any new phenomenon our first inquiry
must be, How can this phenomenon be explained as a transformation of energy? What
is the original form of energy? What is its final form? and What are the conditions of
the transformation?’” (Benedikt W. Harrer, “On the Origin of Energy: Metaphors and
Manifestations as Resources for Conceptualizing and Measuring the Invisible,
Imponderable,” American Journal of Physics 85 [2017]: 458). Harrer quotes from J. C.
Maxwell, “Herman Ludwig Ferdinand Helmholtz,” Nature 15 (1877): 390.

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7

which nuclear and solar energy and fossil fuels and gravitational
energy operate and do work. We often convert these forms of
energy into electrical energy or into heat, forms of energy that
are often more useful to us. Since, for Aristotle, the way something acts follows from the way it is, and the way something is
follows from its form, form for Aristotle is a cause, a formal
cause. This suggests that, since the various forms of energy characterize the way things are and the way they act, the forms of
energy are also formal causes that determine things to be such
as they are.
However, the forms of energy seem to be accidental even in
changes that are arguably substantial, for though some forms of
energy, such as mass, would seem to be essential for many kinds
of bodies, nevertheless they do not make a body be absolutely
but only make a body be such and so much. In this regard, the
forms of energy, considered as different kinds of energy, are not
like different life forms or the different forms of minerals, for
minerals and living things are substances or things. Like colors,
the forms of energy are different kinds of accidents. Further,
though an accident must be in a subject, an accident is not itself
composed of matter and form. The accident is a form, an accidental formal cause.13 Thus, since a form of energy, such as

13
“In the case of an accident of a composed substance, if we can speak of what is in
it, we must not think that it has a matter and a form; an accident has no intrinsic causes.
To speak of what is in it is to speak only of what the accident itself is, for the accident is
a form, a form such that matter is no part of what it is, a form such that (unlike a
substantial form) it does not come to be in matter as in a subject, a form such that it
comes to be in a complete substance as in a subject. The substance in which an accident
comes to be is related to that accident as matter is related to substantial form. Just as
matter must be such by its nature that it can acquire and maintain the substantial form
received in a change, so too the substance must be such by its nature that it can acquire
and maintain the accident received in a change. Thus, we can speak of a form and of a
matter both in the case of a substance and in the case of an accident, but it is only in the
case of a substance that both the matter and the form are intrinsic causes. In the case of
an accident the form can be said to be intrinsic to, though not an intrinsic cause of, the
accident in the sense that it is identical with the accident itself; the matter, however, is
an extrinsic cause, for the matter is the substance . . . in which the accident exists, and
apart from which the accident does not exist. Only that can be defined by intrinsic
causes which has them, and an accident does not have them (nor does a substantial

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chemical or mass energy, is an accident, it is an accidental form
since accidents are not composed. However, the definition of an
accident includes being in a subject. Thus, a form of energy is an
accident by which a subject has a kind of energy. Further, the
subject is the principle of individuation of an accident. To say,
then, that a piece of coal has various particularized forms of
energy is to say that a subject, namely, this piece of coal, has
these accidents, namely, the various accidental forms of energy
by which the coal has energy. Consequently, the form of energy
is itself not only a kind of energy but also is an accidental
formal cause in a subject. It modifies a subject and makes it to
be such.
In further explaining the Law of the Conservation of Energy,
Feynman writes,
It is not a description of a mechanism, or anything concrete; it is just a strange
fact that we can calculate some number and when we finish watching nature
go through her tricks and calculate the number again, it is the same. . . . Since
it is an abstract idea, we shall illustrate the meaning of it by an analogy.14

We shall return to the analogy and to Feynman’s claims that
energy and the Law of the Conservation of Energy are abstract
and mathematical. For now, I want to note that a change from
one form of energy to another or a change in the amount of a
form of energy is not a description of a mechanism. It is not a
specific type of process, such as a chemical reaction, that certain
things undergo. It is a change of the form of energy in which a
certain quantity is conserved. Similarly, just as the conservation
of energy is a general law but not a description of a mechanism,
for Aristotle and Aquinas, generation and corruption are not
mechanisms but are general descriptions of substantial and
accidental change in terms of form.15 Likewise, just as
form)” (Joseph Bobik, Aquinas On Being and Essence: A Translation and Interpretation
[Notre Dame: University of Notre Dame Press, 1991], 245-46).
14
Feynman, Feynman Lectures on Physics, vol. 1, chap. 4, p. 1. Feynman also says
that the conservation of energy “is a mathematical principle; it says that there is a
numerical quantity which does not change when something happens” (ibid.).
15
“Because generation is motion to form, there are two kinds of generation
corresponding to the two kinds of form. . . . There are two kinds of corruption opposed

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9

mechanisms are certainly involved in the physical processes to
which the Law of the Conservation of Energy applies, such as
photosynthesis or nuclear fusion, Aquinas thought that there
were mechanisms involved in the physical processes to which
generation and corruption applied, such as the combining of
elements in definite ratios to make a mineral.16 The Law of the
Conservation of Energy and Aquinas’s understanding of generation and corruption both treat change in terms of form, and
both abstract from the specific and detailed mechanisms involved in physical processes, although they also apply to the
mechanisms in such processes. The Law of the Conservation of
Energy, however, is also quantitative whereas Aquinas’s general
account of generation and corruption was not formulated
quantitatively.
In addition, Aristotle and Aquinas maintain that in all
generation and corruption, whether substantial or accidental,
forms are gained and lost or things are increased or decreased
according to their forms.17 Further, the gain of one form is
necessarily the loss of another and conversely:
The corruption of this is the generation of something else, and vice versa . . .
for although that which is corrupted becomes non-being, yet something else
remains, namely, that which has been generated. Accordingly matter cannot
remain without being subjected to some form. That is why, upon the
corruption of one thing, another is generated, and upon the generation of one
thing another is corrupted. Consequently, there is in generation and
corruption a certain cycle which gives it the aptitude to last forever.18
to these two kinds of generation” (De Princ. Natur., c. 1 [Joseph Bobik, Aquinas on
Matter and Form and the Elements: A Translation and Interpretation of the “De
Principiis Naturae” and the “De Mixtione Elementorum” of St. Thomas Aquinas (Notre
Dame, Ind.: University of Notre Dame Press, 1998), 8-9]).
16
See, for example, Aristotle, On Generation and Corruption II; Aristotle,
Meteorology; Albertus Magnus, Book of Minerals, trans. Dorothy Wyckoff (Oxford:
Clarendon Press, 1967).
17
“In order, therefore, that there be generation, three things are required: namely,
being in potency, which is matter; non-being in act, which is privation; and that through
which a thing comes to being in act, namely form” (De Princ. Natur. c. 1 [Bobik, trans.,
10]).
18
I Gen. et Corrup., lect. 7 (Thomas Aquinas, Commentary on Aristotle’s Generation
and Corruption, trans. Pierre Conway and R. F. Larcher [Columbus, Ohio: College of
St. Mary of the Springs, 1964], 57). Unpublished but circulated in photocopied form. I

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When something is destroyed, it is not annihilated so that
nothing at all remains. Its matter persists and something new
comes to be that has another form. A thing can lose the form by
which it exists or exists as such, “but at once its matter takes on
another form. There is always matter. And there is always form,
though not always the same form.”19 The reason for this is that
matter cannot be without form.
We see a parallel to this Aristotelian principle in the Law of
the Conservation of Energy. The conservation of energy is a law
to which there are no known exceptions and which governs all
known natural phenomena.20 Thus, all physical processes involve gaining and losing forms of energy, or increasing or
decreasing the quantity of a form of energy, or moving something having a form of energy to a different location. Heating
water on a stove increases and transfers its thermal energy.
Burning gasoline is a change from one kind of chemical energy
to another kind of chemical energy and to thermal and other
forms of energy as well. Adding mass increases a system’s
energy. Power plants involve changes in forms of energy, as

thank Fr. Stephen L. Brock for bringing this text to my attention in connection with the
Law of the Conservation of Energy.
19
Stephen L. Brock, “Aquinas’ Third Way of Proving a God: Logic or Love?”
(Cardinal Stafford Lecture given at St. John Vianney Theological Seminary, Denver,
Col., February 2015), 14.
20
“There is a fact, or if you wish, a law, governing all natural phenomena that are
known to date. There is no known exception to this law—it is exact so far as we know.
This law is called the conservation of energy” (Feynman, Feynman Lectures on Physics,
vol. 1, chap. 4, p. 1). However, some physicists maintain that energy is not conserved
for the universe taken as a whole. See, for example, Geraint F. Lewis and Luke A.
Barnes, The Fortunate Universe (Cambridge: Cambridge University Press, 2016),
193-95; Edward R. Harrison, “Mining Energy in an Expanding Universe,” The
Astrophysical Journal 446 (1995): 63-66; idem, Cosmology: The Science of the Universe,
2nd ed. (Cambridge: Cambridge University Press, 2000), 348-49; John Frederick
Hawley and Katherine A. Holcomb, Foundations of Modern Cosmology (Oxford:
Oxford University Press, 2005), 414-15. If indeed, energy is not conserved for the
universe as a whole, then one possible implication is that the laws of nature vary with
time. Another possible implication is that the physical universe is not a closed system.
See John Brungardt, “Is Aristotelian-Thomistic Natural Philosophy Still Relevant to
Cosmology?” Proceedings of the American Catholic Philosophical Association 93 (2019):
160.

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when a hydroelectric plant changes the gravitational energy of a
body of water to electrical energy.
Further, if the Law of the Conservation of Energy is a
genuine law, then the gain or loss of one form is necessarily the
loss or gain of another because any gain or loss must be
compensated for, so that the amount of energy remains the
same throughout some change.21 Since the quantity of energy
must remain constant, whenever a body or system loses energy,
an equal amount of energy must be gained and vice versa.
Consequently, there is in the change of the form of energy a
certain aptitude to last forever, though not in a form that is
useful and can do work.22 Sometimes this is expressed in
statements such as “Energy is neither created nor destroyed but
only changes form.” Thus, the Law of the Conservation of
Energy treats physical changes in an Aristotelian way. While
adding a precise quantitative mode to the necessary relation of
generation-corruption of form in a physical motion, it parallels
in a specific way the general Aristotelian principle that the
corruption of one thing is the generation of something else, and
conversely. Considered in the light of the Aristotelian principle,
we understand something new, though very general, about the
Law of the Conservation of Energy.
Feynman continues his discussion of energy and the Law of
the Conservation of Energy by means of an analogy in which he
compares blocks, like those with which a child plays, to energy.
Unlike a child’s blocks, however, these blocks are “absolutely
indestructible and cannot be divided into pieces.” They are also
all the same. The idea is that the number of the child’s blocks
21

According to Noether’s Theorem, the Law of the Conservation of Energy follows
necessarily from time symmetry,“meaning that the fundamental laws of physics do not
change over time, so that the results of an experiment with the same initial conditions
are the same whenever the experiment is done. See Jennifer Coopersmith, The Lazy
Universe, Appendix A 6.3 (Oxford: Oxford University Press, 2017), 222-24; Jozef
Hanc, Slavomir Tuleja, and Martina Hancova, “Symmetries and Conservation Laws:
Consequences of Noether’s Theorem,” American Journal of Physics 72 (2004): 428-35.
22
According to the Second Law of Thermodynamics, “the usable energy in an
isolated system is constantly decreasing.” For a discussion of entropy and the Second
Law of Thermodynamics, see Alan Lightman, Great Ideas in Physics (New York:
McGraw-Hill, 2000), 59-115.

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remains constant throughout the child’s play no matter where
the blocks go or how messy and rough the child’s play may be.
After describing the analogy, Feynman applies it to energy and,
with some drama and astonishment, makes the following
points:
What is the analogy of this to the conservation of energy? The most
remarkable aspect that must be abstracted from this picture is that there are no
blocks. . . .
It is important to realize that in physics today, we have no knowledge of
what energy is. We do not have a picture that energy comes in little blobs of a
definite amount. It is not that way. . . . It is an abstract thing in that it does not
tell us the mechanism or the reasons for the various formulas.23

Since the quantity of energy remains the same in energy transformations, we might expect energy to be a kind of substance.
Because we find it easy to use analogies such as that of
Feynman’s indestructible, quantitatively identical blocks, we
might be misled into thinking that in energy conservation some
thing or stuff is being conserved. However, the current state of
our science indicates that this is not the case. The analogy
between blocks and energy and the failure of that analogy
precisely on the point of the blocks’ existence indicates that
23

Feynman, Feynman Lectures on Physics, vol. 1, chap. 4, p. 2. Feynman makes the
same points elsewhere as well: “Of all the conservation laws, that dealing with energy is
the most difficult and abstract, and yet the most useful. It is more difficult to understand
than those I have described so far, because in the case of charge, and the others, the
mechanism is clear, it is more or less the conservation of objects. This is not absolutely
the case, because of the problem that we get new things from old things, but it is really a
matter of simply counting. The conservation of energy is a little more difficult, because
this time we have a number which is not changed in time, but this number does not
represent any particular thing. . . . What we have discovered about energy is that we
have a scheme with a sequence of rules. From each different set of rules we can calculate
a number for each different kind of energy. When we add all the numbers together,
from all the different forms of energy, it always gives the same total. But as far as we
know there are no real units, no little ball-bearings. It is abstract, purely mathematical,
that there is a number such that whenever you calculate it it does not change. I cannot
interpret it any better than that. This energy has all kinds of forms” (Richard P.
Feynman, The Character of Physical Law [Cambridge, Mass.: MIT Press, 1965], 68-70).
The problem of getting new things from old that Feynman also mentions in this lengthy
quotation is precisely the problem form and hylomorphism were meant to solve.

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energy is not a blob or quanta. Particles have energy, but energy
is not a particle nor is it indestructible in an atomist sense.
Though quantifiable, energy is not a thing nor is the conservation of energy about counting discrete units, such as charge
or other such properties. This also seems to be the intuition of
the physics community because physicists do not search for a
fundamental energy particle or stuff as they did for quarks or
the Higgs particle, or as they do now for axions, dark matter, or
the nature of dark energy. Physicists sometimes speak of
photons as having a certain quantum of energy. By this, they
mean that photons possess radiant energy. They do not mean
that photons are energy or energy quanta simpliciter.
Nevertheless, energy and the forms of energy are real. When
Feynman says that energy and the Law of the Conservation of
Energy are abstract, he does not mean that they are not real,
for, of course, we can also speak of energy in very real and
particular ways, such as the number of calories in our food and
the work their energy enables us to do. Feynman is not an
instrumentalist. He is not saying that energy is a useful fiction
or that it does not exist in things.24 The point rather, at least in
part, is that energy, though real, is not a thing in the way that
fluids, rocks, chemical compounds, atoms, and animals are definite things.25 Energy is not the sort of reality discovered as “a
paleontologist might find the first ichthyosaur or a prospector
stumble across the Koh-i-noor diamond” or even like modern
physicists detecting subatomic particles with a particle
24
Throughout his Lectures on Physics, when Feynman speaks of the different forms
of energy, he speaks of them in real and particular ways, such as: “The fact that the
electromagnetic field can possess momentum and energy makes that field very real . . .
and the field itself has such familiar properties as energy content and momentum, just as
particles can have” (Feynman, Feynman Lectures on Physics, vol. 1, chap. 10, p. 9).
25
Physicists influenced by Feynman’s account have considerable difficulty
understanding the way in which energy is real yet is neither a thing nor even a discrete
property: “Energy is a property of matter interacting with matter, not a thing in and of
itself. There is no such thing as energy set free, energy without matter, just as there is no
such thing as free momentum. Physical entities (including light, the most tenuous form
of matter) can produce change—and undergo change—and hence possess energy”
(Eugene Hecht, “Energy and Change,” The Physics Teacher 45 [2007]: 90). Feynman
might not agree without qualification that energy is a property.

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THOMAS MCLAUGHLIN

accelerator.26 On this account, energy as such is not extended in
three dimensions but is only extended per accidens insofar as
what has energy is extended.
Thus, energy is better thought of in Aristotelian terms as a
principle of things in the way that form, act, potency, essence,
and nature are principles. Like form, energy is not a thing. It is
a principle that we understand by what comes from it. Just as
reifying form is a mistake, so too is reifying energy a mistake.27
We may imagine something like lightning when we think of
energy, but lightning is not energy, though it has energy or is
energetic. So too, part of what Feynman means by saying that
energy is abstract is that it is not strictly imaginable. In this,
energy is like form, for, properly speaking, we cannot imagine
forms.
Furthermore, eliminating the blocks implies a more elevated
role for the form of energy. The form cannot be a superficial
overlay or merely the manifestation or avatar of some
underlying energy. Since there are no blocks, nothing energetic
is further determined by the form of energy. Consequently, the
form is that by which something has energy. It is the act by
which something has energy. This is the key implication of
Feynman’s denial that there are energy “blocks”. Since energy is
not a thing, a particle, a stuff, or a property like charge, then, as
far as we know, there is nothing besides the form of energy
which is that whereby something has energy and energy of a
certain kind. Thus, it is the form of energy that makes something be energetic and energetic in a certain definite way. Consider the following interpretation of Feynman’s “there are no
blocks” claim: “By that [Feynman] means we can’t say which of
the various forms in which energy manifests itself represents
what energy ‘really’ is.”28 The statement is acceptable insofar as
is it says that there is no one energy that is what energy really is,
26

Coopersmith, Energy, the Subtle Concept (Oxford: Oxford University Press,
2015), 357.
27
On the distinction between a principle and a thing and the tendency to reify
principles, see James A. Weisheipl, O.P., The Development of Physical Theory in the
Middle Ages (Ann Arbor, Mich.: University of Michigan Press, 1971), 37-40.
28
Robert H. March, Physics for Poets (New York: McGraw-Hill, 1970), 77.

ENERGY AND FORM

15

that there is no “block.” The problem is in retaining the
language of the forms of energy as “manifesting” and
“representing,” for if there are no blocks, then there is no
energy to manifest or represent besides what is caused by the
form. Though a form of energy is an accident, and the subject
of an accident must be in potency to receive it, accidents are not
composed of matter and form but are just forms. An accidental
form is not a thing but a secondary principle of a thing, for its
very essence is to inhere in a subject and make a subject be not
absolutely but in a qualified sense. The subject is the principle of
individuation of accidents, and an accident in a subject is that
which is measured and that through which the subject acts.
Consequently, the form of energy modifies a subject and makes
it be such, or so great, or in some particular condition, much as
the accidental form “musical” makes a man be musical. Thus, if
there are no blocks, the form of energy is an accidental formal
cause in a subject.
Changes in energy as such are not exchanges of “blocks.”
Consequently, the statement that energy is neither created nor
destroyed, which in Feynman’s example is the point of saying
that the blocks are indestructible, obscures an important issue
and easily misleads. Most likely, “neither created nor
destroyed” is not meant in the proper metaphysical and theological sense of creation ex nihilo and annihilation but instead is
used to mean that energy “neither comes to be nor passes away”
or is “neither generated nor corrupted.” The phrase is true if it
is taken to mean that the total amount of energy of a closed
system remains the same, but it can easily be taken to mean that
in receiving or losing a given form and amount of energy a
subject does not come-to-be such or cease-to-be such. What
“there are no blocks” implies is that a subject’s change of energy
is an actualization of a potency. Some subject has a potency for
a form and a quantity of energy that when actualized must be
matched by a corresponding but opposite actualization of a
potency in a subject so that the net change in the amount of
energy is zero (for a closed system). To speak improperly for
emphasis, when a subject undergoes a change in energy, energy

16

THOMAS MCLAUGHLIN

comes to exist and ceases to exist but does so in such a way that
the total amount of energy remains the same.29
Since in a change of energy a body or some subject undergoes a change so that it gains or loses some accidental form of
energy or some amount of a form of energy, the form of energy
in such changes is a principle of change and of being. It is a
principle of change because a form of energy is the new term
(considered simply) that is acquired through the change. What
undergoes the change in energy comes to be formed accidently
according to its new form of energy, and the newly acquired
form or forms of energy limit the change in energy to a
determinate outcome. The form of energy is a principle of being
because, in making a thing have a certain quantity of a given
kind of energy, it makes it be and continue to be such, and thus
it is a cause, an accidental formal cause. Thus, the Law of the
Conservation of Energy combined with its treatment of the
forms of energy and with Feynman’s “there are no blocks”
claim supports the view that the various forms of energy not
only are kinds of energy but also are accidental formal causes
that determine things to be such as they are.
II. ENERGY, ABSTRACTION, AND MATHEMATICS
Feynman does not develop his thoughts about energy in this
direction. Instead, he claims that we do not know what energy
is and focuses on the abstract, mathematical character of energy
and of the Law of the Conservation of Energy. Energy and the
conservation of energy are undoubtedly mysterious, and they
are certainly quantifiable and are formulated mathematically.
Without the use of mathematics, we would not have discovered
29
Strictly and properly speaking, only the composite and not its form or its matter is
generated or corrupted, though we may speak of forms coming to be or passing away
per accidens insofar as the composite is a subject of change per se. Therefore, strictly
speaking, energy does not come to be or pass away since energy is not a composite.
Saying that a form of energy comes to be and passes away or that the energy changes
means that a body or some subject undergoes a change so that it comes to be not
absolutely but accidentally by gaining or losing some accidental form of energy or some
amount of a form of energy. Energy is also not a subject of change since it is an
accident, though we sometimes speak improperly of accidents as subjects of change.

ENERGY AND FORM

17

the Law of the Conservation of Energy.30 However, we should
be careful not to think of them as merely abstract mathematical
notions. Feynman’s claims are usefully contrasted with those of
another physicist, A. P. French, writing for the MIT Introductory Physics Series of textbooks:
Of all the physical concepts, that of energy is perhaps the most far-reaching.
Everyone, whether a scientist or not, has an awareness of energy and what it
means. Energy is what we have to pay for in order to get things done. The
word itself may remain in the background, but we recognize that each gallon
of gasoline, each Btu of heating gas, each kilowatt-hour of electricity, each car
battery, each calorie of food value, represents, in one way or another, the
wherewithal for doing what we call work. We do not think in terms of paying
for force, or acceleration, or momentum. Energy is the universal currency that
exists in apparently countless denominations; and physical processes represent
a conversion from one denomination to another.31

French tells us that scientists and nonscientists alike all have “an
awareness of energy and what it means,” whereas Feynman tells
us that “we have no knowledge of what energy is.” Both quotations are taken from authoritative and respected textbooks.
The issues here are undoubtedly difficult, but, clearly, we must
at least make some distinctions.
In contrast to Feynman’s analogy of blocks, French likens
energy to a “universal currency” that occurs in “countless denominations.” The universal-currency analogy captures the
breadth of the notion of energy, the convertibility of its forms,
and its conservation. It also implies, though it does not state so
explicitly, that energy is not like a coin that can be passed
around. The “universal currency” analogy is an abstraction
similar to Feynman’s blocks. Just as there are no blocks, so too,
30
“Feynman shows us that it is only by uncovering the individual mathematical
formulae that energy will be uncovered. We shall, therefore, track the emergence of
these formulae—the non-existent ‘blocks of energy’—through the history of their
discovery” (Coopersmith, Energy, the Subtle Concept, 4).
31
A. P. French, Newtonian Mechanics (New York: W. W. Norton & Co., 1971),
367. French remarks on the passage quoted above that “The above remarks do not
really define energy. No matter. It is worth recalling once more the opinion that H. A.
Kramers expressed: ‘The most important and most fruitful concepts are those to which
it is impossible to attach a well-defined meaning’” (ibid.).

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THOMAS MCLAUGHLIN

there is no real universal currency. A universal currency is not
one of the real currencies in which energy exists. Real
currencies, like the forms of energy, are specific, and they come
in many denominations.32 Similarly, just as there are only
different currencies and their ratios, so too there are only
different forms of energy and their ratios, ratios that are fixed
in nature and not subject to fluctuations. Consequently, on
French’s currency analogy, the form is also that by which
something has energy.
Energy and the Law of the Conservation of Energy are
abstract in the sense that they can signify a commonality that
leaves out many specific and individual features without
rejecting them. “Energy,” considered just as such, does not exist
as a thing or stuff in nature any more than “animal” exists as a
thing in nature. Of course, just as “animal” is not a mere generic
abstraction because we can also speak of this kind of animal and
of this particular animal, so too the term “energy” can be used
by itself in a very abstract way but also can be used to signify a
specific form of energy or the energy of a particular thing, as
French does in the passage quoted above. Aristotle likewise can
use the term “form” in a very abstract way or in more specific
or particular ways, as when he speaks of the form “musical” or
of an individual musician. The Law of the Conservation of
Energy says that for all the forms of energy some commonality
is conserved throughout all changes in energy even though what
is conserved is not a thing, a mechanism, or a unit of some kind.
The commonality itself, like a universal currency, does not exist
as such except in a mind. This is indeed abstract, but we can
nevertheless speak of energy and the forms of energy in very
specific, particular, and physical ways.
French’s currency analogy includes a quantitative and mathematical understanding of energy and the conservation of energy,
32

In addition, French’s claim that energy exists in “apparently countless
denominations” indicates that we can think of forms of energy in specific as well as
generic ways in keeping with the claim made earlier in this article. Similarly, when
French speaks of “each gallon of gasoline, each Btu of heating gas, each kilowatt-hour of
electricity, each car battery, each calorie of food value” he is also affirming that we can
think of the form of energy in particular or individuated ways as well.

ENERGY AND FORM

19

but unlike Feynman, French does not say it is “abstract, purely
mathematical, that there is a number such that whenever you
calculate it it does not change.” He emphasizes a physical
understanding as well. Feynman’s difficulty would seem to be
that there is no thing that is energy. Consequently, since there is
no thing, we do not know to what the mathematics is referring,
and so he says that it is a purely mathematical, abstract law. It is
purely mathematical because the number that is conserved does
not refer to a known thing or a discrete countable property of
things, at least not for the sort of realities with which Feynman
is familiar. “There are no blocks” means that we do not know
of an underlying physical reality that is energy. What we know
is the mathematics. However, as French and other scientists
point out, we do have some physical awareness and understanding of energy.33 We could not treat energy mathematically
if we did not know something about it and have some physical
understanding of it—unless we were to regard energy and the
conservation of energy as something like Ptolemy’s epicycles,
which Feynman does not do.
Energy is identified with activity, for, like currency, it is that
by which things get done. The currency analogy is dynamic, is
related to work, and captures the active sense of energy; blocks,
by contrast, are not energetic but static and do not suggest
work. Our manner of speaking indicates this understanding, for
we say that gasoline, electricity, and food have energy and do
things in virtue of that energy. We are aware of the energeia of a
lightning bolt, and we do not walk under ladders because we
are aware of the potential energeia of heavy bodies. Likewise,
physicists have a discipline called high-energy physics and speak
of gamma rays as high-energy photons and of cosmic rays as
high-energy particles. Astronomers speak of the energy source
of quasars and active galaxies and of nuclear energy as the
energy that powers the stars. Similarly, in ordinary usage, we
speak of “energy drinks” and “energy bars.” We talk about
33
“Although energy was and is considered an imponderable concept, physicists (and
scientists in other disciplines) were still able to develop a sophisticated understanding of
it that goes beyond a mere mathematical description and formalism” (Harrer, “On the
Origin of Energy,” 454).

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THOMAS MCLAUGHLIN

“energy resources,” an “energy crisis,” and an “energy policy.”
We speak of inequities in the availability of energy to different
peoples. The notion of energy is deeply woven into agriculture,
engineering, economics, public policy, business, industrialization, and international relations. It is important even in
sciences such as paleontology and neuroscience. The early scientific development of the notion of energy and the conservation
of energy was deeply connected to the rise of the machine age.34
Energy is foundational for human civilization, and part of
human history can be written as the increasing mastery that
human beings have gained over energy.35
Many of these uses of the term “energy” are continuous with
the use of the term in the hard sciences. Indeed, the breadth of
its use, including uses beyond the hard sciences, indicates that
the notion of energy is more general than its specific scientific
meanings. Thus, we should not think of energy and of the Law
of the Conservation of Energy as mere abstractions or as only
mathematical notions, for scientists and nonscientists both speak
of energy as determinate, particular, physical, and active. In
trying to understand energy, just as we do not want our
familiarity with it to make us think we know more than we do,
so too we do not want to deny or lose our ordinary and basic
understanding of the meaning of the term, however rough,
vague, and crude, it may be. We do not move from what is
evident and intelligible quoad nos to what is evident and intelligible per se by denying what we know quoad nos.36
34
“A mathematical description of nature, leading to the eventual discovery of
energy, emerged slowly, over millennia, and was prompted, more than anything else, by
one endeavor—the construction of devices. These were tools, simple machines, and
‘engines’, discovered independently, again and again, all over the world” (Coopersmith,
Energy, the Subtle Concept, 5). “There were also mathematical advances arising from
astronomy, warfare, and trade—but those arising from machines had an especial
relevance to energy” (ibid., 377).
35
“The history of man’s conquest of his material environment can be written as the
story of the mastery of energy. This single concept is probably the foremost bridge
between the abstract world of physical theory and the practical one in which men try to
get things done” (March, Physics for Poets, 67).
36
“Through things better known we arrive at a knowledge of things unknown. Now
things are said to be better known in two ways. Some are better known in regard to us

ENERGY AND FORM

21

In sum, French speaks about our familiarity with energy and
its different forms and how we use the term. Certainly, as he
points out, we know something about energy and its different
forms. Feynman would seem to mean, especially since he italicizes the word “is” (“we have no knowledge of what energy is”)
that we do not know what energy is in some fundamental or
absolute sense and that it is not like other realities that we do
know. He is making a philosophical point in a pedagogically
and rhetorically effective way. His point, especially since he
states his claim in the negative, may also be that we do not even
know what kind of reality energy is, for he does not say what
kind of knowledge we are lacking. Feynman’s discussion might
be regarded as an important admission of the limits of our
current scientific understanding, but it may also reflect the
limits of his own prior, general natural philosophy, a natural
philosophy to which energy may not conform and which lacks a
notion of formal causality.
III. ENERGY AND MATTER
Although Feynman does not draw out the hylomorphic
implications of his understanding of energy, another Nobelprize-winning physicist, Murray Gell-Mann, unintentionally
goes further in this direction. Since energy comes in different
forms and because of the Law of the Conservation of Energy,
some thinkers have taken the notion that “energy is neither
created nor destroyed” to mean that energy is a special substance and that the different forms of energy are different
manifestations of this substance. In addition, viewed against the
nineteenth-century background of the laws of Conservation of
Matter and of Conservation of Energy, Einstein’s famous
equation E = mc2 may seem to suggest that matter and energy

such as the composite and the sensible; others are better known absolutely and in
themselves, as the simple and the intelligible. Because we acquire knowledge by
reasoning, we must proceed from what is better known to us” (I Nic. Ethic., lect. 4
[Marietti ed., 52; Thomas Aquinas, Commentary on Aristotle’s Nicomachean Ethics,
trans. C. I. Litzinger, O.P. (Notre Dame, Ind.: Dumb Ox Books, 1993)]).

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THOMAS MCLAUGHLIN

are two distinct substances that can be mutually converted into
one another. According to Gell-Mann, this view is an error:
All matter possesses energy, and all energy is associated with matter. When
people refer carelessly to matter being converted into energy (or vice versa), they
mean simply that certain kinds of matter are converted into other kinds. For
example, an electron and a related (but oppositely charged) particle called a
positron can come together and turn into two photons, a process often described
as “annihilation” or even “annihilation of matter to give energy.” However, it is
merely the transformation of matter into other matter, of certain forms of energy
into other forms.37

An electron is a negatively charged atomic particle of very low
mass. A positron is the antimatter counterpart of the electron.
Unlike an electron, it has a positive charge.38 When an electron
and a positron meet, they are transformed into two gamma-ray
photons, a form of very high energy electromagnetic radiation.
Gamma-ray photons, unlike electrons and positrons, do not
possess mass.39
The transformation of an electron and a positron into a pair of
gamma rays is often called, however improperly, “annihilation”
for at least two very significant reasons. In the transformation, the
entire mass of the electron/positron pair is converted into the
energy of the gamma-ray photons.40 Since mass was historically
37
Murray Gell-Mann, The Quark and the Jaguar (New York: W. H. Freeman and Co.,
1994), 124. Gell-Mann received the 1969 Nobel Prize in Physics for his contributions and
discoveries concerning the classification of elementary particles and their interactions. He is
a codiscoverer of quarks and quark theory.
38
“The generalization of this, that for each particle there is an antiparticle, turns out
to be true. In the case of electrons, the antiparticle has another name—it is called a
positron, but for most other particles, it is called anti-so-and-so, like antiproton or
antineutron” (Feynman, Feynman Lectures on Physics, vol. 1, chap. 2, p. 8).
39
“The quanta of electric and magnetic energy in a radio wave or a light wave are
called photons. . . . Photons display particle properties: they have energy, momentum,
and spin-angular momentum. Their mass is zero, as is required by the theory of
relativity, according to which only a zero-mass particle can move at the speed of light
yet have finite energy” (Hans C. Ohanian, Physics, vol. 2, Interlude G [New York:
W. W. Norton & Co., 1985], G-5). Ohanian is a former associate editor of the
American Journal of Physics.
40
“This theory of equivalence of mass and energy has been beautifully verified by
experiments in which matter is annihilated—converted totally to energy: An electron and a

ENERGY AND FORM

23

identified with matter, the complete transformation of mass into
the energy of massless particles was often conceived of as the
“annihilation” of matter or as the transformation of matter into
energy.41 However, mass is now understood as a form of energy
and, as Gell-Mann states, photons are a kind of matter and have a
different form of energy. The “annihilation” of mass does not
increase the amount of energy. The amount of energy remains
the same throughout the interaction, but the subject undergoes
a change in which one form of energy, mass, is lost, and another
form of energy, that of the gamma-ray photons, is gained.42
Gell-Mann does not say what matter and energy would then be,
though his account strikingly raises that question, especially since
massless particles are regarded as matter.
In addition, the transformation of an electron/positron pair
into gamma-ray photons is not the rearrangement of more
fundamental particles. Unlike molecules (which are composed of
atoms) and atoms (which are composed of protons, neutrons, and
electrons), and protons and neutrons (which are composed of
positron come together at rest, each with a rest mass m0. When they come together they
disintegrate and two gamma rays emerge, each with the measured energy of m0c2. This
experiment furnishes a direct determination of the energy associated with the existence of
the rest mass of a particle” (Feynman, Feynman Lectures on Physics, vol. 1, chap. 15,
p. 11).
41
The reverse process is called particle creation: “Antimatter is not readily available
in large amounts. On Earth, antiparticles can only be obtained from reactions induced
by the impact of beams of high-energy particles on a target. These collisions occasionally
result in the creation of a particle-antiparticle pair. Such pair creation is the reverse of
pair annihilation” (Ohanian, Physics, 1:186). The “annihilation” and “creation”
interactions of electrons, positrons, and gamma rays are not so simple as indicated here.
They also involve drawing upon the quantum vacuum. Also, in nuclear and chemical
reactions, a percentage of the mass of the original reactants is also “lost,” that is,
changed into other forms of energy. The conversion is quite small in chemical reactions
but dramatic in nuclear ones.
42
“A photon is not just ‘energy.’ There is no such thing as ‘pure energy.’ Rather, the
photon is the particle of the electromagnetic field. It does possess the attribute of
energy. The electron and positron possess the property of rest mass (as well as energy),
but they are not ‘mass’ (in the sense of ‘being inertia’). Perhaps, because they are
‘matter,’ the electron and positron are mass in the sense of ‘lump of stuff.’ That sense of
mass, however, is different from the sense in which the word mass is used in the
equation E =mc2” (Ralph Baierlein, “Does Nature Convert Mass into Energy?,” American
Journal of Physics 75 [2007]: 323).

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THOMAS MCLAUGHLIN

quarks), electrons, positrons, and gamma-ray photons are not
composed of particles or any other formed parts. The old
atomistic forces-and-rearrangement-of-particles model of physical
change has seemingly been abandoned. Instead, the transformation of an electron/positron pair into gamma-ray photons is
like the change of one Aristotelian element into another, such as
air into fire. On an Aristotelian account, what persists through the
change so that the change is not annihilation or creation is not
something that is a kind or that has form. It is prime matter.
Gell-Mann’s account suggests hylomorphism: that matter is an
underlying potentiality and that energy is a form. The transformation of one kind of matter and one form of energy into
another and of massive bodies into massless bodies implies that
energy and matter are not things or substances but coprinciples of
things. Like Aristotle’s matter and form, matter and energy are
presented by Gell-Mann as distinct but correlative. Matter and
energy are not given apart from each other but are always
together and related. There is always matter, and there is always
energy, though not always the same form of energy. The
impression of hylomorphism is furthered inasmuch as the energy
of the electron’s and positron’s mass and the photons’ energy are
identified with form whereas matter is left unspecified, except in
saying that it can possess different forms of energy and that
matter, such as electrons, positrons, and photons, comes in
different kinds. Gell-Mann thereby strengthens, develops, and
compliments the points made in discussing the Feynman and
French accounts of energy.
Although Gell-Mann does not explicitly acknowledge the
Aristotelian principles of matter and form or act and potency,
Heisenberg famously applied these principles to particle physics.
However, he identified energy with prime matter and potency
and not with form and act. According to Heisenberg,
All the elementary particles are made of the same substance, which we may
call energy or universal matter; they are just different forms in which matter
can appear.
If we compare this situation with the Aristotelian concepts of matter and
form, we can say that the matter of Aristotle, which is mere “potentia,” should

ENERGY AND FORM

25

be compared to our concept of energy, which gets into “actuality” by means of
the form, when the elementary particle is created.43

Energy, according to Heisenberg, is comparable to mere
potentiality, a formless indeterminate, universal principle that is
open to gaining or losing different forms and out of which all
the different kinds of elementary particles are made. On
Heisenberg’s account, energy is like prime matter.44 Form is
understood in an Aristotelian sense, since by means of form,
energy, regarded as potentiality, is actualized in making
elementary particles. The different kinds of elementary particles
are due to different forms that actuate the underlying energy.
Since Heisenberg says that form is that by which energy gets
into actuality, form would also be an act and as such would be a
principle of the elementary particles’ activity. Form, on
Heisenberg’s view, would seem to function as a formal cause.
Of course, the statement “they are just different forms in which
matter can appear,” especially with its use of the words “just”
and “appear,” might suggest a weaker account of form. In any
43

Werner Heisenberg, Physics and Philosophy (New York: Harper & Brothers,
1958), 160. See also idem, “Planck’s Discovery and the Philosophical Problems of
Atomic Physics” and “Discussion of the Lecture of Werner Heisenberg,” in On Modern
Physics (New York: Collier Books, 1962), 16-17, 23-24, 27, 40, 43-44; and idem,
Across the Frontiers, trans. Peter Heath (New York: Harper & Row, 1974), 21-22.
Heisenberg’s view was embraced by William Wallace. For Wallace’s view and
Heisenberg’s response to an inquiry by him, see William A. Wallace, O.P.,
“Elementarity and Reality in Particle Physics,” in From a Realist Point of View, 2nd ed.
(Washington, D.C.: University Press of America, 1983), 206-8. Wallace later modified
his view in response to Wolfgang Smith, The Quantum Enigma: Finding the Hidden Key
(Peru, Ill.: Sherwood Sugden & Company Publishers, 1995). See William A. Wallace,
O.P., “Thomism and the Quantum Enigma,” The Thomist 61 (1997): 455-68. In this
review, when discussing atomic physics, Wallace says that “‘form’ (morphe) functions as
an energizing and stabilizing principle in an inorganic nature.” This statement closely
relates energy with form and implies that energy is an act and not a potentiality since
the form is energizing. See, however, David S. Oderberg, “Is Prime Matter Energy?,”
Australasian Journal of Philosophy (January 12, 2022), published online at
https://doi.org/10.1080/00048402.2021.2010222. Oderberg’s article appeared after the
present article was prepared for publication.
44
“Primary matter does not exist by itself in nature, since it is not actually being, but
potentially only; hence it is something concreated rather than created” (STh I, q. 7, a. 2,
ad 3).

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THOMAS MCLAUGHLIN

case, assuming that for Heisenberg the elementary particles are
substances, then the forms that bring them into actuality are
substantial forms.
Since, according to the Law of the Conservation of Energy, a
quantity of energy is conserved in the transformation of something from one form of energy to another, identifying energy
with prime matter might seem plausible because in Aristotelian
natural philosophy matter persists through a change while forms
are gained and lost. Matter, to use the language of physics, is
conserved. Also, at least some energy transformations seem to
involve substantial changes in which a new kind of thing comes
to be, which would also require an underlying prime matter.
Prime matter, of course, is not a thing, and so, Heisenberg’s
position might also seem to fit with some points that Feynman
makes, such as the claim that there are no blocks.
We can be sympathetic to Heisenberg and maintain that he is
correct to draw upon Aristotle and hylomorphism, and be
appreciative of his use of Aristotle’s notion of potentiality in
understanding quantum mechanics. However, energy cannot be
prime matter, and the conservation of energy cannot be the
conservation of prime matter.45 The conservation of energy is
even one reason that energy cannot be prime matter. According
to the Law of the Conservation of Energy, for a closed system, a
particular quantity of energy is the same at the beginning of a
physical process as it is at the end of the process. This means
that a particular quantity is conserved. However, prime matter,
as such, is not quantified. Unlike energy, it cannot be measured
in joules. Consequently, a particular quantity of prime matter
cannot be conserved in a physical process, and energy cannot be
prime matter. Someone might object by pointing out that we
must distinguish between prime matter considered in itself and
prime matter considered as it exists.46 Considered in itself,
45

“I must, however, add the reservation that neither my studies of Aristotle nor of
Aquinas have been thorough enough to permit me the formulation of a well-founded
opinion concerning the concepts ‘potency’ and ‘prime matter’” (Heisenberg,
“Appendix” to Wallace, “Elementarity and Reality in Particle Physics,” 259).
46
STh I, q. 7, a. 2, ad 3; STh I, q. 14, a. 2, ad 3; STh I, q. 15, a. 3, ad 3; STh I, q. 84,
a. 3, ad 2.

ENERGY AND FORM

27

prime matter is pure potency without any form or actuality. In
itself, it is potency to substantial form and lacks all composition.
As such, prime matter cannot exist on its own and cannot be
quantified. However, considered as it exists, prime matter is
never without (substantial) form and actuality. It exists only
with and actuated by some form as a principle of a composite
substance.47 Prime matter, so considered, would then exist in
some corporeal quantity.48 Thus, the objector might argue that
we can speak of a quantity of prime matter not as prime matter
is in itself but as it exists in things. We might then speak, for
instance, of 160 joules of prime matter and of those 160 joules
of prime matter being conserved.
However, even if we consider prime matter as it exists in
things, energy cannot be prime matter since the different kinds
of energy are accidents. There are two broad classes among the
kinds of energy, kinetic energy and potential energy.49 Kinetic
energy is the energy of motion and potential energy is the
energy of position. Mass energy might be treated as a third
class. Thus, all forms of energy depend on motion or on
position or mass. However, motion, position, and mass do not
exist on their own but depend upon a body or a system that is
moving, is in a position, or has mass. Therefore, energy is a
dependent or secondary reality, and, thus, it is an accident and
not a substance or a fundamental principle of a substance, such
as prime matter. Identifying energy with prime matter is a
category mistake.50
47

Quodl. III, q. 1, a. 1.
I Gen. and Corrup., lect. 14 (Conway and Larcher, trans., 99).
49
“Upon careful examination, all these various forms fall into just two main types of
energy: kinetic, the energy of motion; and potential, the energy of the interaction of
parts of a system” (Coopersmith, Energy, the Subtle Concept, 355).
50
At this point, someone might reasonably ask, given that the forms of energy are
accidents, in which of the categories should they be classified? The question goes
beyond the scope of this paper, which is limited to arguing that the forms of energy are
accidental forms in the Aristotelian/Thomistic sense. If I were to speculate, I would say
that the forms of energy would in some sense be classified in the categories of quantity
and quality since something’s energy is so much of a certain kind. We say, for instance,
that a certain lump of coal has 10,000 joules of chemical energy. However, except as a
manner of speaking, we do not want to assert that energy itself has a quantity since
48

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THOMAS MCLAUGHLIN

Since the forms of energy, such as electromagnetic or
chemical energy, are accidents, they are in a substance or subject
and make a substance be such. They do not actuate prime
matter to make something be, but instead presuppose a
substance or system that they further actuate. Energy might be
regarded as what is sometimes called secondary matter (see
below), but substantial, not accidental, forms actuate prime
matter and compose substances. On Heisenberg’s view, the
form of energy would not be correlative to the underlying
energy understood as prime matter, for the forms of energy are
not substantial forms. Similarly, the claim that the elementary
particles are made of energy would be rather unusual in physics,
for physicists say that particles have energy, not that they are
made of energy. As indicated in the discussion of Gell-Mann,
electrons and positrons have mass energy, and gamma-ray
photons have radiant energy. Their “annihilation” and “creation” may give the appearance that energy is prime matter, but
it would be a mistake to say that an electron is or is made out of
mass energy or that a gamma-ray photon is or is made out of
radiant energy. Likewise, the forms that Heisenberg says actuate
energy to create an elementary particle do not correspond to
known forms of energy, and Heisenberg does not say what
kinds of energy the particles themselves would be. Perhaps one
day physics may advance to the point where substances or
substantial forms may be understood as forms of energy, but
that is not now the case.

energy is not a subject. The coal, not the energy, has the quantity. Furthermore, since
energy is active and, in the case of potential energy, also receptive, the forms of energy
in some way would be in the categories of action and passion as well. Since potential
energy is the energy of position, it might also belong in the categories of relation and
place. Energy is perhaps fundamentally in the category of quality, since it is tied up with
powers and their acts. These are dependent upon substance, through quantity, and
qualities also ground relations as well as actions and passions. Kinetic energy poses a
special problem. We might wonder whether kinetic energy, the energy of motion, is
truly a form in the Aristotelian/Thomistic sense, since for Aristotle and Aquinas, motion
is not a form, which suggests that properly speaking neither is kinetic energy, and, thus,
it does not belong in a category, except perhaps by reduction. However, these questions
and issues must be left to future investigations.

ENERGY AND FORM

29

The same point might be made in another way. The relevant
change through which prime matter persists is a substantial
change, but many changes in energy are not substantial changes,
such as the change in the gravitational energy of an apple falling
from a tree. The apple and the Earth persist through the fall,
and at this level of explanation there is no need to invoke prime
matter as the conserved energy. And in those changes in energy
that do arguably involve substantial changes, such as the change
of an electron/positron pair into gamma-ray photons or the
generation of new particles in accelerator experiments, the
forms of energy, as noted above, are not substantial forms, and
so are not proportioned to prime matter. In these cases,
alteration and substantial change are confused. Alteration is the
way to generation and corruption, for it brings on and takes
away the proper dispositions of things, but it is not substantial
change. Consequently, though the change of an electron/
positron pair into gamma-ray photons may be a substantial
change, nevertheless mass energy and radiant energy are
accidents. Finally, if energy were prime matter, then potential
energy would be potential prime matter, a potential pure
potentiality, a notion that is contradictory.51
Someone might maintain that energy is secondary matter, a
body or substance already constituted by prime matter and
substantial form, and that the Law of the Conservation of
Energy parallels Aristotle’s prime matter with respect to
something secondary, a secondary potency, that persists through
a change.52 However, such a secondary potency would be in
51
“If prime matter were generated, there would be a matter in it, out of which it
came to be. There would, therefore, be a matter prior to prime matter, and so prime
matter would not be prime. There would also be a form in it, by which prime matter
would differ from that out of which it came to be. But, prime matter of itself is without
any form” (Bobik, Aquinas on Matter and Form and the Elements, 29; the quotation is
from Bobik).
52
“For example, there is something that is in potency to being a man, like sperm and
menstrual blood [ovum]; and there is something that is in potency to being white, like
man. Both what is in potency to substantial existence, and what is in potency to actual
existence, can be called matter; like sperm, the matter of man; and man, the matter of
whiteness. But they differ in this: the matter which is in potency to substantial existence
is called the matter out of which; and that which is in potency to accidental existence is

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THOMAS MCLAUGHLIN

something, something that has a definite quantity of energy
regarded as a kind of potency. It is not obvious how a definite
quantity of potency, 200 joules for example, would not only
retain its identity through a change but would also avoid
Feynman’s claim that “there are no blocks,” especially since
Feynman extends “blocks” to include countable properties, such
as charge. Furthermore, if energy were regarded as a definite
quantity of secondary matter that persisted through a physical
process, potential energy would still be a potential potential,
which is a problematic notion. Of course, an objector might
reply that a potential potential would not be problematic since
first potency implies second potency. The objection would
appeal to the distinction between first and second potencies and
first and second acts to argue that energy is secondary matter.
To become a genuine counterargument, such an objection
would require considerable development to formulate it
intelligibly in a way that fits with the physics of energy. Only
then could it be examined and addressed. This will not be
attempted here.53 Instead, a ready answer is at hand if energy is
identified with act and form. “Potential” in potential energy is
potentiality to actual energy, to a certain actuality and form.
For example, “potential” in gravitational potential energy is
potentiality to a certain form of energy, namely, a quantity of
kinetic or gravitational energy. Potential energy would then be a
potency of the secondary matter, a potency to a specific form by
which something has energy. Unlike Heisenberg’s interpre-

called the matter in which. Properly speaking, however, what is potency to substantial
existence is called prime matter; whereas what is in potency to accidental existence is
called a subject” (De Princ. Natur., c. 1 [Bobik, trans., 4).
53
Since the discussion concerns the hypothesis that energy is secondary matter,
presumably the first potency would not be prime matter and the second potency
secondary matter. The argument might be made by using the analogy to geometrical
knowledge that Aristotle and Aquinas applied to heavy bodies falling. See Aristotle,
Physics 8.4.255a30-255b31 and Thomas Aquinas, VIII Phys., lect. 8 (Blackwell, Spath,
and Thirlkel, trans., 1029-36). Such an argument could also draw upon the definition of
energy as the capacity for work or upon the notion of “the potential” in physics to argue
that energy is potentiality and then attempt to make sense of potential energy as a
potential potentiality.

ENERGY AND FORM

31

tation, there is no odd separation of energy from its form. The
form of energy is the source of the energy as a formal cause.
However, the main objection to interpreting energy as prime
matter or secondary matter is that this is to identify energy with
potentiality, and in ordinary and scientific use the meaning of
“energy” is opposed to that of prime matter and potentiality. As
the previously quoted passage from A. P. French indicated,
“energy” means something active or actual. That is how
scientists and ordinary people use the word. Similarly, GellMann and others typically use the term “energy” in contrast to
matter. Even a problematic phrase such as “pure energy” usually
means an especially intense, raw, unformed activity, a kind of
Heraclitian fire.54 It is not meant to designate an underlying
receptivity that lacks actuality. Energy, as argued previously, is
best regarded as a general, abstract term signifying a certain
commonality of all the different kinds of energy. Energy is
energetic and should be identified with form and act and not
54
Heisenberg likens energy to Heraclitus’s fire: “All elementary particles are
composed of the same substance, that is, energy. They are the various forms that energy
must assume in order to become matter. Here the pair of concepts of ‘content and
form,’ or ‘substance and form,’ from Aristotle’s philosophy reappears. Energy is not
only the force that keeps the ‘all’ in continuous motion, it is also—like fire in the
philosophy of Heraclitus—the fundamental substance of which the world is made.
Matter originates when the substance energy is converted into the form of an
elementary particle” (Heisenberg, “Planck’s Discovery,” 23-24). He repeats this view in
Across the Frontiers, 22. His view that energy is like Heraclitus’s fire and that energy is
“the force that keeps the ‘all’ in continuous motion” shows that he himself identifies
energy with act and activity. Of course, energy cannot be both Aristotle’s prime matter
and like Heraclitus’s fire, though perhaps Heisenberg conceives of Aristotle’s “mere
potentia” as a kind of underlying active substance. However, energy cannot be a
substance and be prime matter because prime matter is not a substance but is a principle
of a substance, nor does prime matter exist in and of itself as does a substance. Energy
also cannot be both matter and “that which moves” because matter as such is a passive
potency and not an active principle. Matter is not “that which moves.” The conception
of energy as like Heraclitus’s fire and as “that which moves” also implies a weakened
conception of form, since the activity of energy would not come from the form but from
energy itself conceived as an element like Heraclitus’s fire. Thus, Heisenberg contrasts
form with “content” and “substance.” Finally, the view that energy is a special substance
also implies that the different forms of energy, and indeed all forms, including those of
the elementary particles, are accidents of that energy substance, a view that Heisenberg
himself does not seem to espouse.

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THOMAS MCLAUGHLIN

with matter. Of course, someone might point out that we also
speak of energy in passive ways when we speak of potential
energy. This is certainly the case. Energy, in addition to being
divided according to the forms of energy, is also divided
according to potential and kinetic energy. However, when we
speak of potential energy, we are speaking of something as
having a potency to energy, as potentially energetic but not yet
energetic. If Heisenberg did mean energy in some passive or
potential sense, then he would need to say not “energy” but
“potential energy,” which would be interesting indeed. He
would be identifying a new kind of potential energy.55 Consequently, we can hold that energy transformations require an
underlying matter, and yet deny that the underlying matter is
energy. Energy cannot be simply identified with matter, either
prime matter or secondary matter.
In his thinking about energy and the different forms of
energy, Heisenberg has perhaps been misled in two ways. First,
unlike animals, which are substances and matter/form
composites, the forms of energy are accidents and so are not
matter/form composites. The very nature of an accident is to be
in a subject, but when we speak of accidents alone and
conceived apart from a subject, we have to treat and speak of
them as substances.56 For example, “shape” is an accident in and
of a subject, but we sometimes refer to shapes as things, as
squares, cubes, circles, and spheres. However, “shape” is an
accidental form. We emphasize it as an accidental formal cause
by saying, awkwardly, that squareness is that by which
something is square or sphereness is that by which something is
spherical. Likewise, when we speak of the forms of energy, we
are often speaking in the abstract, as if the forms of energy were
things. Heisenberg has perhaps been misled by the way we
speak of accidents in the abstract as things, as when, for
instance, we speak of energy or a form of energy as having a
quantity, as if energy were a subject.
55
Heisenberg may have been thinking of quantum vacuum or zero-point energy. See
Helge Kragh, Quantum Generations: A History of Physics in the Twentieth Century, rev.
ed. (Princeton: Princeton University Press, 2002), 72-73, 158-59, 162.
56
VII Metaphys., lect. 1 (Marietti ed., 1254).

ENERGY AND FORM

33

Second, Heisenberg has perhaps also confused the logical
distinction between genus, species, and difference with the real
distinction between a thing’s composite principles, such as
matter and form. Man is composed of matter and soul as two
constituent principles that make up a third reality, but in the
sentence “Man is a rational animal,” “rational” and “animal”
designate the difference and the genus and are not constituent
parts that make up a third reality. We do say that the genus, in a
way, is taken from matter and that the specific difference, in a
way, is taken from form. But the genus is not matter and the
difference is not form. The genus “signifies indeterminately
everything in the species and not the matter alone. . . . The
difference designates the whole and not the form alone.”57
Heisenberg may have been misled by this similarity into
regarding the relationship of “forms of energy” to “energy” as
an instance of the relationship of form to matter, whereas it is
more like the relationship of species to genus. The mistake is
easily made because matter and form, though really distinct
coprinciples, are not separable like a ball and a bat or even like
the wings of a bird.58
What is it, then, that is conserved and persists through a
change governed by the Law of the Conservation of Energy? It
cannot be the form, for the form is the very thing that is lost in
a change and, strictly speaking, the form is not quantifiable.
Since the form does not persist through the change, then, at
least to some extent, something actual does not persist. We may
rightly say that matter persists throughout any energy transformation, but, as argued above, that is not what the conservation of energy refers to as conserved. We must distinguish
between the conservation of measured quantities and the
57
De Ente, c. 2 (Thomas Aquinas, On Being and Essence, 2nd rev. ed., trans. and
notes by Armand Maurer, C.S.B. [Toronto: The Pontifical Institute of Mediaeval
Studies, 1968]). See also STh I, q. 50, a. 2, ad 1.
58
Heisenberg may also have been misled by phenomena similar to those discussed by
Gell-Mann: “For according to relativity theory, the high kinetic energy of the colliding
particles can be transformed into mass, and is actually used in generating new
elementary particles. In reality, therefore, there is no real splitting of the elementary
particles, but rather an engendering of new particles of this kind, from the energy of
motion of the incoming particles” (Heisenberg, Across the Frontiers, 21).

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THOMAS MCLAUGHLIN

persistence of beings. “Conserved” and “persists” must be
distinguished so that what is “conserved” with respect to the
conservation of energy is not something that “persists” through
a change. As Feynman describes the conservation of energy,
there is no persisting thing, unit, or mechanism that is the
energy that is conserved through an energy transformation.
Though the same quantity of energy is present throughout a
physical process, that quantity is not the quantity of a thing
persisting throughout the process. Put in another way, if a
system at the beginning of a process has, for example, 100
joules of energy, then, assuming the system is closed, it must
have 100 joules of energy throughout and at the end of the
process. However, the 100 joules at the beginning need not be
the same 100 joules that are present at the end. What is
conserved is the quantity of act or activity, but the identical act
need not persist through the change. The energy of the form
and act corrupted equals the energy of the form and act educed
but not because of an underlying actuality that persists through
the energy transformation. That is part of the way nature is
ordered. Again, this is not to say that there is no matter that
persists through a change in energy. It is just that whatever that
matter may be, it is not the conserved energy. This seems to be
part of the strangeness of the Law of the Conservation of
Energy that Feynman was trying to describe. It also fits with
Gell-Mann’s treatment of energy as correlative to matter.
However, there is a difficulty with this solution. When
scientists use the Law of the Conservation of Energy, they
typically treat the conserved energy as the sum of the potential
and kinetic energy. For example, a boulder at rest on top of a
cliff has a certain quantity of potential energy with respect to
the ground. As the boulder falls, its potential energy becomes
kinetic energy. Ignoring the effects of the air and any heating,
the sum of the boulder’s potential and kinetic energy remains
the same from its rest on the cliff and throughout its fall.
However, if the potential energy is regarded as a passive
Aristotelian potency and the kinetic energy is regarded as actual
energy, then the energy considered according to the Law of the
Conservation of Energy includes both what is actual and what is

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35

potential. Phenomena such as a swinging pendulum or a roller
coaster especially emphasize the problem. Consider an idealized
roller coaster, one unaffected by the air or by friction with the
rails. When a roller-coaster car is at a peak, its potential energy
is at a maximum and its kinetic energy is zero. As the car drops
to a trough, its potential energy decreases to zero and its kinetic
energy increases to a maximum. As the car then rises up the
track to the peak, the kinetic energy decreases to zero and the
potential energy increases to a maximum. The pattern repeats
over and over. The total energy, the combination of gravitational potential energy and kinetic energy, remains the same
throughout the changes undergone by the car. The conserved
energy is both potential and actual (kinetic). How then can it be
maintained that what is conserved is the quantity of act or
activity?
The physicist Anthony Rizzi gives a plausible solution to this
objection, a solution that preserves the claim that act or activity
is conserved in the Law of the Conservation of Energy:
In summary, conservation of energy preserves overall activity (roughly by
keeping track of the receptivity . . . and overall strength of action) . . . while
conservation of momentum, keeps the net intensity of impetus . . . along any
given line from gradually building in one direction in a line over another. It
also keeps a body from moving arbitrarily.59

Here, consistent with the view for which I am arguing, Rizzi
states that what is conserved is the overall activity. However,
the way in which the conservation of energy does this is in part
by keeping track of receptivity. What might this mean?
Here I want to distinguish between two ways of considering
the energy that a body has in a given location.60 A roller-coaster
car at rest on a peak has gravitational potential energy with
respect to a position that it does not occupy and with respect to
a force of gravity that can move it but has not and by virtue of
work that can be done on it but has not been done. However, I
59

Anthony Rizzi, Physics for Realists (Baton Rouge, La.: IAP Press, 2008), 231.
In making this argument and responding to the objection I have raised, I am
drawing upon McLaughlin, “Act, Potency, and Energy,” 207-43.
60

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THOMAS MCLAUGHLIN

maintain that the car at rest on a peak also possesses actual
gravitational energy in the place it actually occupies considered
with respect to some other place, such as a trough of the track,
in which it is not located and with respect to the force of
gravity. I call the actual gravitational energy that the car has
when located at the peak of the track “classical rest energy” to
distinguish it from gravitational potential energy. It is an actual
gravitational form of energy. This also may be thought of by
considering the work that must be done on the roller-coaster
car to raise it from the bottom of a trough to a peak of the
roller coaster. This work equals the amount of potential energy
that the car has at that height with respect to the trough.61 The
work done in raising the car to its position on the peak might be
thought of as building actual gravitational energy into the car at
its position. I call this “classical rest energy,” by which I mean
the actual (gravitational) energy that a system or a body
possesses in virtue of the actual configuration that the system
has or the actual position that the body occupies when at rest in
a gravitational field or considered with respect to a gravitational
force.
What I am calling classical rest energy is an instance of the
Aristotelian principle of actuality or act. It is the act or activity
of rest, but it is distinct from potential energy. The difference is
that classical rest energy is the energy that the car actually has
where it is located as opposed to the energy it potentially has in
another location. Physicists do not make this distinction because
they are quantitatively the same and because prerelativistic
physics had no notion of rest energy or of a resting activity.
Consequently, when, for example, physicists think of the energy
stored in a system in virtue of its location, they regard it as
actual but still call it potential energy.62 However, quantitative
61

“You will undoubtedly be familiar with another way of interpreting a potential
energy such as U(h) in the last equation. It represents exactly the amount of work that
we would have to do in order to raise an object through a distance h, against the
gravitational pull, without giving it any kinetic energy” (French, Newtonian Mechanics,
378).
62
“The potential energy of a system represents a form of stored energy which can be
fully recovered and converted into kinetic energy” (David Halliday and Robert Resnick,

ENERGY AND FORM

37

equality is not necessarily identity in nature, being, and
intelligibility. A body or system can at the same time possess
actual energy in a position and lack kinetic energy and location
in another position, for they are in different respects. The
roller-coaster car at some height above the Earth’s surface has
both classical rest energy and potential energy, but the two are
distinct. As the car falls and rises, its kinetic energy comes to be
from its potential energy and then passes away into the energy
of its position. The car’s position is both something actual and
something from which the body has potential energy.
Consequently, in tracking the potential energy, the physicist is
also tracking the gain or loss in position and so the gain or loss
in the actual energy of position, what I am calling classical rest
energy. Therefore, since potential energy regarded as receptivity
is quantitatively identical with classical rest energy, the sum of
potential energy and kinetic energy will also give the total
activity, since it is the same as the sum of the classical rest
energy and the kinetic energy. What is conserved is act or
Fundamentals of Physics [New York: John Wiley & Sons, 1970], 113); “We shall call
this stored work the potential energy V” (Uno Ingard and William L. Kraushaar,
Introduction to Mechanics, Matter, and Waves [Reading, Mass: Addison-Wesley Publ.
Co. Inc., 1960], 164); “Every substance has a certain amount of energy stored inside it.
The energy stored in the chemical bonds of a substance is called chemical potential
energy. The kinds of atoms and the arrangement of the atoms in a substance determine
the amount of energy stored in the substance” (Antony C. Wilbraham, Dennis D. Staley,
Michael S. Matta, and Edward L. Waterman, Chemistry [Boston: Pearson Education,
Inc., 2012], 556); “Maxwell’s position appears to be that the word potential applies to
the possibility of acquiring actual energy (KE), whereas today we would maintain that
the word potential pertains to the possibility of delivering energy (e.g., in the form of
KE) already stored in the system” (Eugene Hecht, “An Historico-Critical Account of
Potential Energy: Is PE Really Real?” The Physics Teacher 41 [November 2003]: 488).
“Energy ‘stored’ in this form is called potential energy. The sense of the word is selfexplanatory. By raising the stone we have created a situation which has the potential of
creating motion. Allowing the stone to return to its starting point will convert that
potential to an actual motion. . . . Were gravity the only force that could store energy,
the concept of potential energy would hardly seem worth the effort we have gone
through. Fortunately, there are other forces that can store energy. For example, a spring
or a rubber ball stores energy as it is compressed. . . . There are many other forces that
have this property of storing energy; for each one it is possible to find a formula for the
potential energy, and for each force the formula is different” (March, Physics for Poets,
72, 74-75).

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THOMAS MCLAUGHLIN

activity but the activity is determined partly through calculating
the receptivity of the potential energy, though there is also a
sense in which one can say that the combined potential and
actual (kinetic) energy is conserved. This may or may not be
compatible with what Rizzi had in mind, but it does explain
how the conservation of energy is conservation of activity even
though scientists calculate the conserved energy by determining
the sum of potential and kinetic energy.
Before moving to the last section, I want to acknowledge and
very briefly reflect upon a question that might be raised in
response to my claim that energy is an accident or accidental
form and that what is conserved with respect to the
conservation of energy is the quantity of act or activity.
Someone might be surprised that what is conserved is not
matter, or a substance, or a property such as charge. Feynman
was surprised. This surprise may be especially keen in changes
from one form of energy to a different form, for we might not
expect a particular quantity to be conserved in such accidental
changes or in accidental changes generally. And we might
wonder that the universe has a certain definite and fixed
quantity of energy, a number of energy as it were, even if, as
time passes and because of entropy, less of that energy is
available for work. We might want an account of or reason for
how such is the case. How can it be that what is conserved is
not something like wood or a block that persists through a
change? To put the question hyperbolically, how is it that, on
the understanding of the forms of energy for which I am
arguing, the Law of the Conservation of Energy is not something Pythagorean or like a sort of Leibnizian preestablished
harmony?
Earlier I argued that the Law of Conservation of Energy is a
specified and more determinate application of the more general
principle that the corruption of this is the generation of
something else and vice versa. To this we might add the
explanation offered by Julius Mayer, the codiscoverer of the
Law of the Conservation of Energy: “We complete our thesis,
which necessarily follows from the fundamental principle: causa
aequat effectum and which stands in complete accord with all

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39

natural phenomena.”63 Richard Connell also explains the
conservation of energy in terms of the principle that every agent
must be proportional to its effect:
The first law [of thermodynamics] is only a particular formulation of a general
philosophical principle that says every agent must be proportional to its effect;
or to state the principle in a more traditional way, every agent acts in the
measure of its actuality and cannot act beyond that actuality.64

Combining the proportionality principle of cause and effect and
the principle that the corruption of this is the generation of
something else, the basic idea is that when, for example,
potential energy is actualized into kinetic energy, work is done
on the body moved, which means that a force is exerted, and so
an agency is acting. In doing work, that agency generates a new
form, the kinetic energy, while a previous form, the classical
rest energy, is necessarily corrupted. In the mutual interaction
of bodies, because causes and effects are proportioned
according to the measure of their actuality, the result of the
work done is a gain in kinetic energy, the energy of motion, and
an equal loss of potential energy, the energy of position, for the
body is moved. The loss of position means the corruption of a
corresponding amount of classical rest energy. Energy
interactions show a distinction between mover and moved, and
mover and moved are proportioned so that the effect in the
moved equals the action of the mover. Throughout the
interaction, there are proportionate causes of what comes to be
and passes away.
Furthermore, Aquinas holds that form is a principle of order
and that the form of the universe is its order.65 In the next
63
Julius Robert Mayer, “On the Forces of Inorganic Nature,” trans. R. Bruce
Lindsay, in Energy: Historical Development of the Concept, ed. R. Bruce Lindsay
(Stroudsburg, Penn.: Dowden, Hutchinson, and Ross, Inc., 1975), 282. See also idem,
“The Motions of Organisms and Their Telation to Metabolism,” in ibid., 284-307. See
also Coopersmith, Energy, the Subtle Concept, 336.
64
Connell, Nature’s Causes, 133. For an application of this principle to a different
problem in natural philosophy, but one which also uses energy considerations, see
Benedict M. Ashley, O.P., “Causality and Evolution,” The Thomist 36 (1972): 199-230.
65
See n. 82.

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THOMAS MCLAUGHLIN

section, I shall argue that the Law of the Conservation of
Energy is a formal ordering principle. Thus, the forms of energy
and the Law of the Conservation of Energy are part of the
formal order of the universe, a formal order that is related to
time, for, according to Noether’s theorem, the Law of the
Conservation of Energy follows from the assumption of time
symmetry.66 In addition, as a formal ordering principle, the Law
of the Conservation of Energy would be ordered toward a final
cause. A teleological account of the Principle of Least Action
would partly provide such final causality, for the forms of
energy and the Law of the Conservation of Energy are closely
related to the Principle of Least Action.67 That the universe has
a certain fixed quantity of energy is, perhaps, due to its form
and final cause. Though requiring much more development,
these considerations help us, so to speak, place the forms of
energy and the Law of the Conservation of Energy in the
broader context of the whole universe and indicate a greater
intelligibility in them. Although the category of relation seems
much more important in the universe as understood by
contemporary science than in the cosmos of Aristotle, the Law
of the Conservation of Energy does not reflect a kind of
Leibnizian preestablished harmony. The conservation of energy
is rooted in the natures, essences, powers, and inclinations of
bodies and describes the grasp of broad commonalities among
and across those bodies. The order of energy conservation is in
things themselves and their mutual interactions.
Finally, whatever truth is present in the Pythagorean view of
number, numerical ratios, and the universe, Aquinas holds, in
his own way, that nature employs number as a principle.
However, among the several analogies that Aquinas uses for
understanding the perfection of the universe (house, army, wellordered
household,
and
microcosm/macrocosm),
the
66

See n. 21.
See n. 4 and the following: Jozef Hanc and Edwin F. Taylor, “From Conservation
of Energy to the Principle of Least Action: A Story Line,” American Journal of Physics
72 (2004): 514-21; Jozef Hanc, Edwin F. Taylor, and Slavomir Tuleja, “Variational
Mechanics in One and Two Dimensions,” American Journal of Physics 73 (2005):
603-10.
67

ENERGY AND FORM

41

Pythagorean/Platonic mathematical music/harmony analogy,
which was common in the medieval period, is strikingly
absent.68 Later Thomists have noted Aristotle’s minimal use of
mathematical and experimental techniques in the investigation
of nature.69 We may debate to what extent Aquinas and later
Thomists have in principle successfully captured and
incorporated the insights of Pythagoreanism or of the modern
sciences, but it does not follow that number is the principle of
all things or that mathematics can capture the whole of nature
or that energy and the Law of the Conservation of Energy are
strictly mathematical principles. The interpretation argued for
here, with its robust role for form, avoids that view. Indeed, the
failure to see a strong role for form combined with a no-blocks
view easily leads to a merely mathematical view of energy and
the conservation of energy, but even with Feynman, energy and
the conservation of energy are mysterious and abstract and do
not reflect a Pythagorean/Platonic number realism. The development, working out, and unification of these and other ideas
obviously goes well beyond the scope of this paper and is work
that must be left to future investigations.
IV. THE FORMS OF ENERGY AND THE ORDER OF THE UNIVERSE
The different forms of energy and the Law of the
Conservation of Energy have additional explanatory roles that
also indicate that they are forms in the Aristotelian/Thomistic
sense. Matter and efficient causes, or to use the language of
physics, forces, are insufficient for understanding nature and the
natural order of the universe. Principles that give specificity,
structure, order, and pattern are required as well.70 In Thomistic
68
For analogies that Aquinas uses cosmologically, I am drawing upon Oliva
Blanchette, The Perfection of the Universe according to Aquinas (University Park, Penn.:
The Pennsylvania State University Press, 1992).
69
William A. Wallace, O.P., “The Intelligibility of Nature: A Neo-Aristotelian
View,” The Review of Metaphysics 38 (1984): 33-56.
70
I am drawing upon John Haldane, “A Return to Form in the Philosophy of Mind,”
in Form and Matter: Themes in Contemporary Metaphysics, ed. David S. Oderberg
(Oxford: Blackwell Publishing, 1999), 40-64.

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THOMAS MCLAUGHLIN

natural philosophy, this requirement is met by formal and final
causality. Here I wish only to consider form.
Forms do not provide structure and regularity by acting as
forces, for that would be to confuse formal with efficient
causality. But without formal causes that determine things to be
as they are, efficient causes could not operate in the regular,
systematic, and determinate ways that they do. Efficient
causality originates in things determined and ordered by form
and produces things determined and ordered by form. Likewise,
an actual form of energy is needed to account for a force.
Energy is distinguished from force, for though energy is an
act and is associated with activity, it is not as such a force or
efficient cause. Thus, we distinguish between gravitational force
and gravitational energy, and nuclear forces and nuclear energy.
The distinction between energy and force took centuries to
achieve. Leibniz named what we now call kinetic and potential
energy vis viva and vis mortua respectively. For Humboldt and
others, “force” was the great unifying principle and was used to
describe some things we now know as energy.71 Julius Mayer,
one of the codiscoverers of the Law of the Conservation of
Energy, referred to energy as “force” (Kraft).72 Hermann Von
Helmholtz, in his great 1847 paper on the conservation of
energy (“Über die Erhaltung der Kraft”), also refers to what we
now call energy as Kraft.73 The notion of energy and its forms
developed in response to a conceptual need for something that
is not a force, which implies that energy is not an efficient
cause, and since, as already argued, energy is not a material or
stuff, this supports the claim that the forms of energy are forms.
In support of this claim, we see in the developing distinction
71

See Andrea Wulf, The Invention of Nature: Alexander von Humboldt’s New World
(New York: Alfred A Knopf, 2015).
72
Coopersmith, Energy, the Subtle Concept, 240-45.
73
“From a similar investigation of all the other known physical and chemical
processes, we arrive at the conclusion that Nature as a whole possesses a store of force
which cannot in any way be either increased or diminished. And that, therefore, the
quantity of force in Nature is just as eternal and unalterable as the quantity of matter.
Expressed in this form, I have named the general law ‘The Principle of the Conservation
of Force’” (Hermann Von Helmholtz, “The Conservation of Energy” [1847], in Classics
of Modern Science, ed. William S. Knickerbocker [Boston: Beacon Press, 1927], 286).

ENERGY AND FORM

43

between energy and force the need for a notion of forms that
describes different patterns of activity that must be expressed
according to distinctive formulae.
In physics, energy is often defined as the capacity to do
work. In classical physics, the work done on a body equals the
force applied to it multiplied by the distance over which the
force acts on the body.74 For example, if someone pushes a box
across a floor, the work done depends upon the magnitude of
the force exerted on the box and the distance through which
the force is exerted.75 The box is moved by exerting a force on
it and not by exerting energy on it. Thus, energy and force are
distinguished.76 In doing work, the person moving the box loses
a certain quantity of energy and other forms of energy come to
be.77 The person exerts a force on the box in virtue of the
energy he possesses, and the force communicates or causes a
form of energy in the box and the other things acted upon, such
as the floor. Forms of energy are present, so to speak, on the
origin and delivery end of the force. A person who did not have
the relevant form of energy could not exert a force on the box
and move it. Without the relevant form of energy, we could do
no work. An energy source is needed to bring about physical
change, and the physical change results in a new form of energy
or different amount of energy in the thing acted upon.

74
Mathematically, this is expressed as W = F × x where W equals the work, x equals
the distance over which the force acts on the body, and F equals the force acting on the
body along x.
75
Ohanian, Physics, 1:154-56.
76
The different units in which they are measured further show this distinction. Work
and energy are measured in the same units, whereas force is measured in different units.
For example, in the SI system of units, the unit for energy and work is the joule whereas
the unit of force in the same system of measure is the newton. A joule is a newton
meter, so that the units of energy include the units of force but are not simply the same
as the units of force.
77
The box pushes back and does negative work on the person moving it. In A. P.
French’s analogy, we must pay for what we get.

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THOMAS MCLAUGHLIN

Another example is helpful. A rock on the edge of a cliff has
gravitational energy with respect to the Earth and its gravity.78
When the rock falls from the cliff to the ground, the rock’s
gravitational energy decreases, and the work done by gravity
equals the change in gravitational energy. The efficient cause of
the rock’s fall is the force of gravity and not the gravitational
energy of the Earth/rock system. Nevertheless, the force of gravity
originates in the gravitational energy, especially the mass energy,
of the system, and the force changes the quantity of gravitational
energy, and some gravitational energy is changed into other
forms, such as kinetic energy. Forms of energy are present, so to
speak, on the origin and delivery end of the force in what is a
very ordered and regular process in nature. Further, the system
cannot act gravitationally except insofar as it is in act
gravitationally, and the system is in act gravitationally through
having forms of energy.79 Though we may think that the force
determines the form of energy, on the source side, it is really
the form that determines the force and its uniform and
characteristic operation. The gravitational energy is the wherewithal for doing the work of moving the rock. An analogy with
kinetic energy is helpful. A body in motion, in virtue of its
kinetic energy, exerts a force and does work on another body
that it impacts. A body with kinetic energy that does not act on
something exerts no force and does no work. Kinetic energy is
not a force but can be the source of a force. Likewise, gravitational energy is not itself a force but is the source of a force.
In addition to providing a source for the action of forces and
a result produced by those forces, the form of energy also
provides a pattern or structured order. With respect to the rock
78

Though we typically speak of the rock’s gravitational energy, gravitational energy
belongs to the rock and the Earth together. It depends upon the configuration of the
system. See Ohanian, Physics, 1:164-65.
79
“Energy of any sort generates gravitational fields and is in turn acted on by
gravitational fields” (Steven Weinberg, Dreams of a Final Theory [New York: Vintage
Books, 1992], 225). “Now the question is, is it [energy] the source of the field? The
answer is yes. Einstein understood gravitation as being generated by energy. Energy and
mass are equivalent, and so Newton’s interpretation that the mass is what produces
gravity has been modified to the statement that the energy produces the gravity”
(Feynman, Character of Physical Law, 77).

ENERGY AND FORM

45

on the top of a cliff, a varying continuum of gravitational
energy is present from the top of the cliff to the ground. This
ordered structure or pattern is more evident if we think of the
whole solar system in which the Sun largely defines a gravitational potential with planets and various minor bodies
embedded within and having their own gravitational potentials.80 This gravitational energy structure or pattern is often
modeled by a gravity well in which the Sun’s gravitational
potential is represented by a large funnel and those for the
planets and other bodies are represented by spikes within the
larger funnel. Gravity wells are a commonplace in textbooks
and in science museums.81 We speak of using a certain amount
of energy to escape such wells.
For Aristotle and Aquinas, to a considerable extent the
orderly arrangement of the world is itself characterized by and
follows from form.82 The forms of energy function according to
80
Every massive body makes a gravitational potential around it. The gravitational
potential is the potential energy per unit mass. Joules per kilogram is a typical unit of
measure. In Newtonian physics, the gravitational potential VG(r) equals -GM/r where G
is the universal constant of gravitation, M is the mass of the body generating the
potential, and r equals the distance from the origin, usually the center of the body
generating the potential. The addition of a further massive body m yields the general
Newtonian expression for gravitational potential energy -GMm/r.
81
Willem H. van den Berg, “The Gravitational Landscape of the Solar System,” The
Physics Teacher 46 (2008): 363-64.
82
“Whoever possesses some form is related through that form to things in reality.
For example, white wood is through its whiteness like some things and unlike other
things” (ScG I, c.72). All English quotations from Aquinas’s Summa contra gentiles I are
from Thomas Aquinas, Summa contra gentiles, book 1, trans. Anton C. Pegis (Notre
Dame, Ind.: University of Notre Dame Press, 1991). The importance of form in the
order of the universe is also evident in the Aristotelian notion of natural place. The
sublunar bodies themselves are not indifferently related to place but are ordered by their
forms to a particular place or region in the universe that is proper to their natures. The
least formal and most material element (earth) is ordered to the center of the universe
and the most formal and least material element (fire) to the extremity of the universe.
The bodies of the noblest natures occupy the outermost places in the universe, and the
bodies of the least noble natures occupy the central position. See IV Phys., lect. 6
(Blackwell, Spath, and Thirlkel, trans., 468-69 and 492-93) and I De Caelo, lect. 18
(Marietti ed., 181-82). My point concerns Aquinas’s general view of the importance of
form in the order of nature, which is distinct from the largely mistaken specific physics
and cosmology that he held. I am not defending the four-element theory or Aristotle’s

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THOMAS MCLAUGHLIN

this explanatory requirement. In contemporary scientific
accounts of the world, we see this in the remarkable natural
order known through the different forms of energy and the laws
governing them. In general, “conservation laws . . . represent
one of the physicist’s most powerful tools for organizing his
description of nature.”83 This is especially the case for the Law
of the Conservation of Energy. The Law of the Conservation of
Energy, although it does not determine the way everything is in
the universe, is an ordering principle that, as far as we know,
applies to all the things in the universe. Not only is it the case
that whenever energy is lost by a body or a physical system that
something else gains an equal amount of energy, but also the
Law of the Conservation of Energy involves the order of all the
different forms of energy to each other. This includes and goes
considerably beyond the already far-reaching order in the
universe recognized through the common notion of mass. As
discussed previously, each of the different forms of energy has
its own determinate character, formula, and pattern of activity
that distinguishes it from other forms of energy. These different
forms of energy are themselves related to each other in very
definite ways, and changes in the forms of energy occur in a
very definite order. We exploit these relations to generate forms
of energy that are useful to us, such as electricity, from other
forms that are not so useful, such as running water or wind
turbines. In a very profound and far-reaching way, the world is
governed, so to speak, according to the Law of the
Conservation of Energy.

specific view of natural place. Further, in a multiplicity of things ordered together into a
totality, the form of the whole is their order: “Now the form of any whole which is one
through the arrangement of its parts is the order of that whole” (XII Metaphys., lect. 12
[Marietti ed., 2627]; English translation from Thomas Aquinas, Commentary on the
Metaphysics of Aristotle, trans. John P. Rowan [Chicago: Henry Regnery, 1961]).
Aquinas uses the examples of an army, a household, a city, or a commonwealth: “For
sometimes things are united merely by their arrangement, as the men in an army or the
houses in a city; and then the whole has the role of a form which is designated by the
term army or city” (V Metaphys., lect. 3 [Marietti ed., 779]). Indeed, for Aquinas, the
form of the universe is its order. See XII Metaphys., lect. 12.
83
French, Newtonian Physics, 368.

ENERGY AND FORM

47

This is not essentially an order of material or efficient causes
but an order of forms of energy. For some kinds of problems,
especially those in atomic physics, physical interactions are
more easily and usefully analyzed by measuring the forms and
quantities of energy and ignoring the forces involved, especially
if measuring the forces is extremely difficult or impossible.
These interactions can be treated as changes in a formal order
of energy. More significantly, the order shown by the Law of
the Conservation of Energy is useful not only for its predictive
and retrodictive power but also as an instrument of discovery.
Apparent failures in the law reveal gaps in our understanding of
the order of nature. This sometimes results in striking discoveries, as in the case of the neutrino.84 New forms of energy
have also been discovered in this way.85 In other cases, as in the
case of the Sun and of other stars, a recently discovered form of
energy explains the energy source of something in nature.86 The
discovery of nuclear energy finally led to the discovery of the
Sun’s energy source.87 More recently, from the discovery that
the expansion rate of the universe has been increasing, the
existence of something called dark energy has been inferred as
an explanation.88 Although the Law of the Conservation of
84

“In fact, we would sooner invent new forms of energy than sacrifice the law of the
conservation of energy. This is exactly what did happen in 1930. Wolfgang Pauli (19001958) was troubled by the problem with the ß͟-decay spectrum, and . . . invented a new
particle, the neutrino, as ‘a desperate remedy to save . . . the law of conservation of
energy’” (Coopersmith, Energy, the Subtle Concept, 336).
85
“And whenever a situation has arisen in which it seemed that energy had
disappeared, it has always been possible to recognize and define a new form of energy
that permits us to save the conservation law” (French, Newtonian Physics, 368). “The
inquiry into the various manifestations of energy is a powerful way of analyzing systems
according to the fundamental law of energy conservation. On rare occasions, physicists
propose revolutionary new fundamental forms of energy when the principle of energy
conservation seems violated while using only the currently agreed upon energy forms”
(Harrer, “On the Origin of Energy,” 458).
86
George O. Abell, Exploration of the Universe, 3rd ed. (New York: Holt, Rinehart,
and Winston, 1975), 545-47.
87
“The discovery that some of the energy locked up in the nuclei of atoms is
released in the interiors of stars is perhaps the most significant contribution of
astronomy in the twentieth century” (Abell, Exploration of the Universe, 547).
88
Richard Panek, The 4% Percent Universe (New York: Mariner Books, 2011).

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THOMAS MCLAUGHLIN

Energy does not determine the places of the different natures of
things in the same way as does form in the Aristotelian theory
of natural places, it nevertheless enables us to deepen our
understanding of the natural order and fill in gaps in what we
know of that order as we come to know ever more diverse
natural phenomena as different kinds of energy. We discover an
ever-deepening and ever-more-general pattern, and the Law of
the Conservation of Energy and the forms of energy are
principles of the pattern.
Through the different forms of energy, their interrelations,
and the Law of the Conservation Energy, we grasp a profound
and pervasive unity throughout the universe. In providing a
quantitative relation between very different and seemingly
unrelated kinds of things, the Law of the Conservation of
Energy has a profoundly unitive and ordering role in nature.
Cosmologically, dark energy increases the expansion rate of the
universe as a whole. The overall behavior of the whole universe
follows the Second Law of Thermodynamics. As the universe
expands and its contents interact, the “flow” of energy is from a
low-entropy state to a higher-entropy state. We see a pattern
even in the growing disorder of the universe.89 The forms of
energy and the Law of the Conservation of Energy manifest a
formal order in nature.
I shall end with an example that briefly sketches an order of
different forms of energy. The example begins with the Sun.90
Except for nuclear, geothermal, and the larger portion of tidal
energy, most of the energy we use ultimately comes from the

89

Lightman, Great Ideas in Physics, 59-115. See also John W. Keck, “The Natural
Motion of Matter in Newtonian and Post-Newtonian Physics, The Thomist 71 (2007):
529-54.
90
“We mention that the large difference in temperature between the sun and space
plays a vital role in keeping us alive. . . . But the second law decrees that our bodies, or
any machines, must inevitably run out of usable energy if isolated. To stay alive we must
get a constant infusion of energy at high temperatures and release our wasted body heat
into something cold. The cold-temperature heat sink is space. The high-temperature
heat source can be traced to our food and then to the sun. . . . Either directly or
indirectly, the sun keeps us alive. If the sun were the same temperature as space, our
body-machines would grind to a halt” (Lightman, Great Ideas in Physics, 98).

ENERGY AND FORM

49

Sun.91 As the Sun came to be, some of its gravitational potential
energy was converted to nuclear energy in its core, where the
Sun is a kind of fusion reactor. As in the case of other stars,
nuclear reactions in the Sun’s core produce thermal and radiant
energy. The Earth receives some of the Sun’s radiant energy, a
portion of which becomes thermal energy and thereby heats the
Earth’s atmosphere and surface and drives much of the Earth’s
winds, atmospheric circulation, evaporation and precipitation,
ocean waves, and other phenomena, some of which we use as
sources of energy. Since radiant energy from the Sun drives the
water cycle, it is also a source of hydroelectricity.92 By photosynthesis, plants convert the Sun’s radiant energy into another
form of energy, ATP, and use the Sun’s energy to make cells
from carbon dioxide, water, and various minerals. Humans and
animals eat plants, which then provide thermal, chemical, and
mechanical energy. Waste products from humans and other
animals provide sources of energy for other living things. Some
plants are burned, and their chemical energy is converted into
heat. By various other processes, the energy stored in plants
becomes the forms of energy we find in various fossil fuels, such
as oil, natural gas, and coal.93
Similarly, the Sun’s gravitational potential energy can be
traced backward in an orderly way to the Big Bang and so
provide both stability and orderly change through the various
forms of energy: from the Big Bang, to heating the planet, to
walking across a street. The forms of energy and the energy
transformation processes are more complex than is described
here, but the description given is sufficient to indicate that the
forms of energy provide a pattern and a stable, intelligible order
91

“The entire enterprise of your existence—using energy to turn food into more you
and more descendants—draws on the bank of low-entropy radiation streaming from the
Sun. Some source of low entropy is needed for any activity in the Universe, including
life” (Lewis and Barnes, Fortunate Universe, 101-2).
92
Michael E. Wysession, course guidebook to The Science of Energy, The Great
Courses (Chantilly, Va.: The Teaching Company, 2016), 114.
93
See Vaclav Smil, Energies (Cambridge, Mass.: MIT Press, 1999), xiii; Martin
Goldstein and Inge F. Goldstein, The Refrigerator and the Universe (Cambridge, Mass.:
Harvard University Press, 1993), 4-5, 56-57; Lewis and Barnes, Fortunate Universe,
100-108.

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THOMAS MCLAUGHLIN

as well as sources for the action of forces and the forms of
energy that are produced by those forces. This order not only
includes the interrelations of the different forms of energy but
covers an extraordinary scale—from the Big Bang and the
whole universe, to a child eating lunch, to subatomic particles—
all of which happens according to the conservation of energy.94
This unified order is an order not of forces but of forms, forms
that determine things to be as they are and determine forces to
operate in the regular, systematic, and determinate ways that
they do. We see here how the forms of energy function in
nature in ways that indicate that they are Aristotelian forms.
SUMMARY
I have argued that the different forms of energy are specific
instances of form in the Aristotelian or Thomistic sense. “Forms
of energy” most commonly refers to the different kinds or
species of energy, but it also means or implies that the forms of
energy are accidental forms in things by which things have
certain kinds and quantities of energy. My argument focused on
the Law of the Conservation of Energy and the discussions of
energy by several physicists, especially Richard Feynman. Each
of the many different forms of energy has its own determinate
character, pattern of activity, and formula by which it is known
and distinguished from other forms of energy and in this way
fits both the Aristotelian notion of form as kind or species and
as a principle of the species from which distinctive operation
follows. From Feynman’s key claim that energy is not a thing or
an underlying stuff, I argued that the various forms of energy,
like form in the Aristotelian/Thomistic sense, are not things but
principles of things. The forms of energy are accidents and are
that by which something has energy, which indicates that the
94

“Throughout the transformations that take place, the bookkeeping goes on:
kilowatt-hour for kilowatt-hour, all the energy can be accounted for. The total amount
remains the same regardless of the changes of form. According to the first law, the total
energy of the universe will remain the same for all time, the same as it is today, and the
same as it was in the distant past. Forward and backward, it makes no difference”
(Goldstein and Goldstein, Refrigerator and the Universe, 4-5).

ENERGY AND FORM

51

form of energy is an accidental formal cause and that when
something acquires or loses a form and quantity of energy, such
changes are actualizations of a potency and are the gain or loss
of forms in an Aristotelian sense. I then argued against Heisenberg’s claim that energy is prime matter. I maintained that
energy is identified with activity, but is not a force, which
supports the claim that the forms of energy are forms in the
Aristotelian sense, since form is an act and things act insofar as
they are in act, something that is characteristic of energy in its
different forms. Finally, I argued that the Law of the Conservation of Energy and the forms of energy indicate a formal
order in nature and thereby help provide the requirement for
formal causality in nature where material and efficient causes
are insufficient for explaining the natural world and its order.
Thus, through the scientific notion of the forms of energy, the
Aristotelian/Thomistic notion of form is present in the modern
scientific understanding of nature. Future work could involve
further investigations of energy and the principles of act,
potency, form, matter, and end.95

95

Earlier versions of this paper were read at the ACPA (2013), the Symposium
Thomisticum (2016), and The American Maritain Association (2018). I wish to thank
the participants of those conferences for their questions and comments. I would also like
to express my gratitude to many colleagues who helped me with this paper, especially
John Brungardt, Chris Blum, Carl Vater, Michael Gundzik, John Keck, Timothy Kearns,
Alphonso Pinto, Fr. Andreas Hoeck, Fran O’Rourke, and Ed Houser.

The Thomist 86 (2022): 53-89

SAINT THOMAS AQUINAS ON THE INCOMPLETENESS
OF THE HUMAN SOUL
KENDALL A. FISHER
Seattle University
Seattle, Washington

S

AINT THOMAS Aquinas’s metaphysical account of the
human soul and its hylomorphic union with the body has
long been lauded as a way to avoid substance dualism
while affirming the immortality of the soul. Aquinas maintains
that the human soul is an immaterial subsistent part of the
human being that survives the death of the person.1 It owes its
metaphysical status to its role as the intellective principle in the
human being. During life, it serves as the seat of our intellective
acts, and even in its postmortem, separated state it continues to
carry out intellective operations.2 Yet despite this existential and
operational independence from the body, Aquinas argues that
soul and body are not two substances accidentally united. The
human being is not an aggregate or accidental unity.3 Instead,
he maintains that the soul is the substantial form of the body
and argues that the hylomorphic unity this provides renders the
human being a single, unqualifiedly unified substance, that is, a
substantial unity.4
1

For the soul’s immateriality and subsistence, see STh I, q. 75, a. 2. For its
incorruptibility and postmortem existence, see STh I, q. 75, a. 6.
2
STh I, q. 75, a. 2; Q. D. De Anima, a. 1, a. 14; STh I, q. 77, a. 8.
3
STh I, q. 76, a. 1.
4
For further discussion of Aquinas’s hylomorphic account of the human being see
Donald C. Abel, “Intellectual Substance as Form of the Body in Aquinas,” Proceedings of

53

54

KENDALL A. FISHER

For as long as it has been lauded, however, Aquinas’s view
has also been plagued with charges of incoherence. A thing that
can exist and operate apart from a larger whole—a thing like
the human soul—seems paradigmatic of a complete substance,
and in Aquinas’s metaphysics no complete substance can be
united to anything further to form a substantial unity. Thus, the
soul’s existential and operational independence from the body
generates, at the very least, a prima facie tension with the
human being’s substantial unity.5 But if Aquinas is not philo-

the American Catholic Philosophical Association 69 (1995): 227-36; B. C. Bazan, “The
Human Soul: Form and Substance? Thomas Aquinas’s Critique of Eclectic
Aristotelianism,” Archives d’histoire doctrinale et littéraire du moyen-âge 64 (1997): 95126; J. E. Brower, Aquinas’s Ontology of the Material World: Change, Hylomorphism,
and Material Objects (Oxford: Oxford University Press, 2014); C. Brown, Aquinas and
the Ship of Theseus: Solving Puzzles about Material Objects (New York: Continuum,
2005); Gregory Coulter, “Aquinas on the Identity of Mind and Substantial Form,”
Proceedings of the American Catholic Philosophical Association 64 (1991): 161-79; J.
Eberl, “Aquinas on the Nature of Human Beings,” The Review of Metaphysics 58
(2004): 333-65; idem, “Varieties of Dualism,” International Philosophical Quarterly 50
(2010): 39-56; G. Klima, “Man=Body+Soul: Aquinas’s Arithmetic of Human Nature,”
in Thomas Aquinas: Contemporary Philosophical Perspectives, ed. B. Davies (Oxford:
Oxford University Press, 2002): 257-74; idem, “Thomistic ‘Monism’ vs. Cartesian
‘Dualism,’” Logical Analysis and History of Philosophy 10 (2007): 92-112; idem,
“Aquinas on the Materiality of the Human Soul and the Immateriality of the Human
Intellect,” Philosophical Investigations 32 (2009): 163-82; idem, “Aquinas on the Union
of Body and Soul” Quaestiones Disputatae, special issue on Hylomorphism: Ancient,
Medieval, and Contemporary Approaches 10 (2020): 31-52; Robert Pasnau, Thomas
Aquinas on Human Nature: A Philosophical Study of Summa Theologiae, 1a 75-89
(Cambridge: Cambridge University Press, 2002); Eleonore Stump, “Non-Cartesian
Substance Dualism and Materialism Without Reductionism,” Faith and Philosophy 12
(1995): 505-31; idem, Aquinas (London and New York: Routledge, 2003).
5
Other concerns regarding the coherence of Aquinas’s account have been raised as
well. Gregory Coulter argues that substantial form must have an inherent kind of
existential incompleteness which allows for its union with matter and that this
incompleteness is inconsistent with subsistence (Coulter, “Aquinas on the Identity of
Mind and Substantial Form”). See Klima, “Aquinas on the Materiality of the Human
Soul,” for a response to this kind of concern regarding the compatibility of the
inherence and subsistence of the soul.

INCOMPLETENESS OF THE HUMAN SOUL

55

sophically entitled to the substantial unity of the human being,
his view inevitably collapses into the dualism he seeks to avoid.6
Aquinas recognizes the tension between the soul’s independence and its union with the body but attempts to dissolve that
tension by blocking any inference from the soul’s capacity for
separate existence and operation to its completeness as a substance. He argues that the soul ultimately fails to be a complete
substance because it is not complete in a specific nature.7
Human nature is only complete when the soul is united to
matter to constitute the human body. But to a critic this may
appear simply to beg the question. Presumably a thing that
exists and operates on its own ought to count as specifically
complete—perhaps not in human nature, but in some intellective nature of its own. In that case, the soul ought to count as
a complete substance. Aquinas’s claim seems ad hoc. Worse still,
it seems to conflict with his broader metaphysical framework in
which a thing’s existence and its species membership derive
from the same source.8
Aquinas has more to say in his defence. In particular, he
provides two accounts meant to motivate the claim that the soul
is specifically incomplete. In the first and more prominent of
these, found in the disputed question De anima, he appeals to
the soul’s dependence on the body for its intellective operation
as a marker of its specific incompleteness. During life, the soul
relies on images stored in the brain to produce the intelligible
forms through which it understands. Aquinas argues that a thing
cannot be complete in a specific nature if it lacks within itself
6

See STh I, q. 76, a. 1 for Aquinas’s rejection of substance-dualist views. For
comparison of Aquinas’s hylomorphic account with dualist accounts see Richard Cross,
“Aquinas and the Mind-Body Problem,” in Mind, Metaphysics, and Value in the
Thomistic and Analytic Traditions, ed. J. Haldane (Notre Dame, Ind.: University of
Notre Dame Press, 2002), 36-53; Eberl, “Varieties of Dualism”; idem, “Aquinas on the
Nature of Human Beings”; Klima, “Thomistic ‘Monism’ vs. Cartesian ‘Dualism’”;
Stump, Aquinas; idem, “Non-Cartesian Substance Dualism”; Van Dyke, “Not Properly a
Person.”
7
See, for instance, Q. D. De Anima, a. 1, ad 1 and ad 4; Q. D. De Anima, a. 14, ad
21.
8
For further detail, see below.

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KENDALL A. FISHER

those things required for its essential and natural operations.
Because the soul depends on the body for these images, on its
own it lacks the means of producing the intelligible forms
required for its natural and optimal mode of intellective understanding. It is, therefore, specifically incomplete.9
In a second account, from the disputed question De spiritualibus creaturis, Aquinas argues that the soul is incomplete
because, on its own, it cannot fully express what it contains
virtually, qua form. There are things of which it is the principle
that cannot be realized apart from its union with matter to
constitute the body—for instance, the sensitive and nutritive
powers, which can only be realized in the body. Aquinas
maintains that a thing cannot be complete in a specific nature
unless it expresses that which it contains virtually. The fact that
many of the powers rooted in the soul virtually cannot be
realized through the soul’s subsistence alone reflects the fact
that it is, considered apart from its union with matter to
constitute the body, specifically incomplete.10
In this article, I examine whether either of these accounts
provides a compelling case for the soul’s specific incompleteness. I argue that while the first appeals to considerations central to Aquinas’s account of human nature, his characterization
of the nature of the dependence of soul on body for its
intellective operation ultimately undermines his claim that such
a dependence renders the soul specifically incomplete. He characterizes the dependence as dependence on an object, but when
one thing depends on another as an object in a given operation
we do not typically think of the dependee as something without
which the dependent is specifically incomplete.
Nevertheless, I contend that the second account, namely,
that the soul fails to express those things of which it is the
principle, is more promising. Although the soul does not depend on matter for its existence, it does depend on matter for
9

Q. D. De Anima, a. 1.
See De Spir. Creat., a. 2.

10

INCOMPLETENESS OF THE HUMAN SOUL

57

the full realization of its formal character as the substantial form
of the human being. This provides the theoretical resources for
a principled account of how and why the soul fails to be
specifically complete—and one that remains consistent with
Aquinas’s broader metaphysical framework.11
The article has five sections. In (I) I present Aquinas’s
hylomorphic ontology and situate the human soul within it.
This is important for understanding the soul’s peculiar status in
his metaphysical system. In (II) I explain how the tension
between the soul’s independence and its substantial union with
the body arises. In (III) I consider Aquinas’s first account of the
soul’s specific incompleteness, namely, that it depends on the
body for its intellective operations and argue that such an
account is inadequate for establishing the soul as specifically
incomplete. In (IV) I present his second account, namely, that
the soul cannot express or realize all those things of which it is a
principle when separated from matter. I contend that this
explanation can provide the theoretical resources to secure his
11
Recently, Daniel De Haan and Brandon Dahm have argued that the separated soul
(what they refer to technically as the anima separata, which includes the rational soul—
i.e., the soul insofar as it is the human substantial form, along with the esse in which it
subsists, its individuating features, and the accidents and powers which it substands)
ought to count as an incomplete person. See D. D. De Haan and B. Dahm, “Thomas
Aquinas on Separated Souls as Incomplete Human Persons,” The Thomist 83 (2019):
589-637; D. D. De Haan and B. Dahm, “After Survivalism and Corruptionism:
Separated Souls as Incomplete Persons,” Quaestiones Disputatae, special issue on
Hylomorphism: Ancient, Medieval, and Contemporary Approaches, 10 (2020): 161-76.
In many ways our projects are complementary and largely compatible (though our
terminology sometimes differs). They are, nevertheless, distinct. De Haan and Dahm
seek to emphasize just how complete (existentially, operationally, formally, etc.) and just
how person-like the anima separata turns out to be for Aquinas—even if it fails,
categorically speaking, to count as a person because of its specific incompleteness. They
argue that, despite failing to be specifically complete, the anima separata nevertheless
achieves four other kinds of completeness and in addition satisfies, to a significant
degree, two other criteria for personhood. Given this, they contend that the anima
separata ought to count as an incomplete person (even if it does not count categorically
as a person, because it fails to be specifically complete). By contrast, my aim is to
elucidate how and why Aquinas is entitled to maintain that the separated soul is
specifically incomplete, despite the fact that it is, after all, complete in so many other
significant ways (e.g., existentially and operationally).

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KENDALL A. FISHER

commitment to the soul’s separate existence and its unqualified
union with the body. Lastly, in (V) I consider how the account
offered in (IV) can be squared with the metaphysical principles
of Aquinas’s system.
I
Aquinas endorses a broadly Aristotelian hylomorphic ontology. In his view, material substances are composites of a
principle of actuality (substantial form) and a principle of
potency (prime matter). For Aquinas, prime matter is pure
potency with no actuality in its own right.12 But through their
union as actualized potency, substantial form and prime matter
constitute the substance.
Aquinas maintains that substantial form, as the actuality of a
material composite, is a principle of existence. In his view, all
created substances participate in being, esse.13 But the esse they
receive is limited and contracted according to their specific
natures.14 Substantial form is the principle by which created substances have esse. It is their quo est. In material substances, it
communicates that esse to matter in the constitution of the
substance. But while the form is that by which the composite
exists (quo est), it is not, generally speaking, the subject of being
or that which is (quod est).15 That which is, is the form-matter
composite. The composite is the subject of being, which has esse
in its own right. For this reason, the composite is said to subsist
or exist per se, but generally speaking, the form is not.16

12

De Princ. Natur., c. 2.
De Spir. Creat., a. 1.
14
Ibid.
15
ScG II, c. 54; De Pot., q. 3, a. 8. The human soul is an exception. See discussion
below.
16
For Aquinas’s use of the terms “subsist” and “exist per se,” see, IV Metaphys.,
lect. 1; De Pot., q. 9, a. 1; STh I, q. 29, a. 2.
13

INCOMPLETENESS OF THE HUMAN SOUL

59

Aquinas’s hylomorphism is distinctive because he believes
that every substance has exactly one substantial form.17 (This is
known as the doctrine of the unity of substantial form.18) In
material substances, substantial form is the first form united
directly to prime matter and it accounts for the existence
simpliciter of the material composite, the substance.19 Since only
one form can be the first form, only one form can be a
substantial form. Thus, an animal is not three-dimensionally
extended by means of one form, living by means of another,
and sensitive by means of a further substantial form. Instead,
numerically the same form accounts for the substance existing at
all and for its existing as a particular species member in the
category of substance.20 All subsequent forms are accidental.
This doctrine also entails that while material substances may
have many integral parts (hands, eyes, hearts, limbs, etc.) all of
these exist by means of one and the same substantial form.
Substantial form, as the first form, takes us from the pure
potency of prime matter to an actually existing substance. It is
the actuality, therefore, of the whole and of any and all parts
that the whole comprises.21 This has two significant ramifications. First, whole substances are ontologically prior to their
parts. In other words, a substance’s parts (e.g., my hands, or
heart, or eyes) do not exist by means of their own unique esse
brought to them by their own unique substantial forms. Instead,
they receive esse insofar as they are parts of the whole which
17

Q. D. De Anima, a. 9.
II De Anima, lect. 1; STh I, q. 76, a. 4; Q. D. De Anima, a. 9. For discussion of the
debate concerning the unity vs. plurality of substantial forms see Robert Pasnau,
Metaphysical Themes 1274–1671 (Oxford: Clarendon Press, 2011), 574-96; J. Wippel,
“Thomas Aquinas and the Unity of Substantial Form,” in Philosophy and Theology in
the Long Middle Ages, ed. K. Emery, R. Friedman, A. Speer (Leiden: Brill, 2011),
117-54; Emily Michael, “Averroes and the Plurality of Forms,” Franciscan Studies 52
(1992): 155-82; Daniel A. Callus, “The Origins of the Problem of the Unity of Form,”
The Thomist 24 (1964): 257-85.
19
STh I, q. 76, a. 4; De Spir. Creat., a. 3; Q. D. De Anima, a. 9.
20
De Ente, c. 1; ScG III, c. 7; De Spir. Creat., a. 1, ad 24; STh I, q. 5, a. 5; Q. D. De
Anima, a. 1, ad 12.
21
Q. D. De Anima, a.10; STh I, q. 76, a. 8.
18

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KENDALL A. FISHER

receives esse.22 Whole substances are, thus, the proper subjects
of esse. And yet the integral parts of a substance are, in some
sense, subjects of esse, too, though in a qualified way.23 They
have esse by means of substantial form, but that substantial form
(and the esse which they possess) is not uniquely their own.
Aquinas recognizes such parts, as subjects of esse, as
ontologically distinct from accidental or material forms. The
latter are not subjects of esse in any sense, but only principles by
which a composite has esse. For this reason, Aquinas considers
parts like the hands, eyes, heart, and so on, to be subsistent in
some sense.24 Although they are incomplete substantial parts
they are still, in some sense, subjects of esse. This means that
they have esse per se, that is, that they subsist.25 Nevertheless,
Aquinas reserves the strict notion of subsistence or existence per
se for that which is a subject of esse and complete in a specific
nature. Incomplete subsistent parts are just that: incomplete.
The second ramification of the doctrine of the unicity of
substantial form is that it renders substantial form the principle
of substantial unity in a substance as well as a principle of being.
A whole is unified by its single substantial act of existence,
communicated to the whole (and thus any parts comprised by
the whole) by a single substantial form.26 Anything that exists by
22

Q. D. De Anima, a.10; STh I, q. 76, a. 8.
STh I, q. 75, a. 2, ad 1 and 2.
24
See ibid.; Q. D. De Anima, aa. 1 and 14. For Aquinas, subsistence does not, on its
own, imply the capacity for separate existence. The soul owes its capacity for existence
apart from the human substance as a whole to both its subsistence and its status as
substantial form (STh I, q. 75, a. 6; Q. D. De Anima, a. 14). For further discussion of
the nature of subsistence in Aquinas’s metaphysics, including his characterization of
parts like the hand or eye as subsistent, see Kendall A. Fisher, “Operation and Actuality
in St. Thomas Aquinas's Argument for the Subsistence of the Rational Soul,” The
Thomist 83 (2019): 185-211; idem, “Saint Thomas Aquinas and the Too-ManyThinkers Problem,” Quaestiones Disputatae, special issue on Hylomorphism: Ancient,
Medieval, and Contemporary Approaches, 10 (2020): 106-24; Pasnau, Thomas Aquinas
on Human Nature, 48-57.
25
For further discussion of the identification of that which has esse per se and that
which is a subject of esse, see Fisher, “Operation and Actuality.”
26
Q. D. De Anima, a. 10; STh I, q. 76, a. 8.
23

INCOMPLETENESS OF THE HUMAN SOUL

61

means of the same substantial form is unified into a single
substance. Anything, however, that exists by means of multiple
forms (substantial or accidental) will be at most an accidental
unity or an aggregate.27 In this way, substantial form accounts
for the existence of a substance as well as its unity.
From the foregoing discussions we can see that, for Aquinas,
substantial form is the principle by which the esse received by
the form-matter composite is determined to a specific substantial nature. Indeed, all forms, substantial and accidental alike,
determine matter or their subject to exist in a particular kind of
way. Substantial form takes us from pure potency to an individual in the category of substance. There is, then, something
about form that is responsible for this determination. I will call
this its formal character. Substantial form determines a substance to a specific substantial nature in accordance with its
formal character. Accidental forms qualify, quantify, and relate
their subjects in accordance with their formal characters. When
substantial form and prime matter are united as actualized
potency, the substantial form’s formal character is realized in
the matter.
Aquinas’s ontology includes created immaterial substances as
well as material ones. These immaterial substances, which he
identifies with the angels, are subsistent forms. Like material
substantial forms, subsistent forms are principles of esse and, as
such, they determine esse to a specific nature in accordance with
their formal characters.28 But instead of communicating that
esse to matter to constitute a material substance, they receive it
in their own right.29 They themselves are the subjects of the
being of which they are also principles,30 and their formal
characters are completely realized in their own immaterial
subsistence (rather than in matter). Immaterial substances are, in
27
For further discussion, see discussion of substantial unity in Pasnau, Thomas
Aquinas on Human Nature, 78-88.
28
De Spir. Creat., a. 1.
29
STh I, q. 50, a. 2, ad 3.
30
Q. D. De Anima, a. 1; STh I, q. 75, a. 2; De Spir. Creat., a.1. Such substances are
not identical with their esse, however. That is true only of God (ScG I, c. 22).

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KENDALL A. FISHER

Aquinas’s view, intellective beings.31 Thus, like material
substances, they can and do serve as the subjects of further
forms and powers (e.g., intellective and volitional powers, intelligible species).32 These further forms are, however, accidental
rather than substantial.33 Like created material substances,
created immaterial substances have just one form that accounts
for their existence simpliciter and determines them to their
specific nature.
The human soul is a hybrid of sorts between a material
substantial form and an immaterial substance, in Aquinas’s view.
Like a material substantial form, it communicates esse to matter
as a hylomorphic actuality—in this case, to constitute the
human body.34 But the soul is more than the actuality of the
human body. Following Aristotle, Aquinas holds that intellective cognition must take place in an immaterial subject.35 No
part of the body (the soul-matter composite), therefore, can
serve as the intellective faculty. Instead, Aquinas locates the
31

STh I, q. 50, a. 1.
For Aquinas, a power is a formal principle by which its subject operates.
Immaterial substances can support such accidents because their natures are subjects of
esse, and thus potencies for esse. This affords them a principle of potency that can be
actualized by further forms (STh I, q. 54, a. 3, ad 2).
33
In an important sense, Aquinas considers all subsequent powers and forms, even
those that follow directly from the essential nature of a thing, accidental. This is not
because they are necessarily all unrelated to the thing’s essential nature (though some
may well be). Rather it is because anything beyond the first form, which accounts for a
thing’s existence simpliciter, is accidental rather than substantial in Aquinas’s
metaphysical framework (STh I, q. 76, a. 4). Aquinas calls those accidents that flow
from a thing’s specific nature, “propria,” to distinguish them from accidents that do not
(STh I, q. 77, a. 1, ad 5; Q. D. De Anima, a. 12, ad 7). See below for further discussion
of the powers of the soul.
34
De Spir. Creat., a. 2; STh I, q. 76, a. 1.
35
STh I, q. 75, a. 2; Q. D. De Anima, aa. 1 and 14. For discussion of Aquinas’s
argument for the incorporeity of the intellect, see D. R. Foster, “Aquinas on the
Immateriality of the Intellect,” The Thomist 55 (1991): 415-38; David P. Lang,
“Aquinas’s Impediment Argument for the Spirituality of the Human Intellect,” Medieval
Philosophy and Theology 11 (2003): 107-24; Pasnau, Thomas Aquinas on Human
Nature, 48-57.
32

INCOMPLETENESS OF THE HUMAN SOUL

63

intellect in the soul alone, apart from matter. This requires that
the soul be the sort of thing that can serve as the seat of intellective operations, which, in short, requires that it be a subsistent part of the human being as well as her substantial form.36
This combination gives the human soul a peculiar ontological
status. The substantial forms of all other material composites
are principles by which the composite exists, but they are not
subjects of being. As a subsistent part of the human being,
however, the soul is. It exists per se.37 This means that the soul
is both a principle of esse and a subject of that esse.38 In this
respect, it is akin to an immaterial substance. Yet the soul is not
the exclusive subject of its esse. It receives esse and communicates it to matter in the constitution of the human body. Thus,
unlike the immaterial substances, the human soul is the actuality
of more than its own subsistence.
Aquinas furthermore argues that, like an immaterial substance, the soul’s metaphysical status as principle and subject of
esse renders it incorruptible. Since it is the formal principle of
the esse by which it subsists, it cannot be separated from
existence any more than it can be separated from itself.39 Once
36

For further discussion of Aquinas’s argument for the subsistence of the soul, see
James P. Etzwiler, “Man as Embodied Spirit,” New Scholasticism 54 (1980): 358-77;
Fisher, “Operation and Actuality”; Norman Kretzmann, “Aquinas’s Philosophy of
Mind,” Philosophical Topics 20, no. 2 (1992): 77-101; and Pasnau, Thomas Aquinas on
Human Nature, 48-57. For specific discussion of Aquinas’s inference from the soul’s
status as the seat of intellective operations to its subsistent mode of being, see Fisher,
“Operation and Actuality.”
37
STh I, q. 75, a. 2.
38
See Fisher, “Operation and Actuality”; Klima, “Aquinas on the Materiality of the
Human Soul,” for discussion of this aspect of Aquinas’s view.
39
See STh I, q. 75, a. 6; Q. D. De Anima, a. 14. The same is true for angels (STh I,
q. 50, a. 5). For discussion of Aquinas’s argument for the incorruptibility of the soul, see
B. C. Bazan, “On Angels and Human Beings: Did Thomas Aquinas Succeed in
Demonstrating the Existence of Angels?”, Archives d’histoire doctrinale et littéraire du
moyen-âge 77 (2010): 47-85; Richard Cross, “Is Aquinas’s Proof for the
Indestructibility of the Soul Successful?”, British Journal for the History of Philosophy 5
(1997): 1-20; Eberl, “Aquinas on the Nature of Human Beings”; Joseph Novak, “Aquinas
and the Incorruptibility of the Soul,” History of Philosophy Quarterly 4 (1987): 405-21;
Joseph Owens, “Aquinas on the Inseparability of Soul from Existence,” The New

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KENDALL A. FISHER

it has being, therefore, it simply cannot lose it.40 By contrast, the
matter to which the soul is united can be separated from the
soul, and when it is, the body is corrupted. So, while the body
will cease to be, the soul cannot. This, of course, distinguishes
the soul from all other subsistent parts of the human being. No
other subsistent human part is also the human substantial form,
and thus the principle quo, by which it and the whole have esse.
For this reason, no other subsistent part can exist separate from
the whole.41
The human soul, then, survives death, and Aquinas maintains
that it retains its capacity for intellective cognition. Before death
it served as the seat of intellective acts and it continues to do so
after. Although it no longer has access to the images in the body
that it formerly used to produce intelligible forms, as a
separated intellect it can now receive intelligible forms through
divine influx.42 Through these infused forms it continues to
perform intellective acts as it awaits the resurrection.
With this account of Aquinas’s ontology in place, we are
now in a position to understand how the tension over the soul’s
independence arises and threatens the unity of the human being.
II
The soul’s existential and operational independence generates a prima facie tension in Aquinas’s account of human
ontology. A form that subsists in its own right and can exist and
operate separate from the body—a thing like the human soul—
looks like a complete substance. If it is, it cannot be further
united to anything else (including the body) to form a substanScholasticism 61 (1987): 249-70; Pasnau, Thomas Aquinas on Human Nature, 361-77;
Patrick Toner, “St. Thomas Aquinas on Death and the Separated Soul,” Pacific
Philosophical Quarterly 91 (2010): 587-99.
40
Naturally, that is. It could still be subject to divine annihilation (De Pot., q. 5,
a. 3).
41
STh I, q. 76, a. 8.
42
Q. D. De Anima, a. 15; STh I, q. 89, a. 1.

INCOMPLETENESS OF THE HUMAN SOUL

65

tial unity. Aquinas is well aware of the problem and opens the
first article in his disputed question De anima with the
following objection:
But if the human soul is a hoc aliquid, it subsists and has complete existence
[habens per se esse completum] in its own right. But whatever comes to a thing
after complete existence comes to it accidentally, as whiteness or clothing to a
man. Thus the body, united to the soul, comes to it accidentally. So, if the soul
is a hoc aliquid, it is not the substantial form of the body.43

The objector pits the soul’s status as a subsistent thing, a hoc
aliquid,44 against its capacity to form a substantial unity with the
body and serve as its substantial form. The objection relies on
the following: (A) If the soul is a hoc aliquid, it is complete in
being and has esse in its own right. (B) If it is complete in being,
it cannot be united to anything further except accidentally. (C)
If the soul is united accidentally to the body, it cannot serve as
the substantial form of the body. This objection gains traction in
Aquinas’s metaphysics because of his commitment to the unity
of substantial form. In his view, any created thing, if it exists at
all, does so by means of substantial form. Substantial form not
only confers esse, but determines that esse to a specific substantial nature according to its formal character. This leaves
little room, ontologically speaking, for something that exists
apart from a larger whole but remains specifically incomplete.
The substantial form by which it exists ought to account for its

43

Q. D. De Anima, a. 1, arg. 1 (Marietti 9th rev. ed., 2:281): “Si enim anima
humana est hoc aliquid, est subsistens et habens per se esse completum. Quod autem
advenit alicui post esse completum, advenit ei accidentaliter, ut albedo homini et
vestimentum. Corpus igitur unitum animae advenit ei accidentaliter. Si ergo anima est
hoc aliquid, non est forma substantialis corporis.”
Aquinas’s use of “esse completum” tracks his use of subsistence and existence per se
(see nn. 16, 24). Sometimes he affirms it of things so long as they do not depend on a
subject of inherence (II De Anima, lect. 1). Elsewhere, he reserves it for what subsists
and is complete in a specific nature (De Ente, c. 5).
44
Aquinas’s use of the term hoc aliquid admits of the same strict and loose notions
“subsistence” and “existence per se” (see nn. 16, 24). Consider II De Anima, lect. 1; De
Spir. Creat., a. 2 ad 16.

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KENDALL A. FISHER

existing as a species member in the category of substance. In
that event, it is a complete substance.
In fact, Aquinas himself relies on just this line of thinking
when he articulates the doctrine of the unity of substantial form
in connection with the human soul. He writes,
Indeed anything that comes to a thing after it is complete in being [post esse
completum], comes to it accidentally, since it is outside its essence. However,
every substantial form makes a being complete in the genus of substance, for it
makes a being in act, and a hoc aliquid. Therefore, whatever comes to a thing
after its first substantial form will come to it accidentally.45

In this passage, Aquinas argues that anything united to a thing
after that thing is complete in being (i.e., after it has esse completum) is, at most, united accidentally. This follows because
any additions once a thing has esse completum fall outside its
essence. Since a substance’s existence simpliciter and completeness in a specific nature derive from the same principle, once
the substance exists simpliciter it should be complete in a
specific nature and anything to which it is subsequently united
will fall outside of its essence. Thus, the soul’s capacity to exist
apart from the larger human whole seems to serve as a decisive
indication that it is a complete substance in its own right. Its
formal character ought to determine the esse of which it is a
principle so that it exists as a species member in the category of
substance. But if so, it will be complete in a specific nature and
could be united only accidentally to the body.
Aquinas offers two replies to the objection in the disputed
question De anima. First, he argues that the soul shares
numerically the same esse with the body so that together they
45
ScG II, c. 58 (Leonine ed., 13:409-10): “Omne enim quod advenit alicui post esse
completum, advenit ei accidentaliter: cum sit extra essentiam eius. Quaelibet autem
forma substantialis facit ens completum in genere substantiae: facit enim ens actu et hoc
aliquid. Quicquid igitur post primam formam substantialem advenit rei, accidentaliter
adveniet.”
Here Aquinas seems to be using esse completum and hoc aliquid according to their
strict notions (see n. 44).

INCOMPLETENESS OF THE HUMAN SOUL

67

form a single substance with a single act of being.46 Second, he
maintains that the soul’s esse completum does not, in fact, entail
that it is specifically complete.47 Instead, he claims that the
specific nature (human nature) is only complete when soul and
body are united. It is worth noting that the success of the first
reply depends on the second. Given the unity of substantial
form, the only way for subsistent parts to be unified in a single
substance is for them to share numerically the same act of being
provided by numerically the same form. Because the soul is the
principle of its own esse, to form a single substance with the
body it must be the principle of esse in the body as well. In
other words, it must be the body’s substantial form.
But whether it can be the body’s substantial form depends on
whether it is specifically complete. If the soul were complete in
a specific nature, it could not share its substantial act of being
with the body because the body would fall outside its essence.
Thus, Aquinas needs a plausible defense of how and why the
soul fails to be specifically complete.48 Moreover, such an
account cannot run afoul of his metaphysical principles. For the
theoretical reasons we have just examined, this looks difficult
indeed.
III
Aquinas’s first account of the incompleteness of the soul
appeals to the soul’s operational dependence on the body for its
natural functioning. In his view, humans understand by means
of intelligible forms that inhere in the soul.49 During life, these
46

Q. D. De Anima, a. 1, ad 1. See also De Spir. Creat., a. 2, ad 3.
For discussion of the difference between existential completeness and specific
completeness, see Coulter, “Aquinas on the Identity of Mind”; Patrick Toner,
“Personhood and Death in St. Thomas Aquinas,” History of Philosophy Quarterly 26
(2018): 121-38; VanDyke, “Not Properly a Person.”
48
For discussion of the sense of “body” involved when Aquinas says that the soul
and body are united, see Klima, “Man=Body+Soul”; idem, “Aquinas on the Materiality
of the Human Soul.”
49
ScG I, c. 53; ScG II, c. 98; STh I, q. 85, a. 2.
47

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KENDALL A. FISHER

forms are produced from images, called phantasms, which are
compiled through sensation and stored in the imagination (a
brain-based faculty).50 The process by which intelligible forms
are produced from the phantasms is called “abstraction.”51 All
embodied acts of understanding require that the soul turn
toward the phantasms, either to abstract the intelligible form for
the first time or to reconsider a universal by means of a previously abstracted intelligible form.52 So, although the soul
serves as the subject of the intellective powers and carries out
acts of understanding without the coparticipation of a bodily
organ, those intellective operations depend on the body for the
phantasms.53
Aquinas takes the soul’s dependence on the body as a sign of
its specific incompleteness. In article 1 of the disputed question
De anima, he writes,
Yet in this [human souls] differ from these [higher intellective substances],
since the intellect of the human soul has the nature of acquiring immaterial
knowledge from material knowledge, which is had through sensation. But
inasmuch as it is natural to the soul to acquire immaterial knowledge from
material things, it is clear that the completion of its species cannot be achieved
apart from union with the body. For a thing is not complete in species unless
it has those things which are required for the proper operation of its species.54
50

STh I, q. 79, a. 3; STh I, q. 84, a. 6; STh I, q. 85 a. 5; Q. D. De Anima, a. 4.
STh I, q. 79, a. 3.
52
STh I, q. 84, a. 7; Q. D. De Anima, a. 15; III De Anima, lect. 2 and 10; ScG II,
c. 68.
53
For discussion of the mechanisms of intellective cognition in Aquinas, see Therese
S. Cory, “Averroes and Aquinas on the Agent Intellect's Causation of the Intelligible,”
Recherches de théologie et philosophie médiévales 82 (2015): 1-60; idem, “Rethinking
Abstractionism: Aquinas’s Intellectual Light and Some Arabic Sources,” Journal of the
History of Philosophy 53 (2015): 607-46; Kretzmann, “Aquinas’s Philosophy of Mind.”
For the cooperation between intellective and sensitive powers, see Anton Pegis, “St.
Thomas and the Unity of Man,” in Progress in Philosophy, ed. J. McWilliams
(Milwaukee: Bruce Publishing Co., 1955), 153-73; James Robb, “The Unity of
Adequate Knowing in St. Thomas Aquinas,” The Monist 69 (1986): 447-57.
54
Q. D. De Anima, a. 1 (Marietti 9th rev. ed., 2:284): “In hoc tamen ab eis differunt,
quod intellectus animae humanae habent naturam acquirendi cognitionem immaterialem
ex cognitione materialium, quae est per sensum. . . . In quantum vero immaterialem
51

INCOMPLETENESS OF THE HUMAN SOUL

69

Aquinas explains that human souls differ from higher
intellective substances because human intellects are naturally
suited to understand from material things, which are known
first through sensation. Here he has in mind the soul’s reliance
on phantasms in embodied intellective cognition. We acquire
the means of forming phantasms through our sensitive operations. These phantasms, in turn, contribute to the production of
intelligible forms for our intellective operations. Although the
separated soul can understand through infused rather than
abstracted intelligible forms, this is neither natural to it nor
optimal, and such knowledge is imperfect.55 Since the soul
cannot carry out its natural or proper mode of intellectual cognition without access to the phantasms in the body, it does not
have everything required for its natural or proper functioning.
Hence, it cannot be complete in a nature.
The soul’s operation is a natural place to look when
considering its specific incompleteness. Throughout Aquinas’s
thought, there is a tight connection between nature and
operation: What a thing does is a product of the operative
powers it has, and the operative powers it has are a product of
what it is.56 However, his claim that something specifically
complete must have all those things required for its natural and
proper function is too broad to be compelling. Many operations
essential to complete substances require things that are not part
of the substance itself. If we turn to his account of vision, for
instance, a colored object, light, and a transparent medium are
all required for an animal to see.57 But these are not parts of the
animal, nor would we say that an animal is specifically
incomplete without them. Plants and animals require food and
water to carry out their nutritive functions. Angels require
cognitionem ex materiali est nata acquirere, manifestum est quod complementum suae
speciei esse non potest absque corporis unione. Non enim aliquid est completum in
specie, nisi habeat ea quae requiruntur ad propriam operationem ipsius speciei.”
See also ScG II, c. 68; Q. D. De Anima, a. 7.
55
Q. D. De Anima, a. 15, corp. and ad 21.
56
ScG II, c. 94.
57
II De Anima, lect. 14.

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KENDALL A. FISHER

intelligible forms from God for their intellective operations.
Indeed, if we were to apply this criterion strictly, no created
substance would count as specifically complete. All depend on
God to sustain their being;58 nothing can operate naturally and
properly if it doesn’t exist.
That said, there are some things required for natural and
proper function that, if they were lacking, would, intuitively,
render a thing specifically incomplete. For instance, if a thing
lacked the powers by which its essential operations were performed, then even with the appropriate conditions, input, or
objects it would be incapable of performing its essential operations.59 When we turn to the soul, then, we need to look at the
nature of its dependence on the body, since not every kind of
dependence is sufficient to render the dependent specifically
incomplete.
As it happens, Aquinas is very explicit about the nature of
the dependence of intellective cognition on the body for
phantasms. He explains that the kind of dependence involved is
dependence on an object:
To the first, therefore, it should be said, that the soul requires a body for its
operation in two ways. In one way, as an organ through which it operates, just
as it requires the eye in order to see. And in this way, it does not require any
organ in order to understand, as has been proved. If, however, it required an
organ in this way to understand, it would be corruptible and it would not be
able to operate per se. In another way, the soul requires a body for operating
as an object, just as to see requires a colored body. And in this way the rational
soul requires phantasms for understanding, since phantasms are as sensible
things for the intellective soul as is said in De Anima III. At first, however,
operation which requires a body in this way cannot operate without this body,
but afterwards it can; just as the sensitive soul cannot have any operation
unless it is first moved by a sensible thing which is outside the soul. But
afterwards, the act of the imagination remains even though the sensible thing

58
59

De Pot., q. 5, a. 1.
For discussion of powers in relation to the soul, see below.

INCOMPLETENESS OF THE HUMAN SOUL

71

is removed. Similarly, intellective operation can remain in the soul after the
destruction of the phantasm.60

Here Aquinas distinguishes between an operation’s depending
on a body as an instrument, that is, as an organ in which that
operation is performed, and its depending on a body as an object on which, or from which, it operates. Intellective cognition
relies on a body—the human body—as an object. Just as the
color on the surface of a visible object moves the eye so that the
eye receives a species or form of that color whereby it sees, the
body provides the phantasm by means of which an intelligible
form is produced and received into the soul, through which the
soul understands.61 Thus, while Aquinas maintains that all embodied acts of understanding require the intellect’s turning
toward the phantasm, the phantasm serves as a kind of object in
the process of abstraction.62
The analogy between phantasms and the color of a visible
object is pervasive in Aquinas’s discussions of intellective cognition. He routinely compares the phantasms and the body that
houses them to the color of a wall or stone—especially in his

60
Quodl. X, q. 3, a. 2, ad 1: “Ad primum ergo dicendum, quod anima indiget aliquo
corporali ad suam operationem dupliciter. Uno modo sicut organo per quod operetur,
sicut indiget oculo ad videndum; et sic ad intelligendum non indiget aliquo organo, ut
probatum est. Si autem sic indigeret organo ad intelligendum, esset corruptibilis, utpote
non potens per se operari. Alio modo anima ad operandum indiget aliquo corporali
sicut obiecto, sicut ad videndum indiget corpore colorato; et sic anima rationalis indiget
ad intelligendum phantasmate, quia phantasmata sunt ut sensibilia intellectivae animae,
ut dicitur III de anima. Operatio autem quae sic indiget aliquo corporali, a principio non
potest sine corporali illo, potest autem postea: sicut anima sensitiva nullam operationem
habere potest nisi prius moveatur a sensibilibus quae sunt extra animam, sed praeterea
remanet actus imaginationis, etiam sensibilibus abeuntibus. Similiter destructis
phantasmatibus operatio intellectiva in anima remanere potest.”
61
For discussion of the analogy with vision, see Cory, “Averroes and Aquinas”;
idem, “Rethinking Abstractionism.”
62
Aquinas refers to phantasms as the objects of the agent intellect in the process of
abstraction, but neither they nor the intelligible species are the object which is
understood. The object of our understanding is the universal nature of a material
substance (see STh I, q. 85, a. 2).

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KENDALL A. FISHER

anti-Averroist polemics.63 There he insists that neither the phantasms nor their bodily organs are participants in the soul’s act of
understanding; they only provide the object for abstraction.64
The analogy is also important in his discussion of the subsistence of the soul. To establish that the soul serves as the
incorporeal subsistent part of ourselves with which we perform
intellective acts, he maintains that the body plays no instrumental role in intellective cognition.65 It is involved only insofar
as it provides the phantasms as objects for abstraction.66 Aquinas
could not abandon this characterization of the soul’s dependence on the body and phantasms as an object without
undermining these important philosophical commitments. It is
not, therefore, part of his view that can be jettisoned.
Yet this characterization of the soul’s dependence on the
body or phantasms as an object does not make for a particularly
robust defense of the soul’s specific incompleteness. On
Aquinas’s view, the soul does have the intellective powers
required for performing intellective operations.67 What it lacks
is simply the input on which it performs its abstractive
operation to produce an intelligible form—the object of this
abstractive operation. Paradigmatic cases of complete substances, however, lack as parts those things on which they
depend as objects to perform their essential operations. We do
63
De Pot., q. 3, a. 9, ad 22; STh I, q. 76, a. 1; Q. D. De Anima, a. 2; De Unitate
Intellectus, c. 3; ScG II, c. 59; III De Anima, lect. 7; De Spir. Creat., a. 2.
64
STh I, q. 76, a. 1; De Unitate Intellectus, c. 3; Q. D. De Anima, a. 2; De Spir.
Creat., a. 2.
65
STh I, q. 75, a. 2.
66
This characterization of the dependence on the phantasms may suggest that the
phantasm’s role in abstraction is purely passive. Cory argues for a more active role for
the phantasm—one in which it makes a genuine causal contribution through powerborrowing from the agent intellect (see Cory, “Averroes and Aquinas”; idem,
“Rethinking Abstractionism”). On such an interpretation, however, the phantasm is still
akin to the colored body in vision—indeed, Cory draws heavily on the role of color in
vision in support of her interpretation. Adopting this interpretation, therefore, will not
resolve the specific worry at hand.
67
STh I, q. 77, a. 5, a. 8.

INCOMPLETENESS OF THE HUMAN SOUL

73

not consider the colored wall part of the animal, much less a
part of the animal without which it would be incomplete. The
objects on which or from which a thing acts are often external
to a thing and can be lacked without compromising specific
completeness. But if an animal can be specifically complete even
though it does not have the object that contributes the sensible
forms by which it sees, then it is not clear why the soul should
count as specifically incomplete just because it depends on the
body to provide the object for abstraction. Such an account is
tenuous, at best.
We may think it fitting that the soul be part of something
with the powers and faculties required to produce the phantasms, given that the soul’s optimal and natural function
involves abstraction from phantasms. I believe it is. But more
must be said before we can provide a compelling argument for
why the soul ought to count as specifically incomplete simply
because it depends on the body for the objects it uses in order to
produce the intelligible forms through which it achieves its
natural and proper acts of understanding.
Before we turn away from this first account entirely, it is
worth noting that, for Aquinas, being complete in a specific
nature certainly seems to require the capacity to carry out, in
principle, the operations essential to the relevant specific kind.
His discussion here makes that evident.68 As we have seen, this
may not mean having everything required for the exercise of
these essential operations, but at the very least, it would involve
having the powers and faculties that enable a substance, when in
suitable conditions and presented with an appropriate object (as
required by the operation in question), to operate. The
difficulty with Aquinas’s present account of why the soul fails to
be specifically incomplete, however, is that it happens to satisfy
this criteria—at least with respect to intellective operations. On
these grounds alone, therefore, we cannot rule out the
68

This is also how specific completeness in Aquinas’s thought has been understood
in some contemporary literature. Patrick Toner, for example, characterizes what he calls
completeness in the line of a specific nature as being able to discharge all the proper
operations of one’s natural kind (see Toner, “Personhood and Death”).

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KENDALL A. FISHER

possibility that the soul is specifically complete in some
intellective nature of its own.
IV
Aquinas’s second account of the soul’s specific incompleteness—a more promising one, I believe—appeals to the soul’s
inability to realize all the essential operative powers attendant
on it qua substantial form of the human being through its own
subsistence alone. This, I will argue, provides us with the theoretical resources to offer a principled account of why the soul
fails to be specifically complete in human nature, and moreover
why it cannot be complete in some other intellective nature of
its own.
As we have seen, in Aquinas’s view specific completeness is
closely connected with the ability to discharge the essential
operations of a given specific nature. Human beings are rational
animals, and as such they are essentially capable of rational, sensitive, and nutritive operations. As we have seen, to be rational,
according to Aquinas, a human being must be at least partly
incorporeal, because intellective operations require an incurporeal faculty. Following Aristotle, however, he believes that
nutritive and sensitive operations must be carried out in bodily
organs.69 Thus, to discharge the full range of essential human
operations, the human being must be partly incorporeal and
partly corporeal.
In Aquinas’s metaphysics of creaturely operation, a thing’s
capacity for its essential operations ultimately derives from its
substantial form. This is not because substantial form serves as
the immediate principle or power by which a substance
operates, however.70 Instead, created agents operate

69

STh I, q. 75, a. 4; STh I, q. 76, a. 1; I De Anima, lect. 10; STh I, q. 75, a. 3; STh I,
q. 77, a. 8; Q. D. De Anima, a. 19.
70
Aquinas denies that any created agent operates immediately by means of its
substantial form (STh I, q. 77, a. 1; Q. D. De Anima, a. 12; De Spir. Creat., a. 11).

INCOMPLETENESS OF THE HUMAN SOUL

75

immediately by formal principles of operation, that is, powers,
which, though distinct from the substantial form, naturally flow
forth from that form.71 Though these are technically accidental
forms (since only the first form is substantial, for Aquinas), he
calls them propria or proper accidents because they follow on a
substance’s essential nature.72 Generally speaking, these powers
have as their subject the composite substance (or some subsistent part of it).73 As further actualities inhering in the relevant
bodily organs or parts, they serve as a thing’s immediate formal
principles of operation.74
Like other substantial forms, then, the human soul naturally
gives rise to the powers essential to human life (which include
intellective, sensitive, and nutritive powers). These powers flow
forth from the soul as further actualities that perfect the various
faculties and organs responsible for our essential human operations. The powers themselves inhere in the human being as
formal principles of operation, and yet they do not necessarily
inhere in the human being as a whole. Due to the incorporeal
nature of intellective cognition, no bodily organ can carry out
intellective operations. Aquinas maintains that “that which is
able to operate is the subject of the operative power, for every
accident denominates its proper subject.”75 Thus, the intellective
powers cannot inhere in the body or a bodily organ. Instead, the
soul, apart from matter, serves as the incorporeal, subsistent
faculty in which we perform our intellective acts and, thus, as
71

STh I, q. 77, a. 1; STh I, q. 54, a. 3; Q. D. De Anima, a. 12; De Spir. Creat., a. 11.
STh I, q. 77, a. 1, ad 5.
73
There is an exception in the case of the intellective and volitional powers in
humans, which inhere in the human soul (STh I, q. 77, aa. 5 and 8). Sensitive and
nutritive powers inhere in the composite (ibid.) and, in particular, in the relevant
subsistent parts that serve as their organs (STh I, q. 76, a. 8, ad 4; De Spir. Creat., a. 4,
ad 11; Q. D. De Anima, a. 2, ad 3; Q. D. De Anima, a. 10).
74
STh I, q. 77, a. 1, ad 4; Q. D. De Anima, a. 12.
75
STh I, q. 77, a. 5 (Leonine ed., 5:244): “illud est subiectum operativae potentiae,
quod est potens operari, omne enim accidens denominat proprium subiectum.” For
Aquinas’s location of the powers of the soul in their specific bodily organs, see STh I,
q. 76, a. 8, ad 4; De Spir. Creat., a. 4, ad 11; Q. D. De Anima, a. 2, ad 3; Q. D. De
Anima, a. 10.
72

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KENDALL A. FISHER

the subject of inherence for the intellective powers by which
those intellective acts are performed.76
Because sensation and nutrition involve corporeal motions
and changes, however, sensitive and nutritive operations must
be performed in corporeal organs.77 By the same reasoning,
therefore, the sensitive and nutritive powers must inhere in the
soul-matter composite, that is, the body.78 Indeed, in Aquinas’s
view, the sensitive and nutritive powers inhere in the specific
body parts that serve as their organs.79 Generally speaking,
however, they are actualities proportionate to the potency of a
material subject and cannot be realized in the soul apart from
matter.
For instance, when considering whether such powers remain
in the separated soul, Aquinas insists that they do so not
actually, but only “virtually” (we will come back to this in the
discussion below). The soul-matter composite is their subject,
and no accident can remain after the destruction of its subject.
Thus, the corruption of the soul-matter composite at death
likewise entails the destruction of the powers.80 So while the
soul qua substantial form is the root, principle, or source of the
various intellective, sensitive, and nutritive powers, qua incorporeal subsistent thing it can only serve as the subject of, and
thus realize, the intellective ones.81
In De spiritualibus creaturis Aquinas appeals to the separated
soul’s failure to realize the full range of essential powers of

76

STh I, q. 77, aa. 5 and 8; Q. D. De Anima, a. 10; Q. D. De Anima, a. 19.
See STh I, q. 75, a. 3; STh I, q. 77, a. 8; Q. D. De Anima, a. 19.
78
Aquinas often refers to this as the composite or the “conjoined being”; see STh I,
q. 77, aa. 5 and 8; Q. D. De Anima, a. 19.
79
STh I, q. 76, a. 8, ad 4; De Spir. Creat., a. 4, ad 11; Q. D. De Anima, a. 2, ad 3;
Q. D. De Anima, a. 10.
80
STh I, q. 77, a. 8; Q. D. De Anima, a. 19.
81
Consider also Q. D. De Anima, a. 11, ad 17.
77

INCOMPLETENESS OF THE HUMAN SOUL

77

which it is the principle to account for its specific incompleteness, or as he puts it, its imperfection in nature.82 He writes,
To the fifth it should be said that no part has the perfection of nature when
separated from the whole. Whence the soul, since it is a part of human nature,
does not have the perfection of its nature except in union with the body. This
is clear from the fact that certain powers flow from the soul itself which are
not the actualities of a corporeal organ, insofar as it exceeds the proportion of
the body; and at the same time there flow from it powers which are the
actualities of organs inasmuch as they come to be from the matter of the body.
However, a thing is not perfect in its nature unless it can actually express that
which is virtually contained in it. Whence the soul, although it can exist and
understand when separated from the body, nevertheless does not have the
perfection of its nature when it is separated from the body.83

Here Aquinas points to the soul’s failure to realize fully those
things attendant on it as substantial form as a marker or
indicator of its imperfection in nature: the soul virtually
contains things that cannot be expressed apart from its union
with matter. This, for Aquinas, provides a clear indication that
the soul, on its own, is not complete in a specific nature.
Unfortunately, Aquinas does not offer much of an explanation of what it means for one thing to be virtually contained in
another here. Nor do we find much of an explanation in his
82
In this context and for our purposes, completion and perfection in nature are
roughly interchangeable. Aquinas’s description of the soul as part of human nature
rather than something perfect in human nature echoes the many places where he
explains that the human soul is part of human nature rather than something complete in
human nature. Consider, e.g., Q. D. De Anima, a. 2, ad 11; Q. D. De Anima, a. 7; De
Pot., q. 3, a. 10; STh I, q. 90, a. 4.
83
De Spir. Creat., a. 2, ad 5 (Disputed Questions on Spiritual Creatures, trans. Mary
FitzPatrick and John J. Wellmuth [Milwaukee: Marquette University Press, 1949],
37-38, modified; Marietti 9th rev. ed., 2:371): “Ad quintum dicendum quod nulla pars
habet perfectionem naturae separata a toto. Unde anima, cum sit pars humanae naturae,
non habet perfectionem suae naturae nisi in unione ad corpus. Quod patet ex hoc quod
in virtute ipsius animae est quod fluant ab ea quaedam potentiae quae non sunt actus
organorum corporalium, secundum quod excedit corporis proportionem; et iterum
quod fluant ab ea potentiae quae sunt actus organorum, in quantum potest contingi a
materia corporali. Non est autem aliquid perfectum in sua natura, nisi actu explicari
possit quod in eo virtute continetur. Unde anima, licet possit esse et intelligere a corpore
separata, tamen non habet perfectionem suae naturae cum est separata a corpore.”

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KENDALL A. FISHER

discussions of whether sensitive and nutritive powers remain in
the separated soul.84 Generally speaking, the phrases “continetur
virtualiter,” “continetur virtute,” and their like appear in a
number of contexts. They are sometimes used to describe the
way that premises entail their conclusions or first principles entail an entire science.85 Sometimes they are used to describe how
effects preexist in their causes86 or the way that elements remain
in a mixture.87 Although some of these discussions are quite
removed from the discussion at hand, they do suggest a kind of
prefiguring of the contained in the container. With regard to
souls and substantial forms more generally, such phrases appear
in discussions of how the formal character of a superior form
includes the formal characters of inferior ones—for instance,
how the rational includes that which is contained in the
sensitive and nutritive,88 and how semen or seeds include or
prefigure, in a way, mature substance.89 In such contexts,
however, we do not find a precise working-out of what exactly
this means either (and it seems to differ somewhat from context
to context).
In the present context, Aquinas’s use of the phrase calls to
mind the human soul’s status as the principle or source of a
human being’s essential nutritive, sensitive, and rational powers
insofar as it serves as the actuality of the human being. But
given his commitment to the real distinction between the
essence of the soul and its powers, as well as his rejection of the
84

STh I, q. 77, a. 8; Q. D. De Anima, a. 19; De Spir. Creat., a. 11. In Q. D. De
Anima, Aquinas does observe that the sensitive powers do not actually remain in the
separated soul, but because the soul is of such a kind virtually (“sed quia anima separata
est talis virtutis”) it would cause these powers to exist actually once more, were it to be
reunited to a body.
85
STh I, q. 1, a. 7; STh I, q. 58, a. 4; STh II-II, q. 4, a. 1; STh II-II, q. 44, a. 2; III
Sent., d. 23, q. 2, a. 1, ad 4.
86
STh I, q. 105, a. 1, ad 1.
87
ScG II, c. 86.
88
STh I, q. 76, a. 3, ad 4; STh I, q. 76, a. 4; STh I, q. 76, a. 6, ad 1; De Spir. Creat.,
a. 3; Quodl. I, q. 4, a. 1.
89
ScG II, c. 88.

INCOMPLETENESS OF THE HUMAN SOUL

79

view that all powers of the soul inhere in the soul alone as their
subject, we may wonder in what sense they could be contained
in the soul “virtually.”
In his discussions of the relationship between the soul and its
powers, Aquinas is explicit that the soul is not considered
“rational,” “sensitive,” or “nutritive” simply because it gives rise
to rational, sensitive, or nutritive powers respectively.90 Rather
the soul, already in its essence as substantial form, is a principle
of rational, sensitive, and nutritive being.91 That is, its formal
character calls for the rational, sensitive, nutritive, and corporeal determination of esse.92 Thus, the fact that the powers
spring forth is a consequence of the realization of the soul’s
formal character and not the other way around. We might say
that although the powers of the soul are distinct from the
essence of the soul, they are contained in it virtually on account
of the soul’s formal character as that which determines esse
according to rational, sensitive, and nutritive being. In this way,
the powers of the soul are prefigured in the soul qua substantial
form. Given Aquinas’s metaphysics of operation, this naturally
calls for the relevant powers to flow forth from the soul to
enable the substance actually to carry out those operations
essential to its specific nature.93
90

De Spir. Creat., a. 11, ad 14; STh I, q. 77, a. 1, ad 7; Q. D. De Anima, a. 12, ad 8.
See De Spir. Creat., a. 11, ad 14.
92
For the distinction between the soul as principle of powers and the soul as
substantial form of the body, see Q. D. De Anima, a.19.
93
Raymond Hain proposes a Thomistic-inspired account of the separated soul meant
to safeguard the survival of the human person as the disembodied soul between death
and the resurrection; see Raymond Hain, “Aquinas and Aristotelian Hylomorphism,” in
Aristotle in Aquinas's Theology, ed. Gilles Emery, O.P., and Matthew Levering (Oxford:
Oxford University Press, 2015), 48-69. Hain appeals to the soul’s virtual containment of
the sensitive and nutritive powers as evidence of the fact that the soul retains its essence
as the actuality of an (at least partly) material being. His proposal differs from the
current proposal in three important respects, however. First, it is not introduced in
order to account for the specific incompleteness of the soul, but rather to emphasize the
connection and continuity between the disembodied soul and the human being. Second,
Hain’s proposal departs from Aquinas’s explicitly stated view, as Hain openly
acknowledges. His proposal is not meant as an interpretation of Aquinas but as a
Thomistic-inspired way of resolving concerns about the communion of saints and the
91

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In his discussion of the specific imperfection of the soul in
De spiritualibus creaturis, Aquinas observes that the soul cannot
be perfect or complete in nature because some of the powers of
which the soul is the principle are the actualities of bodily
organs and cannot be realized through its own subsistence
alone, apart from matter.94 These, of course, are the sensitive
and nutritive powers. Such powers are actualities proportionate
to the potency of a material subject—that is, they require a
corporeal subject of inherence and, thus, require the soul’s
union with matter to flow forth. Because the separated soul no
longer communicates the esse of which it is the principle to
matter, those aspects of its formal character that call for the
sensitive and nutritive determination of esse cannot be realized
and, as a result, there is no material subject to serve as the
subject of inherence for the sensitive and nutritive powers. In
the text, Aquinas appeals to the soul’s failure to express certain
things (presumably, the sensitive and nutritive powers) that it
contains virtually as a clear indication of its specific incompleteness or imperfection. Nothing can be perfect in nature if it
cannot express that which it contains virtually.
We may, of course, worry that this account suffers from a
concern similar to the preceding one, namely, that it is too
broad—particularly if we consider Aquinas’s use of “contains
virtually” or “is contained virtually” in other philosophical
contexts, for example, as he uses it to describe the way an effect
is prefigured in its cause. (Presumably a thing can be specifically
complete—and complete as a substance—without actually
fittingness of punishment of disembodied souls in purgatory for human purification.
Third, and most substantive philosophically, Hain maintains that we should understand
the separated soul as not entirely separate from matter since it retains the potency to
interact and change in physical ways. This last aspect of Hain’s proposal is incompatible
with the present proposal. So, although we both recognize the significance of the soul’s
virtual containment of the sensitive and nutritive powers—which in my view reflects the
soul’s formal character and role with respect to determining esse according to sensitive
and nutritive being—our proposals are quite different.
94
STh I, q. 77, a. 5.

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81

bringing about all of the effects of which it is capable.) But if we
focus specifically on virtual containment as it relates to the role
of substantial form as a principle of actuality in created substance, the account may fare better.
In particular, when Aquinas explains that something cannot
be complete or perfect in nature unless that which it contains
virtually is expressed, it seems to be a way of articulating that
perfection or completeness in nature involves or consists in the
full realization of formal character. When a form contains
things virtually, those things are called for by the realization of
its formal character or are attendant on the realization of that
formal character. When the formal character is realized, the
things contained virtually in it are expressed because that which
immediately follows from such a realization (viz., the powers of
the soul) can be realized.
The problem for the soul is that its own subsistence does not,
and never could, fully realize its formal character. As a higher
form, the rational soul virtually contains the formal characters
of sensitive and nutritive souls as well as the corporeity of
material substantial forms.95 The soul is, therefore, an actuality
at least partly proportionate to the potency of matter.96 Apart
from matter, however, none of those aspects of its formal character proportionate to the potency of matter can be realized.
Thus, the full realization of its formal character requires more
than the soul’s own subsistence. Consequently, qua form, the
soul is an incomplete actuality. It cannot express what it contains virtually apart from its union with matter to constitute the
body.
Although Aquinas does not put the point in so many words,
such a proposal fits with his discussions of perfection more
broadly. For instance, he writes,

95

De Spir. Creat., a. 3, ad 16.
Because of its intellective nature, the soul exceeds the capacity of matter (Q. D. De
Anima, a. 2; De Spir. Creat., a. 2, ad 2 and 4). But insofar as it calls for the corporeal,
nutritive, and sensitive determination of esse, it is an actuality proportionate to the
potency of matter.
96

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Yet since each thing is what it is by its form, and since form presupposes
certain things and from form certain things necessarily follow, for a thing to
be perfect and good it must have form as well as that which comes before it
and that which follows upon it.97

Here Aquinas tells us that to be perfect a thing must have form
along with all it presupposes and all that follows from it. He
does not restrict the perfection in question to perfection in nature, but, as a general account, it lends plausibility to the proposal that perfection or completeness in specific nature is tied to
having and completely realizing the formal character of the
form of the species along with those things attendant on the
realization of that formal character. Having and completely
realizing substantial form ensures that something is specifically
complete.98
This, then, provides us with the theoretical resources to account for how and why the intellective soul fails to be specifically complete, despite its capacity for separate existence and
operation. As we saw in Aquinas’s first account of the soul’s
97

STh I, q. 5, a. 5 (Leonine ed., 4:63): “Cum autem unumquodque sit id quod est,
per suam formam; forma autem praesupponit quaedam, et quaedam ad ipsam ex
necessitate consequuntur; ad hoc quod aliquid sit perfectum et bonum, necesse est quod
formam habeat, et ea quae praeexiguntur ad eam, et ea quae consequuntur ad ipsam.”
98
Someone may worry that there are certain essential human powers or propria that
cannot be fully realized except in community with others (my thanks to an anonymous
referee for identifying this potential concern). Or, likewise, there may be human beings
who die prior to exercising certain of their essential powers. In such instances we may
worry that such humans cannot fully realize everything attendant on their soul’s formal
character. In such cases, however, it is important to attend to the real distinction
between the soul and its powers in Aquinas’s account, and to the Aristotelian distinction
he admits with respect to degrees of actuality (see De Spir. Creat., a. 11). An individual
can serve as the subject of a particular power and thus attain a degree of first actuality
with respect to it without exercising that power, that is, without ever actualizing that
power fully. And given that the powers of the soul are, for Aquinas, really distinct from
its essence (STh I, q. 77, a. 1), the actualization of the powers themselves (i.e., their
actual exercise) is not required for the complete realization of the soul’s formal
character as substantial form. A human being cut off from society, or one who dies very
young, may not actually exercise certain powers of the soul, but this does not mean that
such powers fail to flow forth from the soul and inhere in the individual as they ought.

INCOMPLETENESS OF THE HUMAN SOUL

83

specific incompleteness, specific completeness involves being
able, in principle, to discharge the essential operations of the
given specific nature.99 Even in a quite modest interpretation of
such a claim, this requires that the individual in question serve
as the subject of inherence for the essential operative powers.
Things complete in human nature, therefore, must serve as
subjects of rational, sensitive, and nutritive powers.
From the second account, we can see that a thing’s capacity
to discharge the essential operations of a given specific nature
depends on the realization of the formal character of the
substantial form by means of which it exists and those things
immediately attendant on that realization. When a subsistent
thing is only a partial realization of the substantial form by
which it exists, it runs the risk of being unable to serve as a
suitable subject for many of the operative powers attendant on
its nature. If it cannot serve as the subject of the full range of
essential powers, it is incapable, in principle, of discharging the
full range of operations called for by its specific nature. The
more incomplete a realization of the formal character a thing is,
the more likely it is to lack those principles and powers required
for its essential operation, and the more likely it is to be
specifically incomplete.100
This is precisely what we find in the case of the soul,
considered apart from matter. Despite having a formal character
that ought to determine esse so that it exists according to
rational, sensitive, nutritive, and corporeal being, the separated
soul realizes only that which is rational. Those aspects of its
formal character and those powers attendant on that formal
character that are proportionate to the potency of matter,
cannot be realized apart from its union with matter. It is, in
other words, a (very) partial realization of its formal character.
As a result, it cannot, in principle, discharge the full range of
99

See also ScG II, c. 94.
I offer a related proposal of the soul’s substantial incompleteness as part of a
defense of Aquinas against the “too many thinkers problem”—namely, the concern that
where Aquinas should have only one thinker (the human being), he ends up committed
to two (the human being and her soul). See Fisher, “Saint Thomas Aquinas.”
100

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operations essential to the specific nature called for by its
formal character.
Moreover, the fact that the soul’s formal character calls for
nutritive and sensitive realization precludes the soul from being
complete in some other intellective nature of its own. As the
human substantial form, the soul has a given formal character,
namely, that of a rational animal. Aquinas is clear that it does
not lose this formal character, or its propensity to inform
matter, even in its separated state.101 Since it has the formal
character that it does, its own subsistence cannot be a complete
realization of any other form. It cannot, therefore, be complete
in some other specific nature. It can, at most, very partially
realize the formal character that it has qua substantial form. As a
result, it remains specifically incomplete. When we grant that
the soul is the human substantial form, therefore, we can
coherently maintain that it is specifically incomplete, despite its
unique capacity for separate existence.102
On the present proposal, the capacity to exist and operate
independently from some larger whole, though correlated with
specific completeness, is not a decisive indicator of specific
completeness—or of completeness as a substance, for that mat101

The soul retains its formal character as the actuality of a rational animal even
when it is not actually united to matter to constitute a rational animal (Quodl. X, q. 3,
a. 2, ad 4). Aquinas likens it to a lightweight body retaining its tendency to move
upward even when it is held down (Q. D. De Anima, a. 1, ad 10).
102
The success of this account requires that the soul is the substantial form of the
human being. We might worry that this introduces some problematic circularity, since,
as we observed in section II, the soul must be specifically incomplete in order to serve as
the body’s substantial form. Importantly, however, Aquinas does not appeal to the soul’s
specific incompleteness to argue that it is the substantial form of the body (see STh I, q.
76, a. 1). In the present proposal, therefore, we do not saddle Aquinas with using a first
claim to establish a second and then that second to establish the first, which would
indeed be philosophically problematic. So long as Aquinas has independent reasons for
establishing that the soul is the substantial form of the body—and he does (see ibid.)—
we avoid any pernicious circularity in reasoning. Instead, what we have shown is that
the soul’s being the substantial form of the body is necessary for its specific
incompleteness, and its specific incompleteness is necessary for its serving as substantial
form. In short, the claims are consistent; moreover, they will stand or fall together.

INCOMPLETENESS OF THE HUMAN SOUL

85

ter. Furthermore, although the soul is unique in comparison
with the other subsistent parts of the human being (or the
subsistent parts of other material substances more generally)
because of its existential and operational independence from the
larger whole of which it is a part, we can use the very same
rationale to explain why it and other subsistent parts are
specifically incomplete: Any subsistent part, whether existing as
part of a whole or not (in the unique case of the separated soul)
is but a partial realization of the formal character of that form
by which it exists. Hearts, eyes, limbs, or livers partially realize
the formal character of the soul by which they exist. But none
of these completely realizes the formal character of the
substantial form by which it has esse. These parts are such
partial realizations of the formal character of the forms by
which they exist that, on their own, they cannot realize and substand the range of essential powers that follow from the formal
characters in question. As a result, they cannot discharge the full
range of operations essential to the whole, and therefore, they
fail to be complete in the relevant specific nature. By contrast,
the whole substance is a full realization of the formal character
of the form by which it exists. It can, therefore, realize those
powers consequent on that formal character by serving as their
subject of inherence. It is thus capable, in principle, of discharging its essential operations.103
103
It may seem that there are cases that qualify under this account as specifically
incomplete even though they should not—for instance, individuals early on in their life
span that are immature and have yet to develop all that is called for by their formal
character (e.g., a sapling vs. a mature oak). Likewise, we may worry that individuals
who do not have, or have lost, limbs and organs do not fully realize their formal
characters and therefore fail to be specifically complete.
In response to the first, Aquinas could maintain that a thing’s formal character may
be realizable in different ways given its maturity. A sapling may not have all the organs
or features of a fully mature oak, but it nevertheless realizes the formal character of the
form by which it exists in the way appropriate to its current stage of development. That
which is contained in its substantial form, qua principle, is fully expressed relative to its
developmental stage or maturity.
With regard to missing limbs or organs, most need not imperil the specific
completeness of the substance, though the loss of some may, more than others,

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KENDALL A. FISHER

constitute a significant failure to realize fully those things attendant on a thing’s formal
character—e.g., the loss of the sole faculty by which a particular essential operation is
performed. For instance, the loss of one’s nose and all related olfactory organs would
involve the destruction of the power of smell which inheres in these organs. (This is
importantly different from a case where someone’s nose remains but no longer
functions. In the latter case, Aquinas could maintain that the power remains, since its
subject remains, but that there is a deficiency on the side of the material organ that
renders it inoperative.) In the case of altogether missing organs, there seem to be three
avenues for response consistent with the present proposal.
One could bite the bullet and respond that such individuals fail to realize the formal
character of the form by which they have esse and, as a result, indeed fail to be
specifically complete. Such individuals do not fully realize the formal character of the
substantial form by which they have esse since not every power attendant on the
sensitive being characteristic of humans can flow forth and be instantiated. This is
because they have lost the requisite subject for the power of smell. As a result, the
individual does not serve as the subject of all of the powers essential to human life and
therefore cannot, in principle, discharge all the operations essential to human life. For
this reason, the individual fails to count as specifically complete. We might worry that
this means that such an individual is no longer a complete substance, and for
metaphysical purposes, could now be united to other things substantially and not just
accidentally, willy-nilly. But the latter does not necessarily follow. Such an individual
could not be united to just anything to form a substantial union. Most other things
would still fall outside of its essence. The only things to which it could be united
substantially would have to be such that their union constitutes the complete realization
of the individual’s formal character. This would be limited to matter appropriately
disposed to reconstitute the missing limb or organ which, once unified, would undergo
a change in identity and exist by means of the soul. This may not be as counterintuitive
as it initially seems.
If the bullet is too big to bite, then an alternative approach would be to maintain that
such individuals fail to realize fully the formal character of the substantial form by
which they have esse, since one of the powers attendant on that formal character cannot
be realized (as in the first response), but do not, on that account, fail to count as
specifically complete. This response acknowledges—in accordance with the present
proposal—that existing as a partial realization of the formal character of the form by
which one exists puts one at risk of specific incompleteness. (It puts one at risk of being,
in principle, incapable of discharging the range of operations essential to the relevant
specific nature since some of the requisite powers may lack a suitable subject). But it
maintains that the partiality of the realization of the formal character in this instance,
where an individual retains other sensitive powers, is not sufficient to threaten specific
completeness. The fact that they can perform other sensitive operations allows them to
satisfy the criteria of being able, in principle, to discharge the operations essential to
human life, generally speaking, and this renders them specifically complete in human

INCOMPLETENESS OF THE HUMAN SOUL

87

V
One might worry that the account offered in section IV
cannot be reconciled with Aquinas’s claim that after a thing has
esse completum it cannot be united to anything further except
accidentally. If we take that claim baldly, then regardless of
whether the soul is incomplete in some other way, the fact that
it has esse completum apart from matter precludes it from
forming something unqualifiedly one in its union with matter to
form the body. However, even in the passage from Summa
nature. On this view, human beings would have to lose all the sense organs and powers
in their bodies before they would truly lack the capacity for discharging the sensitive
operations essential to human life (and given the pervasiveness of the organ of touch, it
isn’t clear that any human being could survive such a loss). The soul, by contrast, cannot
realize any of the sensitive or nutritive powers whatsoever. This indicates that those
aspects of its formal character that call for the determination of esse to sensitive,
nutritive, and corporeal being are not realized.
Finally, one might respond that such individuals neither fail to realize fully the
formal character of the substantial form by which they have esse in the most relevant
sense, nor fail to be specifically complete. According to this response, such individuals
remain specifically complete because they can still, in principle, discharge rational,
sensitive, and nutritive operations (as in the second reply). In this view, the presence of
these powers indicates that the formal character is still fully realized, despite the fact
that one of the sensitive powers typical of human sensitive being cannot flow forth as it
normally would. Thus, the soul’s formal character calls for the sensitive determination
of esse, and the realization of other sense powers is sufficient indication of that
realization. In other words, the soul’s formal character, so far as it is the actuality of a
human being, is fully realized. On this view, the full realization of the formal character
of the substantial form does not require the realization of the powers that naturally flow
from it (which admittedly distances it from Aquinas’s discussion in De Spir. Creat.)
However, this view takes the failure to realize any powers of a particular kind as an
indication of a failure to realize formal character. In this regard, therefore, it would
distinguish between the present case and that of the separated soul.
All three of these responses are consistent with the present proposal, though each
involves a slightly different cashing out of what is involved in the complete realization
of formal character (i.e., whether this involves only the realization of those powers
attendant on it or not) and what it means to be, in principle, capable of discharging the
operations essential to the specific kind (i.e., whether this should be understood
generally as having the power to perform at least some rational, sensitive, and nutritive
operations or more specifically as having the powers to perform exactly those
operations characteristic of the specific kind).

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contra gentiles quoted in section II, Aquinas does not identify
esse completum as the fundamental barrier to further
unqualified union.104 The concern is that once a thing has esse
completum it is complete in an essence, and so anything further
to which it is united must fall outside that essence. The
fundamental barrier is completeness in essence.
As we have seen, esse completum and completeness in
essence or nature typically go hand in hand, so it is perhaps unsurprising that Aquinas would sometimes speak as though esse
completum entails completeness in essence. But if the fundamental barrier to substantial union is completeness in essence,
then a thing with esse completum could be united to something
further to form a substantial unity so long as it is incomplete in
essence and the union in question results in the completion of
that essence and nothing more. This is precisely what we find in
the case of the soul. Although the soul can exist apart from the
larger human whole, it cannot completely realize its formal
character. It has esse completum but it is not complete in its
essence. Moreover, those aspects of the soul’s formal character
that require corporeal realization are realized through the soul’s
union with matter to form the body. The body, therefore, does
not fall outside of the essence called for by the soul’s formal
character, but completes it.105
Furthermore, we can appeal to considerations from section
III to explain why the human substantial form is the kind of
thing whose formal character calls for corporeal and incorporeal realization and, likewise, why it is the principle of
sensitive and nutritive powers as well as intellective ones.
Because the human intellect is the lowest of the intellects and
naturally suited to understand from material things, it is fitting
that the human being have within herself the full range of
powers for the proper and optimal functioning of her intellect.
104

ScG II, c. 58.
In some places Aquinas explicitly mentions the exception to this line of reasoning,
namely, when two things are united by means of numerically the same act of existence
(I Sent., d. 17, q. 1, a. 2; STh III, q. 2, a. 6, ad 2).
105

INCOMPLETENESS OF THE HUMAN SOUL

89

Only a partly corporeal, partly incorporeal being could have the
requisite sensitive and intellective faculties to understand
through abstracted intelligible forms. So, it is fitting that the
substance with such an intellect be partly corporeal and partly
incorporeal. These considerations help to explain why the
human being—and the human soul—have the unique ontological status that they do.
CONCLUSION
The concern that the human soul ought to count as something complete in its own right depends on the intuition that
separate existence and operation are sufficient to render a thing
complete in a nature. But this is not the only account one can
offer of specific incompleteness. Instead, Aquinas can maintain
that a thing can fail to be complete in its specific nature by
failing to realize the formal character of the form by which it
exists. Doing so provides a means of reconciling the soul’s
capacity for separate existence with its union with the body.
In life and death alike, the soul is but a partial realization of
its formal character—a realization that cannot, on its own,
substand the full range of essential powers attendant on its
nature. It is for this reason that the soul is specifically
incomplete. Only when the soul is united to matter as the
actuality of the body is the result something that fully realizes
the soul’s formal character as the substantial form of a rational
animal, including the full range of powers essential to human
life. Accordingly, only when the soul is united to the body as its
actuality do we have something specifically complete. For this
reason, the rational soul can be hylomorphically united to prime
matter to constitute the human body and form with it a single
substantial unity, the human being.106
106

Special thanks to Kara Richardson for comments on and discussion of previous
versions of this article. Thanks also to the participants at the Symposium on Medieval
and Renaissance Studies (Saint Louis University, June 17, 2019) where I presented an
earlier version of this article.

The Thomist 86 (2022): 91-117

PAIN MANAGEMENT, THEOLOGICAL ETHICS, AND THE
PROBLEM OF REDEMPTIVE SUFFERING:
A THOMISTIC ANALYSIS
STEWART CLEM
Aquinas Institute of Theology
Saint Louis, Missouri

“Physical pain always mimes death and the infliction of physical pain is always
a mock execution.” – Elaine Scarry1
“Sorrow in the heart exceeds every external wound.” – St. Thomas Aquinas2
“I am strapped up with a broken rib, of all things. I broke it coughing. I never
knew such was possible but I warn you: if you get a cough, buy yourself some
cough syrup, don’t just sit around coughing.” – Flannery O’Connor3

M

OST CHRISTIANS believe that it is morally acceptable, within certain parameters, to minimize one’s
pain through medication. We find this affirmation
especially in contemporary analyses of cases in which patients
are in the process of dying. According to the Ethical and
Religious Directives for Catholic Health Services, “[dying] patients should be kept as free of pain as possible so that they may
die comfortably and with dignity,” and, moreover, “Medicines
1
Elaine Scarry, The Body in Pain: The Making and Unmaking of the World (New
York: Oxford University Press, 1985), 31.
2
“Tristitia cordis omnem plagam exteriorem excedit” (STh I-II, q. 35, a. 7, s.c., commenting on Sir 25:17). Quotations from the Summa are my own, based on the Corpus
Thomisticum text of the Fundación Tomás de Aquino at www.corpusthomisticum.org.
This text is based on the Leonine Edition, transcribed by Fr. Roberto Busa, S.J., and
revised by Enrique Alarcón (Pamplona: Fundación Tomás de Aquino, 2012).
3
Flannery O’Connor, Letter to Cecil Dawkins, December 9, 1958, in The Habit of
Being: Letters of Flannery O’Connor, ed. Sally Fitzgerald (New York: Farrar, Straus and
Giroux, 1988), 307.

91

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capable of alleviating or suppressing pain may be given to a
dying person, even if this therapy may indirectly shorten the
person’s life so long as the intent is not to hasten death.”4 Most
moral theologians and Christian health-care ethicists would
agree that pain is an evil to be avoided and that medical
practitioners who help patients alleviate pain are doing good.
Yet, as we all know, pain medications are not always effective. Sometimes we may wish to alleviate a patient’s pain, yet
we are unable to do so. According to the ERD, “Patients experiencing suffering that cannot be alleviated should be helped
to appreciate the Christian understanding of redemptive suffering.”5 In a similar vein, Benedict Ashley, Jean deBlois, and
Kevin O’Rourke write, “Although suffering is to be alleviated
whenever possible, it is not in itself a moral evil nor without
supernatural benefits if rightly used. The Christian tradition
holds that great spiritual good can come out of suffering when
it is joined to the sufferings of Jesus.”6 On this account, it seems
that (1) pain is an evil to be avoided, yet (2) there are specific
goods that may be found in the suffering brought about through
pain, and, (3) the goods brought about through pain are not
necessarily greater than the goods brought about through the
alleviation of pain.
To complicate matters further, Ashley, deBlois, and
O’Rourke suggest that
the opportunity to use suffering as a means of spiritual growth is not
destroyed if pain-killing drugs are used. Rather, the individual and those who
care for him or her have the right to use such drugs in a way that will permit
the best use of the patient’s remaining energies and time of consciousness, so
that the patient can complete life with maximal composure.7

4

Ethical and Religious Directives for Catholic Health Care Services, 6th ed.
(Washington, D.C.: United States Conference of Catholic Bishops, 2018), 61. Hereafter
referred to as ERD.
5
Ibid.
6
Benedict M. Ashley, Jean deBlois, and Kevin D. O’Rourke, Health Care Ethics: A
Catholic Theological Analysis, 5th ed. (Washington, D.C.: Georgetown University Press,
2006), 198.
7
Ibid.

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This claim goes beyond the recommendation to seek redemption in the suffering brought about through pain when
pain medication will not work. It suggests, rather, that the
goods normally brought about through the experience of pain
can be pursued while actively striving to alleviate one’s pain.
There is at least an apparent paradox here that warrants an
explanation.
The aim of this article is to propose just such an explanation,
and this explanation hinges on a particular account of pain as a
passion of the soul known to the medieval Scholastic theologians as dolor (Latin, “pain”). On this account, pain is a postlapsarian response to the corruption of the body resulting from
the loss of original justice.8 I draw upon St. Thomas Aquinas’s
distinction between bodily pain (dolor) and sadness (tristitia) to
illuminate pain’s moral significance. I argue that this account
allows for a qualified defense of pain management through
medication, insofar as this practice aims to remove obstacles to
the contemplation that is requisite for living a good life—and
for dying a good death. I also argue that this account makes
room for the notion of redemptive suffering, but it does so
without fetishizing bodily pain, insofar as it delineates clear
limits on one’s “participation” in the suffering of Christ.
I. WHAT IS PAIN? A NEUROSCIENTIFIC VIEW
The neuroscientific and clinical research on pain is vast, and
I have no aspirations of contributing to—or adequately
summarizing—that discourse here. My aim, rather, is to provide
an analysis of bodily pain from the perspective of theological
anthropology, and I take it for granted that any such analysis
should be informed by (or at least in conversation with)

8
See, for example, STh I-II, q. 85, a. 5, where Aquinas explains that certain bodily
defects (i.e., those found in all human beings, not “deformities,” in the colloquial sense
of “defects”) are the result of original sin. In STh I-II, q. 85, a. 6 he defends the view
that God created the human body, in the original state of justice, to be incorruptible.

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contemporary scientific research.9 Even so, my aims are modest.
The most I can do in a brief article is to sketch a preliminary
theological analysis of pain that merely gestures at moral
guidelines for clinical practice. This analysis will raise many
important questions that will remain unanswered. Nonetheless,
there is a great need for this kind of analysis, given the
surprising dearth of contemporary theological work in this
area.10 As Christians, we cannot adequately reflect on the
meaning of pain or the ethics of pain management without an
adequate account of what pain is from the perspective of theological anthropology.11 For the moral theologian, to ask what
pain is is to ask what the experience of pain tells us about being
human. Our answer to this question will be theologically
inflected and will reveal additional philosophical and theological presuppositions along the way.
From one neuroscientific perspective, pain is the body’s
adverse response to stimuli.12 Yet even this simplistic definition
9
For a sophisticated and nuanced theological engagement with neuroscience, see
Neil Messer, Theological Neuroethics: Christian Ethics Meets the Science of the Human
Brain (New York: T&T Clark, 2017). Messer’s book does not address the central
concerns of this article, but it provides a helpful model for bringing theological ethics
into conversation with contemporary scientific literature.
10
For a helpful starting point on the theology of suffering (including but not limited
to bodily pain) within the context of medicine, see the selections in chapter 9 of On
Moral Medicine: Theological Perspectives in Medical Ethics, 3rd ed., ed. M. Therese
Lysaught and Joseph Kotva (Grand Rapids, Mich.: Eerdmans, 2012); Jason Eberl,
“Religious and Secular Perspectives on the Value of Suffering,” National Catholic
Bioethics Quarterly 12 (2012): 251-61; see also the essays in part 4 of Suffering and
Bioethics, ed. Ronald M. Green and Nathan J. Palpant (New York: Oxford University
Press, 2014).
11
Perhaps the most important volume produced in the twenty-first century on the
intersection of pain and theology is Sarah Coakley and Kay Kaufman Shelemay, eds.,
Pain and Its Transformations: The Interface of Biology and Culture (Cambridge, Mass.:
Harvard University Press, 2007). While several authors in this volume propose promising paths for further exploration (some of which I engage in what follows), the scientific
research it draws upon is already somewhat dated, and there has been little work on this
topic since its publication. The present article is an attempt to remedy the situation.
12
See Jörg Trojan et al., “Body, Space, and Pain,” Frontiers in Human Neuroscience
8, no. 369 (2014): 1-3; Amelia Swift, “Understanding Pain and the Human Body’s
Response to It,” Nursing Times 114, no. 3 (2018): 22-26.

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is loaded with axiological assumptions. What makes the body’s
response “adverse”? Is it because we experience an unpleasant
feeling when we sense pain? If so, then what are we to make of
the fetishist who claims to find pleasure in painful sensations? Is
it because pain serves an objective function—namely, our own
survival? If so, then we can only say this unequivocally when we
are describing the function of pain at the phylogenetic level; at
the ontogenetic level, we know that pain often serves no
meaningful function at all and in fact can inhibit many human
activities, as is the case with many neurological disorders. It is
also far from clear what counts as a “stimulus.” While there is
little doubt that a nail piercing through the sole of one’s foot
falls in this category, it is less clear whether something like a
painful memory counts as stimulus, at least in the same sense. In
the former example, an external physical event causes (or
corresponds with) a mental or psychological state: stepping on a
nail hurts.13 But painful memories can also hurt. In the case of a
painful memory, a mental state causes (or corresponds with) a
physical condition (say, an upset stomach), which results in the
sensation of bodily pain.
Howard Fields describes these different experiences of pain
as a difference in “meaning.” He writes, “Imagine the difference
between a headache sustained after a bout of heavy drinking
and an equally severe headache the week after learning that
one’s identical twin brother with a similar headache was
diagnosed with a malignant brain tumor. In these two examples,
13
These are highly contested debates within the philosophy of mind, touching on
questions related to mind-brain identity theory, functionalism, epiphenomenalism, and
the like. My purpose here is not to engage those debates, but I should note that the
contentiousness of these issues only underscores how difficult it is to provide a
philosophically neutral definition of pain. For a highly accessible introduction to these
and related questions in philosophy of mind, see Edward Feser, Philosophy of Mind: A
Beginner’s Guide (Oxford: Oneworld, 2006). For a constructive, nonreductionistic
account of the body-soul relationship and its relevance to contemporary mental health
practice, see Paul C. Vitz, William J. Nordling, and Craig Steven Titus, eds., A Catholic
Christian Meta-Model of the Person: Integration with Psychology and Mental Health
Practice (Sterling, Va.: Divine Mercy University Press, 2020).

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although a similar peripheral signal was at work, the meaning
was completely different.”14 Of course, a painful memory may
not involve the sensation of bodily pain. Reflecting on a traumatic experience may constitute suffering without the corresponding physical sensation, although this line is often blurred.
As Stanley Hauerwas writes, “suffering, which is not the same as
pain since we can suffer without being in pain, is nonetheless
akin to pain inasmuch as it is a felt deficiency that can make us
as miserable as pain itself.”15 But the point is that pain, often
understood to be a mental state, can also be the result of a
mental state, which renders pain’s relationship to external
stimuli even more opaque.
Clifford Woolf defines pain as “the conscious awareness of a
sensory experience that is unpleasant, distressing, or disturbing.”16 Woolf is among the minority of pain theorists who
believes that pain is ultimately reducible to scientific scrutiny
and that it is “amenable to a deterministic dismantling of the
molecular components of the nervous system.”17 He does not,
of course, deny that pain can have many additional layers of
subjective and cultural meaning. While he rightly observes that
“what makes pain different from all other sensory experiences
. . . is that the sensation is linked inescapably and integrally with
a conscious awareness of its unpleasantness,” he prefers a purely
physiological model of pain that reduces its subjective or
emotional experience to that of sensation.
Not all contemporary models of pain demand such reductivism. One of the most prominent contemporary models of

14

Howard L. Fields, “Setting the Stage for Pain: Allegorical Tales from
Neuroscience,” in Coakley and Shelemay, eds., Pain and Its Transformations, 46.
15
“Salvation and Health: Why Medicine Needs the Church,” in Stanley Hauerwas,
The Hauerwas Reader, ed. John Berkman and Michael Cartwright (Durham, N.C.: Duke
University Press, 2001), 549.
16
Clifford J. Woolf, “Deconstructing Pain: A Deterministic Dissection of the
Molecular Basis of Pain,” in Coakley and Shelemay, eds., Pain and Its Transformations,
27.
17
Ibid.

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pain is the biopsychosocial model,18 which, as the name suggests, insists that pain “is best understood when biological,
psychological, and social viewpoints are integrated.”19 Drawing
upon this model, the International Association for the Study of
Pain updated its definition of pain in July 2020, for the first
time since 1979. The revised 2020 definition states that pain is
“an unpleasant sensory and emotional experience associated
with or resembling that associated with actual or potential tissue
damage.”20 The previous definition omitted the clause “or
resembling that associated with.” By adding this designation, the
new definition acknowledges that “pain and nociception are
different phenomena. Pain cannot be inferred solely from
activity in sensory neurons,” and, furthermore, “Through their
life experiences, individuals learn the concept of pain.”21 This
definition of pain, informed by the biopsychosocial model, does
not suggest that pain can have an additional, subjective layer
added onto it, but rather that pain is an inherently multifaceted
phenomenon that necessarily includes its subjective dimensions.

18

This model of pain is a more specific application of the biopsychosocial model of
illness, first articulated in the seminal essay by George L. Engel, “The Need for a New
Medical Model: A Challenge for Biomedicine,” Science 196 (1977): 129-36; For a
recent assessment of this model and its reception and application within contemporary
medical practice, see Derick T. Wade and Peter W. Halligan, “The Biopsychosocial
Model of Illness: A Model Whose Time Has Come,” Clinical Rehabilitation 31 (2017):
995-1004; For an example of this model’s potential for practical applications in pain
management, see Amarins J. Wijma et al., “Clinical Biopsychosocial Physiotherapy
Assessment of Patients with Chronic Pain: The First Step in Pain Neuroscience
Education,” Physiotherapy Theory and Practice 32 (2016): 368-84.
19
Mustafa al’Absi and Magne Arve Flaten, The Neuroscience of Pain, Stress, and
Emotion: Psychological and Clinical Implications (San Diego, Calif.: Academic Press,
2016), xi.
20
Srinivasa N. Raja et al., “The Revised International Association for the Study of
Pain Definition of Pain: Concepts, Challenges, and Compromises,” Pain 161 (2020):
1976-82.
21
Ibid.

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II. PAIN AS A PASSION OF THE SOUL: A THOMISTIC ACCOUNT
A widely used textbook on the neuroscience of pain observes
that the IASP definition helps us to conceptualize the emotional
content of pain. As the authors explain, this definition
also clarifies that negative emotions are a constituent of the pain experience,
and therefore a close interaction or overlap between brain processes related to
pain and emotions has to be expected. As a matter of fact, it may be argued
that pain is an emotion, an emotion that requires the presence of a bodily
sensation with qualities like those reported during tissue-damaging
stimulation.22

What is remarkable about this description is its striking similarity to the medieval Scholastic understanding of the passions.
While I am admittedly glossing over some significant conceptual
differences, the two categories share similar features. The
passions, while not quite synonymous with our modern concept
of emotions, are understood as psychological processes that
involve the body.23 They are what we would call psychosomatic.
The classic definition of the passions, frequently cited by later
medieval authors, is attributed to John of Damascus. He defines
a passion as “a movement of the sensitive appetite in which
good or evil is imagined. Put another way, a passion is a
movement of the irrational soul by means of a perceived good
or evil.”24 We should not think of good and evil in grand
metaphysical or cosmic terms here. Rather, they simply refer to
22

al’Absi and Flaten, Neuroscience of Pain, Stress, and Emotion, 3. While the authors
cite the older IASP definition of pain, their commentary is still relevant since it is
highlighting the “unpleasant sensory and emotional experience” of pain, which was
included in the previous definition.
23
For a helpful analysis of Aquinas’s theory of sense perception and its role in the
passions, in conversation with contemporary psychology, see Benedict M. Ashley, O.P.,
Healing for Freedom: A Christian Perspective on Personhood and Psychotherapy
(Arlington, Va.: The Institute for the Psychological Sciences Press, 2013), chap. 4.
24
Quoted by Aquinas in STh I-II, q. 22, a. 3, s.c., citing De Fide Orth. 2.22: “Sed
contra est quod dicit Damascenus, in II libro, describens animales passiones, passio est
motus appetitivae virtutis sensibilis in imaginatione boni vel mali. Et aliter, passio est
motus irrationalis animae per suspicionem boni vel mali.”

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good or bad things to be pursued or avoided. If one is on a hike
in the woods and suddenly comes upon the edge of a steep cliff,
this is an evil to be avoided. If on this same hike one is thirsty
and comes upon a fresh stream of water, this is a good to be
embraced. The fact that these movements belong to the
“irrational appetite” underscores their similarity to animal
instinct, although we should not lose sight of the fact that the
passions are distinctly human.
Aquinas approvingly cites John Damascene’s definition of
the passions, but he also offers an important addendum:
“Properly speaking, a passion is found where there is bodily
transmutation, which is located in the act of the sensitive
appetite. This is not only spiritual (as it is in sensitive
apprehension) but also natural.”25 What this analysis captures is
the irreducibly psychosomatic nature of the passions. They are
neither mere bodily responses to stimuli nor purely mental
occurrences. As Robert Miner explains,
The passions are in the sensitive appetite, but the sensitive appetite itself
belongs to the form/matter composite, since it requires a bodily organ for its
operation. . . . Since the acts of the sensitive appetite necessarily involve a
bodily organ, passions cannot be essentially attributed to the soul (unlike
thoughts or volitions). And yet because they are formally shaped by the soul’s
apprehension, they are not simply acts of the body. Hence Aquinas concludes
that their subject can only be the composite.26

Aquinas’s understanding of the human being as a composite
reflects his (along with many other Scholastics’) commitment to
the Aristotelian doctrine of hylomorphism. In the simplest
terms, hylomorphism maintains that the soul is the form of the
25
STh I-II, q. 22, a. 3: “Respondeo dicendum quod, sicut iam dictum est, passio
proprie invenitur ubi est transmutatio corporalis. Quae quidem invenitur in actibus
appetitus sensitivi; et non solum spiritualis, sicut est in apprehensione sensitiva, sed
etiam naturalis.”
26
Robert Miner, Thomas Aquinas on the Passions: A Study of Summa Theologiae,
1a2ae 22-48 (New York: Cambridge University Press, 2009), 32. Miner offers an
illuminating analysis of Aquinas’s definition of the passions in ibid., 29-57.

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body. Soul and body can be distinguished, but they are not
independent entities—this is not the dualism of Descartes.27
Aquinas writes, “There is no passion . . . without a correspondding bodily transmutation. Thus, properly speaking, a passion
cannot be said to reside in the soul unless we mean accidentally,
insofar as the composite [of body and soul] is passive.”28 While
passions are powers of the soul, the activity of the passions is
not to be understood as the soul “acting” on the body (or vice
versa) but rather as something that happens to the human being.
While the medieval Scholastics often developed their own
highly detailed schematics of the passions, their writings reflect
a broad consensus about the fundamentals. This is thanks in
part to the systematizing efforts of Isaac of Stella, who
articulated the four principal passions as joy (gaudium), hope
(spes), fear (timor), and pain (dolor).29 This classification was
popularized through its inclusion in Philip the Chancellor’s
Summa de bono and serves as a starting point for others’ work
on the passions.30 Aquinas’s analysis of the passions in his
27

Interestingly, Raja et al. observe that criticisms of the older IASP definition “have
included that it is ‘Cartesian,’ ignoring the multiplicity of mind-body interactions” (Raja
et al., “The Revised International Association for the Study of Pain Definition of Pain,”
1977). The revised definition resonates more with a hylomorphic understanding of the
human being.
28
STh I-II, q. 22, a. 1: “Passio autem cum abiectione non est nisi secundum transmutationem corporalem, unde passio proprie dicta non potest competere animae nisi
per accidens, inquantum scilicet compositum patitur.” Nicholas Lombardo notes that in
Aquinas’s earlier works he describes some passions (including dolor) as passiones
corporalis (passions of the body), as opposed to passiones animalis (passions of the soul).
See Nicholas E. Lombardo, O.P., The Logic of Desire: Aquinas on Emotion
(Washington, D.C.: The Catholic University of America Press, 2011), 44-46. Aquinas’s
later work downplays this distinction, however; what is important is the body-soul
character of the passions. I am not convinced by Lombardo’s claim (ibid., 228-29) that
the corporalis/animalis distinction retains its significance in Aquinas’s mature thought on
the passions.
29
Isaac of Stella, Sermo 17, ad 11: “De amore gaudium et spes, de odio timor et
dolor oriuntur” (Sermons I [Sermons 1-17] [Sources chrétiennes 130], ed. Anselm Hoste
and Gaston Salet [Paris: Cerf, 1967], 318).
30
Philip the Chancellor, Summa de bono, ed. Nikolaus Wicki (Bern: Francke, 1985),
789. The development of this list can be traced even further back to Cicero, who

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Summa is the most extensive in medieval literature, and while it
is innovative in several respects, it too relies on this basic fourfold classification of joy (gaudium), pain (tristitia), hope (spes),
and fear (timor).31 In fact, Aquinas goes so far as to say that joy
and pain are “are said to be principal because it is in them that
all other passions find their completion and end.”32 On his
account, pain belongs to a binary of passions (or “emotions,” if
we are careful to qualify this term) that lie at the heart of
human experience.
In his analysis of the specific passion of pain, Aquinas makes
a very important move. He observes that some authors use the
Latin word dolor, while others use tristitia, but he finds both
terms acceptable. While he acknowledges that dolor and tristitia
share a common root and may be interchangeable in some
contexts, he also believes that each term captures something different and important about the sensitive appetite. In the questions on the passion of dolor or tristitia (STh I-II, qq. 35-39), he
designates dolor to mean “pain,” which specifically refers to
“bodily pain” (he notes that this “is its more usual meaning”)33
and tristitia to mean “sadness,” which refers to an interior
apprehension.34 He writes, “only the pain that is caused by
interior apprehension is called sorrow,” and “pain that is caused

identified the four principal passions as pleasure (laetitia), desire (libido), fear (metus),
and pain (aegritudo). See Cicero, Tusculan Disputations 4.11 (trans. J. E. King, Loeb
Classical Library 141 [Cambridge, Mass: Harvard University Press, 1927]).
31
STh I-II, q. 25, a. 4.
32
Ibid.
33
STh I-II, q. 35, a. 2, ad 3. It is likely that Aquinas is drawing upon the distinction
Augustine draws between dolor and tristitia in The City of God (De civitate Dei contra
paganos), 14.15. While Aquinas does not cite this specific passage, he does cite other
portions of De civ. Dei 14 throughout question 35.
34
Although he does not cite Aquinas, John Paul II makes a similar distinction
between “physical suffering” and “moral suffering” in Salvifici doloris (“On the Christian Meaning of Suffering”), February 11, 1984, 5; http://www.vatican.va/content/ johnpaul-ii/en/apost_letters/1984/documents/hf_jp-ii_apl_11021984_salvifici-doloris. html.

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by exterior apprehension is called pain but not sorrow.”35 Thus,
“pain” (dolor) can sometimes be used generically to refer to
pain or sorrow, but properly speaking it refers to bodily pain.36
We must be careful, however, not to mistake dolor for a
physical sensation and tristitia for a mental state. For Aquinas
the passions always involve bodily transmutation. Suppose, for
example, a person taking a stroll comes across a severely injured
stray dog. She thinks, “Isn’t that a shame,” and looks away,
carrying on with whatever she was doing. This person has not
experienced the authentic passion of tristitia, because it has not
taken hold of her. It has not affected her or caused her to feel
anything.37 Pain and sorrow are movements of the sensitive
appetite and will always involve the body in some way. Aquinas
explains, “The cause of pain is in the body, for instance when
one suffers something harmful to the body. But pain’s movement is always in the soul, since ‘the body cannot feel pain
without the soul feeling it,’ as Augustine says.”38 The term
“bodily pain” simply refers to pain whose origin lies in exterior
apprehension, whether it be a paper cut or a herniated L4-L5
disc. The term “sorrow” refers to pain whose origin lies in
interior apprehension and could arise from hearing some bad
news or from simply reflecting on an unpleasant thought.

35
STh I-II, q. 35, a. 2: “Et similiter ille solus dolor qui ex apprehensione interiori
causatur, nominatur tristitia. . . . ita ille dolor qui ex exteriori apprehensione causatur,
nominatur quidem dolor, non autem tristitia.”
36
Aquinas states that sorrow (tristitia) is a species of pain (dolor) (ibid.). He says this
because dolor can be used in a general sense, to encompass tristitia, or in the more
specific sense of bodily pain, whereas tristitia always refers to interior apprehension.
37
Aquinas elsewhere draws a connection between sorrow (tristitia) and mercy
(misericordia). In STh II-II, q. 30, a. 1 he defines mercy as a “heartfelt sympathy for
another’s distress, moving us to help the other person if we are able,” and in the sed
contra he defines mercy as a kind of sorrow. I am grateful to Jason Eberl for bringing
this connection to my attention.
38
STh I-II, q. 35, a. 1, ad 1: “Ad primum ergo dicendum quod dolor dicitur esse
corporis, quia causa doloris est in corpore, puta cum patimur aliquod nocivum corpori.
Sed motus doloris semper est in anima, nam corpus non potest dolere nisi dolente anima,
ut Augustinus dicit.”

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III. THE MORAL SIGNIFICANCE OF DOLOR AND TRISTITIA
For Aquinas, all passions have inherent moral significance
because they are the subject of the moral virtues.39 Dolor and
tristitia reside in the concupiscible appetite, and the concupiscible appetite is perfected by the virtue of temperance or
moderation.40 Here the distinction between dolor and tristitia
comes into sharp relief. While it is perhaps not difficult for us to
imagine how a virtuous person might moderate her sorrow
(tristitia) or redirect it toward a fruitful end, most people would
reject the idea that one’s pain (dolor) is subject to psychological
moderation in the same way. Granted, we might want to
acknowledge that a virtuous person will be better equipped to
cope with her pain than a person who does not possess the
virtue of temperance. By the same token, we can imagine emotional grief so severe that even the most virtuous person could
not bear it. For Aquinas, virtuous moderation of the passions is
not synonymous with suppression of the passions. Even Christ
himself began to sweat drops of blood at the mere thought of
having to die on a cross (Luke 22:44). Nonetheless, there is
something about the nature of pain that seems less voluntary
than the nature of sorrow, even if neither of them can be
described as fully subject to one’s will.
On Aquinas’s account, the passions do not have control over
the will, because the will always acts upon what the intellect
presents to it as good. But the passions play a powerful role in
39
Aquinas states (in STh I-II, q. 59, a. 4) that not all moral virtues are about the
passions, since justice is the virtue that perfects the will. Yet, in the next article (q. 59,
a. 5), he highlights the close relationship between justice and the passions, insofar as an
increase in the perfection of justice will lead to an increase in joy, which “overflows”
into the sensitive appetite. On the importance of the passions for the moral life in
Aquinas’s thought, see Servais Pinckaers, “Reappropriating Aquinas’s Account of the
Passions,” in The Pinckaers Reader, ed. John Berkman and Craig Steven Titus
(Washington, D.C.: The Catholic University of America Press, 2005), 273-87; see also
Eleonore Stump, “The Non-Aristotelian Character of Aquinas’s Ethics: Aquinas on the
Passions,” Faith and Philosophy 28 (2011): 29-43.
40
STh I-II, q. 56, a. 4.

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human action, precisely because they can influence what the
intellect perceives to be good.41 As Aquinas describes this indirect influence, a passion can distract the soul’s attention away
from something it might otherwise perceive as good and
worthwhile. “In the operations of the soul,” he writes,
certain attention is required, and if it is strongly focused on one thing, then
less attention is given to another. Thus, by a kind of distraction, when the
movement of the sensitive appetite is bolstered by some passion, there is
necessarily a remission or impediment of the rational appetite (which is the
will).42

It is difficult to focus on work when one’s stomach is growling.
While it might be possible to keep the hunger at bay for a while,
there will eventually come a point when the will decides that
eating is better than working. Those who suffer from migraine
headaches or chronic pain know that it can be virtually
impossible to accomplish other tasks when suffering such pain.
This usually leads to the decision to medicate one’s pain,
assuming that medication is available and that it works.
This is where the true moral significance of the passions lies,
and in this regard pain is paradigmatic. As Kevin White
observes, “The moral significance of all passions is due to their
capacity to attract, command, or absorb the soul’s attention,”
and “the theme of attention is most prominent in [Aquinas’s]
discussion of delight and pain.”43 The right response to the
passion of pain does not always involve what we would
consider heroic acts of virtue. The natural remedy for pain,
41
For Aquinas’s understanding of the relationship between intellect, will, and
appetite, see STh I-II, qq. 8-10. For a helpful exposition of Aquinas’s account, see
Eleonore Stump, Aquinas (New York: Routledge, 2003), 277-306.
42
STh I-II, q. 77, a. 1: “Tum quia in operibus animae requiritur quaedam intentio,
quae dum vehementer applicatur ad unum, non potest alteri vehementer attendere. Et
secundum hunc modum, per quandam distractionem, quando motus appetitus sensitivi
fortificatur secundum quamcumque passionem, necesse est quod remittatur, vel totaliter
impediatur motus proprius appetitus rationalis, qui est voluntas.”
43
Kevin White, “The Passions of the Soul,” in The Ethics of Aquinas, ed. Stephen J.
Pope (Washington, D.C.: Georgetown University Press, 2002), 111.

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Aquinas explains, is its counterpart: delight (delectatio) or joy
(gaudium).44 This can sometimes be achieved with such simple
solutions as having a good cry, sharing one’s grief with sympathetic friends, or taking a nap or a warm bath.45 He writes,
“Just as all bodily rest brings relief to all kinds of weariness
arising from nonnatural causes, likewise every pleasure brings
relief by mitigating all kinds of sorrow arising from various
causes.”46 Although pain and sorrow demand a response from
us—and some responses are morally good, while others are
morally bad—they are not in themselves evil. “It is a sign of
goodness,” Aquinas writes, “if a person, suspecting the presence
of something sad or painful, is in sorrow or pain on account of
this present evil.”47 When we perceive and seek to avoid something that is known to cause pain, this testifies to the goodness
of our created nature. When we feel sorrow at something evil,
this is due to the rectitude of our reason and will. It is a
testament to the fact that this is not the way things are supposed
to be.48
Pain is the enemy of our good.49 It distracts us, draws our
focus toward itself, and becomes an obstacle to moral and
44

For an illuminating survey of joy as an antidote to sorrow, drawing on a range of
historical figures, see Robert C. Roberts, “Joys: A Brief Moral and Christian
Geography,” Faith and Philosophy 36 (2019): 195-222.
45
These are addressed in STh I-II, q. 38 in aa. 1, 2, 3, and 5, respectively. There is an
oft-repeated but apocryphal quotation from Aquinas that “sorrow can be alleviated by
good sleep, a bath, and a glass of wine.” While Aquinas had no objection to drinking
wine in moderation, this line is not found in any of his written works.
46
STh I-II, q. 38, a. 1: “Sicut igitur quaelibet quies corporis remedium affert contra
quamlibet fatigationem, ex quacumque causa innaturali provenientem; ita quaelibet delectatio remedium affert ad mitigandam quamlibet tristitiam, ex quocumque procedat.”
47
STh I-II, q. 39, a. 1: “Sic igitur, supposito aliquo contristabili vel doloroso, ad
bonitatem pertinet quod aliquis de malo praesenti tristetur vel doleat.”
48
STh I-II, q. 39, a. 2.
49
An anonymous reviewer has correctly pointed out that pain per se is not an enemy
of our good. I should clarify, then, that there are two senses in which pain can be
considered an enemy of our good. In the first sense, pain can exceed its signaling
function and take on a life of its own that hinders progress in virtue. This is an
accidental feature of pain, however, so it does not belong to pain per se. In the second

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spiritual growth. This is true of both exterior pain and interior
sorrow. The suffering that results from pain or sorrow can
present an opportunity for growth in virtue, but the process is
not automatic. The biblical character of Job, for example,
struggled to see God’s goodness in the midst of profound grief
and loss. After losing most of his family and his possessions, he
laments with a monologue that begins, “Let the day perish on
which I was born” (Job 3:3). An overly pious interpretation of
this passage might suggest that Job’s passions simply got the
better of him. But Aquinas offers a different interpretation. He
explains, “So, Job indeed feels sad as a result of those adversities
which he suffered described above, otherwise the virtue of
patience would have no place in him.” Aquinas interprets Job’s
lament not as an unrestrained expression of raw passion but as
an entirely reasonable response to his sufferings. The fact that
Job expressed these words several days after his tragedy “clearly
shows that what he is going to say is said in accord with reason
which is not confused by sorrow. . . . In speaking he showed the
sorrow which he suffered and he showed patience.”50 Job made
virtuous use of his suffering, but suffering is not a virtue in and
of itself. As Eleonore Stump writes, “On Aquinas’s view
suffering is good not simpliciter but only secundum quid. . . . In
itself suffering is a bad thing; it acquires positive value only
when it contributes to spiritual well-being.”51 Pain and sorrow
may be conducive to virtue, but this is by no means guaranteed.
It is important to note that while pain can lead to growth in
virtue, it is always an obstacle to the good. This is not a
contradiction. It is in fact a central feature of virtue ethics. The
sense, pain, insofar as its existence is contingent upon the loss of humanity’s original
justice, is always a response to (or a reflection of) bodily corruption. In this second
sense, pain’s association with the loss of bodily integrity (which is opposed to our good)
is not merely contingent.
50
In Iob, c. 3, lect. 1 (trans. Brian Thomas Becket Mullady, O.P. [Lander, Wyo.: The
Aquinas Institute, 2016]).
51
Eleonore Stump, “Aquinas on the Sufferings of Job,” in Human and Divine
Agency: Anglican, Catholic, and Lutheran Perspectives, ed. F. Michael McLain and W.
Mark Richardson (Lanham, Md.: University Press of America, 1999), 201-2.

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virtue of courage is nurtured through repeated encounters with
adversity; the virtue of temperance is cultivated through repeated refusals to concede to the body’s impulses. But the
problem of pain bears special significance in this line of enquiry,
precisely because pain is at odds with what Aquinas states is the
greatest of all human pleasures: the contemplation of truth.
Pain is a hinderance to all learning and to all mental and
spiritual growth, because it burdens the soul and immobilizes
the movements of the soul and the body.52 However, the inverse
of this relationship also holds true. Since delight is the natural
antidote to sorrow (which is the interior apprehension of pain),
it follows that contemplation of the truth can reduce or
eliminate one’s pain. Aquinas argues that contemplation of the
truth can even reduce bodily pain. If this strikes us as odd, given
that contemplation is an intellectual activity and pain is a bodily
sensation, Aquinas anticipates this objection and responds: “In
the powers of the soul there is an overflow from the higher to
the lower; accordingly, the delight of contemplation, which is in
the higher part, overflows and as such mitigates the pain that is
in the senses.”53 It is because of this that “humans rejoice in
divine things and future blessedness, even in the midst of
tribulation.”54 He cites the example of the martyr Tiburtius,
who, when walking barefoot on burning coals, said, “I believe I
am walking on roses, in the name of Jesus Christ.”55
We must be careful here. We should not attribute to Aquinas
the view that contemplation of divine truths is a panacea for
bodily pain. While he does believe that it is possible for
52

STh I-II, q. 37, a. 2; and q. 37, a. 3.
STh I-II, q. 38, a. 5 ad 3: “Ad tertium dicendum quod in viribus animae fit redundantia a superiori ad inferius. Et secundum hoc, delectatio contemplationis, quae est in
superiori parte, redundat ad mitigandum etiam dolorem qui est in sensu.”
54
STh I-II, q. 38, a. 4: “Et ideo homines ex contemplatione divina et futurae
beatitudinis, in tribulationibus gaudent.”
55
Ibid.: “Et quod est amplius, etiam inter corporis cruciatus huiusmodi gaudium
invenitur, sicut Tiburtius martyr, cum nudatis plantis super ardentes prunas incederet,
dixit, videtur mihi quod super roseos flores incedam, in nomine Iesu Christi.
53

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contemplation to achieve this, he does not claim that it always
will or that this is something within reach of the average person.
Nor does he go as far as to say that failure to alleviate pain
through contemplation amounts to a moral failure. The experience of pain and sorrow is not sinful, and he points to the
examples of Job and even Jesus to underscore this point. Some
pain is unbearable and has the potential to stall any pursuit of
meaningful activity. In Elaine Scarry’s elegant description, “It is
the intense pain that destroys a person’s self and world, a
destruction experienced spatially as either the contraction of the
universe down to the immediate vicinity of the body or as the
body swelling to fill the entire universe.”56 The question, then,
is what we are to do when we cannot alleviate the experience of
pain through our own efforts. As I stated in the introduction,
the ERD direct the following: “Patients experiencing suffering
that cannot be alleviated should be helped to appreciate the
Christian understanding of redemptive suffering.”57 Ashley,
deBlois, and O’Rourke suggest that “the Christian tradition
holds that great spiritual good can come out of suffering when
it is joined to the sufferings of Jesus.”58 Given the foregoing
analysis, what is the meaning of “redemptive suffering”? What
might it mean to “join” one’s suffering to the sufferings of
Jesus?
IV. CHRIST’S PAIN ON THE CROSS AND THE PROBLEM OF
REDEMPTIVE SUFFERING
The medieval Scholastics were endlessly fascinated by the
topic of Christ’s ability to experience bodily pain.59 For many of
them, to deny that Christ felt any pain at all was a heretical
notion, since it suggested that he was not fully human. But to
claim that he experienced pain in the exact same way that we
56

Scarry, The Body in Pain, 35.
ERD, 61.
58
Ashley, deBlois, and O’Rourke, Health Care Ethics, 198.
59
See Donna Trembinski, “[Pro]Passio Doloris: Early Dominican Conceptions of
Christ’s Physical Pain,” The Journal of Ecclesiastical History 59 (2008): 630-56.
57

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do might imply that he was not free from sin, since pain belongs
to the curse of humanity’s fall described in Genesis 3. I cannot
adequately summarize the medieval debate here, but I want to
note that this is a serious theological problem and one that
reached its zenith in the high Middle Ages.60 For readers who
may find such questions obscure, trivial, or antiquated, I suggest
that these questions continue to haunt the human imagination
to the present day. Another way of framing the debate is this: Is
it right to say that Christ’s suffering lay solely in his abandonment by his Father, echoed in the cry, “My God, my God,
why have you forsaken me?” (Matt 27:46, echoing Ps 22:1)? Or
was his suffering primarily physical in nature? What is the
theological significance of his bodily pain? Was the pain he
experienced the same, or more or less severe than if the same
physical torture had been enacted on another human being?
These questions continue to have moral significance, insofar as
contemporary ethicists debate the relevance of Christ’s suffering
on the cross and the possibility of redemptive suffering for
those who experience severe and chronic pain. If we are to have
any idea what we mean when say that a person’s suffering can
be joined to Christ’s suffering, we must have some grasp of
what we mean by “Christ’s suffering.”
Aquinas, in solidarity with many Christian thinkers
throughout the centuries, maintained that Christ was fully
human and therefore experienced the human passion of pain.61
Although humanity lost its original integrity after the Fall, the
Son of God took on precisely this humanity, even as it exists in

60
For a useful overview of the medieval debate, see Kevin Madigan, The Passions of
Christ in High-Medieval Thought: An Essay on Christological Development (New York:
Oxford University Press, 2007); Paul Gondreau, The Passions of Christ’s Soul in the
Theology of St. Thomas Aquinas (Scranton, Penn.: University of Scranton Press, 2002)
provides a more faithful representation of Aquinas’s thought, however, and while its
focus is narrower, it serves in some ways as a corrective to Madigan’s volume.
61
Aquinas explicitly states that Christ experienced bodily pain (dolor) and sorrow
(tristitia) in STh III, q. 15, a. 5 and q. 15, a. 6, respectively.

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its postlapsarian condition.62 The humanity that Christ
voluntarily took on had what the Scholastics called the
“assumed defects,” and these were aspects of his human
nature.63 Aquinas’s belief that Christ experienced physical pain
sits in tension with his belief that Christ also experienced the
beatific vision throughout his entire life, from the moment of
his conception.64 One may point out that, according to Aquinas,
contemplation of divine truths overflows from the upper
powers of the soul into the lower powers of the sensitive
appetite, such that sensible pain is mitigated.65 If Christ
experienced the beatific vision—the very source of truth itself—
throughout his earthly life, it seems impossible that he should
have experienced sensible pain. Aquinas addresses this point:
By the power of Christ’s divinity, his beatitude was contained in his soul so
that it would not overflow into his body; otherwise, his passibility and
mortality would be abolished. For the same reason, the delight of
contemplation was kept in his mind so that it would not overflow into the
sensitive powers; otherwise, sensible pain would not have been possible.66

62
Interpreters of Aquinas have not payed adequate attention to the different ways in
which passions exist and operate within the various states of humanity (prelapsarian,
postlapsarian, and final beatitude). I address this problem in “The Passions of Christ in
the Moral Theology of Thomas Aquinas: An Integrative Account,” New Blackfriars 99
(2018): 458-80.
63
STh III, qq. 14 and 15.
64
STh III, q. 9, a. 2.
65
This idea can be found in many places before and after Aquinas. In the fifteenth
century, Julian of Norwich would write, “And if we were in all the pain that heart can
think and tongue can tell, if we could at that time see His fair, blessed face, all this pain
would not bother us. Thus is this blessed sight the end of all manner of pain to the
loving soul, and the fulfillment of all manner of joy and bliss” (Revelation 72 [The
Complete Julian of Norwich, ed. Fr. John-Julian, O.J.N. (Brewster, Mass.: Paraclete
Press, 2009), 333]).
66
STh III, q. 15, a. 5, ad 3: “Ad tertium dicendum quod, sicut supra dictum est,
virtute divinitatis Christi dispensative sic beatitudo in anima continebatur quod non
derivabatur ad corpus, ut eius passibilitas et mortalitas tolleretur. Et, eadem ratione,
delectatio contemplationis sic continebatur in mente quod non derivabatur ad vires
sensibiles, ut per hoc dolor sensibilis excluderetur.”

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While Aquinas wants to acknowledge that Christ was not like
us—for how could he be, if he is God incarnate?—he also wants
to acknowledge that he was very much like us, in that he experienced the full range of bodily passions, not least of which
was pain.
Aquinas’s claims about Christ’s bodily pain did not stop
there, however. In contrast to many of his Cistercian and Franciscan contemporaries, Aquinas (along with other Dominican
theologians, including Albert the Great) claimed that the pain
Christ experienced on the cross was the worst pain any human
being has ever experienced.67 This claim pertains not just to the
psychological suffering that accompanied his bodily pain, but to
the bodily pain itself. This is not only due to the severity of his
treatment by the Romans. Aquinas cites, among other reasons,
the fact that Christ had the most perfect human constitution
and therefore had the most acute sense of touch. The bodily
pain he felt was more severe than that which any other human
would experience while undergoing the same physical torture.
As Donna Trembinski explains, the Dominicans were not only
trying to combat the “Manicheans” (or Cathars) who denied
Christ’s humanity, they were also reacting against emerging
trends in orthodox expressions of piety:
In the thirteenth century new modes of affective devotion to God were developing that focused upon how an individual’s experience of suffering could
bring one closer to God through the process of imitatio Christi. In the twelfth
century Bernard of Clairvaux had taught that one could approach God
through humility and that contemplation of Christ’s suffering humanity was
more helpful to the laity than devotion to the divinity of the Godhead. In the
first decades of the thirteenth century Francis of Assisi suffered captivity and
illnesses, culminating in his experience of the stigmata, all of which allowed
him a feeling of unprecedented closeness to God. Other pious people soon
followed in the footsteps of these pioneers, using bodily suffering to approach
and experience an affinity with God in a new way.68

67
68

STh III, q. 46, a. 6.
Trembinski, “[Pro]Passio Doloris,” 653.

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For a Dominican like Aquinas, pain (like any of the passions)
can be made use of virtuously and spiritual benefits may be
reaped therefrom. But it does not provide any direct, mystical
access to holiness via the suffering of Christ. To assume as much
would veer too close to the error of Pelagianism, or a belief that
we can earn our salvation through our suffering in the same way
Christ earned favor with God through his. We find this message
also in Dominican narratives and Dominican art, which “seem
to suggest that Christ’s suffering can be witnessed but never
experienced.”69 Whatever it might mean for us to participate in
Christ’s suffering, it does not mean that we fully endure what
he endured, or that our suffering can merit what his has
merited.
In the entry for “Pain” in the New Catholic Encyclopedia,
Maria Teresa Russo writes,
While remaining a mystery, pain is one of the ways through which Christ has
shown his radical love for man. It also becomes an appeal to every suffering
person to somehow integrate themselves into this love. Through this perspective, pain acquires a richness of meaning as something that was accepted
by the Son of God when he chose to share in the fullness of human
existence.70

Of course, the difficulty lies in articulating what it means to
“somehow integrate” oneself into Christ’s love and, more specifically, his pain. In his apostolic letter Salvifici doloris, Pope
John Paul II utilizes a robust grammar of redemptive suffering
and participation, but even his account seems to suggest that it
is Christ’s suffering that gives new meaning to all human suffering. Commenting on the New Testament’s perspective on
suffering, he writes,
The very participation in Christ’s suffering finds, in these apostolic
expressions, as it were a twofold dimension. If one becomes a sharer in the
69

Ibid., 655.
Maria Teresa Russo, s.v. “Pain,” New Catholic Encyclopedia Supplement 20122013: Ethics and Philosophy, ed. Robert L. Fastiggi (Farmington Hills, Mich.: Gale,
2013), 1118.
70

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sufferings of Christ, this happens because Christ has opened his suffering to
man, because he himself in his redemptive suffering has become, in a certain
sense, a sharer in all human sufferings. Man, discovering through faith the
redemptive suffering of Christ, also discovers in it his own sufferings; he
rediscovers them, through faith, enriched with a new content and new
meaning.71

On this account, it seems that one’s own pain or suffering does
not efficaciously lead to redemption, at least not in the same
way we would describe the work of the sacraments. Rather, the
power of suffering is only to be found in one’s recognition of its
meaning, set within in the grand scheme of God’s redemptive
plan for humanity, which has been made available to all human
beings.
In response to the recommendations of the ERD and contemporary Catholic health-care ethicists, Aquinas would likely
suggest that we can join our suffering to Christ’s by contemplating his unique sacrifice. Our pain may be conducive to
this effort, insofar as it allows us to relate (in some small
measure) to the pain that Christ endured on our behalf. But
then again, it might not. Our pain may be too severe, too
distracting, to allow for such contemplation. In such cases,
medicating the pain may be the route that is more conducive to
virtue.72 This remains true even in some cases where medication
results in unconsciousness. If we remember that pain has no
value in itself, then we can also recognize that there may be
situations where pain is so severe that the only good left to
pursue is the elimination of that pain. As Gilbert Meilaender
writes,
Remembering that one of the goals of medicine is relief of suffering, I believe
that sedation to unconsciousness for such a patient, even if rarely needed, can
be good medical practice. In such straitened circumstances there is no need

71

John Paul II, Salvifici doloris, 20.
For some clear and helpful Thomistic guidelines for the clinical treatment of pain,
especially in the context of palliative care, see Jason T. Eberl, Thomistic Principles and
Bioethics (New York: Routledge, 2006), 104-11.
72

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for, and little to be gained from, attempting to distinguish an intention to
palliate symptoms (with the foreseen effect of unconsciousness) from an
intention to produce unconsciousness.73

If this is the route we choose to take, then we should be honest
about what we are doing and what we are trying to accomplish.
Of course, even if we are able to alleviate our pain (dolor),
this does not always protect us from the possibility of sorrow
(tristitia). The cancer patient who is able to mitigate physical
pain through powerful painkilling drugs will still feel the profound sadness of a diminished life. This is why I can concur
with Ashley, deBlois, and O’Rourke when they say, “The opportunity to use suffering as a means of spiritual growth is not
destroyed if pain-killing drugs are used.”74 Christians who take
medication for pain are not somehow circumventing a spiritual
process. Those with unbearable pain know that it can be an
obstacle to their relationship with God and preclude any
meditation of divine truths. While the choice to take pain
medication should not be treated flippantly, it is often the
virtuous choice.
CONCLUSION
I have certainly not adequately addressed all the questions
raised in this article. Nevertheless, I believe there are three
observations we can take away from the preceding analysis.
First, medicating pain is always a moral choice. There is no
morally neutral choice to medicate or not medicate one’s pain,
and this is true whether one chooses to take an ibuprofen tablet,
to refuse a morphine injection, or to receive an epidural. Our
decision to use pain medication ought to be informed by our
understanding of what it means to live virtuously, and, as
Aquinas reminds us, for Christians this means that all of our
actions are oriented toward the contemplation of divine truth.
73
Gilbert Meilaender, Bioethics and the Character of Human Life: Essays and
Reflections (Eugene, Ore.: Cascade, 2020), 128.
74
Ashley, deBlois, and O’Rourke, Health Care Ethics, 198.

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In any given instance, there is no obvious answer to the
question, “Should we medicate this pain?” Other virtues,
namely prudence and especially charity, will guide this decision.
Second, the suffering we experience in pain is not privileged.
In the vast majority of cases, the bodily pain we experience—
chronic, acute, or otherwise—should not be mistaken for
stigmata. While it is possible for pain to draw us closer to God
(and perhaps even analogously to “participate” in the sufferings
of Christ),75 it is equally possible for pain to serve as an
obstacle—an obstacle to the contemplation that is necessary for
those seeking to live a virtuous life or die a virtuous death. It is
true that Christianity has a long tradition of using this
participation language to describe the relationship between
personal suffering and the suffering of Christ.76 I do not deny
that God can use a person’s pain in a mystical way and imbue it
with spiritual significance that transcends intellectual scrutiny. I
simply do not think that this is the language that we should use
when providing normative or pastoral guidance to those who
suffer from pain. The question at stake here, helpfully articulated by Nicholas Wolterstorff, has to do with the possibility of
any inherent (i.e., noninstrumental) meaning in pain:
One finds cases in the Christian tradition in which a person describes herself
as in her pain participating—in a way I do not profess to understand—in

75

In Col 1:24, St. Paul writes, “I am now rejoicing in my sufferings for your sake,
and in my flesh I am completing what is lacking in Christ’s afflictions for the sake of his
body, that is, the church” (NRSV). Aquinas notes that there are several ways to read this
text, including the heretical interpretation that Christ’s passion was not sufficient for
our redemption. Among the plausible interpretations he commends is the idea that the
suffering of the saints and martyrs contributes a (God-ordained) portion to the share of
merit that has been allotted to the Church, of which Christ is the head and whose merits
are infinite. See Super Epistolas S. Pauli lectura, vol. 2, Super Epistolam ad Colossenses
lectura, ed. Raphael Cai (Turin: Marietti, 1953), 61.
76
For an account of the origins of this tradition, see Judith Perkins, The Suffering
Self: Pain and Narrative Representation in Early Christianity (New York: Routledge,
1995); On medieval developments of this tradition, see Esther Cohen, The Modulated
Scream: Pain in Late Medieval Culture (Chicago: University of Chicago Press, 2010).

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Christ’s pain. One finds hints of this way of experiencing pain already in the
New Testament writings of St. Paul; it is also how the martyrs sometimes
spoke. . . . For what is excellent in such cases is neither the virtuous way in
which the sufferer endures the pain nor the excellence of character that the
pain yields.77

Perhaps what we need is further theological and philosophical
exploration into the meaning of this “participation” in Christ’s
suffering.
Finally, while I am well aware that I have not offered a
philosophical argument for the claim that pain should be
understood as a passion of the soul (which requires belief in a
rational soul, as well as other philosophical commitments), I
have at least suggested reasons why Christians ought to hold
this belief. One important upshot of this belief is that if pain is a
passion of the soul then it cannot also be a vital sign.78 In other
words, it is not simply the case that we have historically been
unable to quantify pain. Rather, we will never be able to
quantify pain because it is not the sort of thing that can be
quantified. It does not belong to the same genus as body
temperature, pulse, respiration rate, and blood pressure. If pain
is a passion, then by definition it is the subject of the moral
virtues. This means that there is such a thing as virtuous pain
management. To assert that pain is a vital sign is to undermine
the idea of virtuous pain management, because it presupposes
that pain is an objective bodily measurement that ought to be
77

Nicholas Wolterstorff, “The Place of Pain in the Space of Good and Evil,” in
Coakley and Shelemay, eds., Pain and Its Transformations, 418.
78
Vital signs are objective measurements of the body’s most basic functions. In
contemporary medicine, the four primary measurements are body temperature, blood
pressure, pulse, and breathing rate. Others, including pain, have been suggested as
additional vital signs, but these remain contested. See the Joint Commission’s document,
“Pain Assessment and Management Standard for Joint Commission Accredited Health
Care Organizations,” found at https://www.jointcommission.org/-/media/tjc/documents/
corporate-communication/pain-management-standards-and-responses-to-myths-final-feb
-2020.pdf. For a fascinating exploration of recent developments in pain studies (away
from pain as the fifth vital sign), see Alix Spiegel and Hanna Rosin, “The Fifth Vital
Sign:
Invisibilia:
NPR,”
Season
5,
accessed
August
15,
2021;
https://www.npr.org/2019/03/06/700743108/the-fifth-vital-sign.

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regulated by quantifiable norms. By resisting this idea, Christians bear witness to the biblical pattern of creation, fall, and
redemption, insofar as they acknowledge that bodily pain is a
postlapsarian response to the body’s corruption. Christians
believe that the four human vital signs recognized in contemporary medicine would exist even if humanity had never fallen;
not so for pain. Pain is a passion, and in this “vale of tears” pain
(dolor) and sorrow (tristitia) will always be part of what it
means to be human.79

79
I am grateful to Jason Eberl, Gerald McKenny, Gilbert Meilaender, Jean Porter,
and Eleonore Stump for their helpful comments and suggestions on an earlier draft of
this article. I also wish to thank my colleagues at Aquinas Institute of Theology, the
graduate students in the Saint Louis University philosophy department, and members of
the Society of Christian Ethics who were present for various talks related to this article.
Their insightful comments and questions helped me sharpen my thinking. Additional
improvements to the text were made in light of the suggestions provided by Fr. Andrew
Hofer, O.P., and an anonymous reviewer for the Thomist. Any mistakes or deficiencies
that remain are, of course, my own.

The Thomist 86 (2022): 119-37

THE PRINCIPLE OPERARI SEQUITUR ESSE
IN KAROL WOJTYŁA’S STUDY OF PERSON AND ACT
PIOTR STANISŁAW MAZUR
Jesuit University Ignatianum
Krakow, Poland

K

AROL WOJTYŁA drew deep and far-reaching conclusions from the Scholastic principle that acting follows
upon being (operari/agere sequitur esse). If one does not
consider this principle, the idea underlying his most important
work, Person and Act, is incomprehensible and even meaningless, yet it was omitted in the English translation of this study.1
This article demonstrates how Wojtyła interpreted this principle
and used it to explain the relationship between the person and
his action.
Referring to the thought of St. Thomas Aquinas, Wojtyła
treats action as a manifestation of a subject’s dynamism and as
secondary to the act of existence. The analysis of an act as a

1
Małgorzata Jałocho-Palicka, “Thomas Aquinas’ Philosophy of Being as the Basis for
Wojtyła’s Concept and Cognition of Human Person,” Studia Gilsoniana 3(2014),
127-29, shows that the 1979 English translation of this work (The Acting Person, ed.
Anna-Teresa Tymieniecka, trans. Andrzej Potocki [Boston: D. Reidel, 1979]), in
contrast to the original, makes no reference to either the OSE principle or the Thomistic
understanding of esse. As a result, the English-speaking reader can only guess that the
study somehow refers to this principle, while in fact Wojtyła uses and interprets. This
translation error is avoided in the most recent translation (Karol Wojtyła, Person and
Act and Related Essays, trans. Gregory Ignatik [Washington, D.C.: The Catholic
University of America Press, 2021]) and the more recent analyses of Wojtyła’s thought;
see Miguel Acosta and Adrian J. Reimers, Karol Wojtyła’s Personalist Philosophy:
Understanding Person & Act, (Washington, D.C.: The Catholic University of America
Press, 2016), 139 and 225. However, this demonstrates that it is necessary to conduct
further analyses of this aspect of Wojtyła’s thought.

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proper human action based on this relation allows him to reveal
the nature and the manner of the existence of man as a personal
being.2 His considerations are an exemplification of the validity
of this principle; at the same time, they offer its theoretical
explanation and justification.
I. THOMISTIC FOUNDATIONS
Aquinas frequently refers to the Scholastic formula
operari/agere sequitur (ad) esse (OSE).3 In his work this formula
2
That is why the claim that Wojtyła modifies classical metaphysical anthropology,
which moves from being to act, and replaces it with new anthropology that moves from
act to being is imprecise (cf. Juan M. Burgos, “The Method of Karol Wojtyła: A Way
between Phenomenology, Personalism and Methaphysics,” in Phenomenology and
Existentialism in the Twentieth Century, ed. Anna-Teresa Tymieniecka [Dordrecht:
Springer, 2009], 2:109). In Wojtyła’s study, the basis for analysis is the ontic
relationship between the person and an act, which is indicated by metaphysics. Knowing
the person through his acts is justified if we assume that a being’s action is an expression
and manifestation of its existence. Thomistic anthropology moves from the subject
(substance) to his acts (actions) in its presentation of man, while in the cognitive aspect
it analyzes acts in order to define the nature of the subject. Wojtyła focuses on cognitive
analyses, but he refers to both these aspects. He uses the tools developed in
phenomenology precisely to grasp and describe the relationship between the moral
action (act) and the person as its subject, given in the first-person experience. The
problem of the relationship between Thomism and phenomenology in Wojtyła’s
thought is addressed in numerous works, including Jerzy W. Gałkowski, “The Place of
Thomism in the Anthropology of K. Wojtyła,” Angelicum 65 (1988): 181-94; Jameson
Taylor, “Beyond Nature: Karol Wojtyła’s Development of the Traditional Definition of
Personhood,” The Review of Metaphysics 63 (2009): 415-54; Edward Barrett, Persons
and Liberal Democracy: The Ethical and Political Thought of Karol Wojtyła/Pope John
Paul II, (Lanham, Md.: Lexington Books, 2010).
3
Aquinas’s understanding of the OSE principle has not yet been systematically
analyzed. However, many authors make reference to it. It is explicitly mentioned by
Karol Wojtyła himself in the article “The Person: Subject and Community,” The Review
of Metaphysics 33 (1979): 273-308. Jameson Taylor (“Beyond Nature”) indicates
Wojtyła’s Thomistic understanding of this principle. The principle is also used to
analyze various problems: John Haldane, “Some Metaphysical Presuppositions of
Agency. Agere sequitur esse: Acting follows upon being,” The Heythrop Journal 35
(1994): 296-314; John F. Crosby, The Selfhood of the Human Person (Washington,
D.C.: The Catholic University of America Press, 1996), 260; John Laird, “Act-Ethics
and Agent-Ethics,” Mind n.s. 55 (1946): 113-32; John Haldane, The Philosophies of

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takes the form of reasoning that leads to the primacy of
existence over action (“existence precedes action by nature”).4 If
a being acts and accomplishes the acts proper to it, this means
that this being exists. Although Aquinas does not reflect on this
relationship in a systematic manner, he repeatedly refers to it,
under various formulations, when discussing a variety of issues.5
Some of these statements, such as “to act is the result of a being
which is in act,”6 “a thing operates in accordance with its nature
[quod est],”7 “for nothing can operate but what is actual,”8 can
be reduced to a basic Scholastic formula. Therefore, the relationship between action and existence, which Aquinas treats in a
restricted and schematic way, requires a more complex and
precise analysis.
For Aquinas, existence and action are not abstract concepts
but facts related to each other and given in everyday experience.
That is why he always puts them in the context of a particular
being (“act belongs to that which exists”).9 They are this being’s
different acts (perfections). Existence is a being’s act taken as a
whole, whereas action is the realization of one of its potencies.
Mind and Nature, in Recovering Nature: Essays in Natural Philosophy, Ethics, and
Metaphysics in Honor of Ralph McInerny, ed. Thomas Hibbs and John O'Callaghan
(Notre Dame, Ind.: University of Notre Dame Press, 1999), 37-51; J. Thomas Petri,
“Altered Nuclear Transfer, Gift, and Mystery: An Aristotelian-Thomistic Response to
David L. Schindler,” The National Catholic Bioethics Quarterly 7 (2007): 729-47;
Carlos A. Casanova and Ignacio Serrano Del Pozo, “An Assessment of the Being and
Operation of Mary’s Marriage, The Thomist 83 (2019): 31-55.
4
STh III q. 34, a. 2, ad 1. All quotations from the Summa theologica are taken from
Summa Theologica, trans. the Fathers of the English Dominican Province (New York:
Benziger Brothers, 1947).
5
Aquinas’s concept of the relationship between existence and action is not limited to
single statements but is inscribed in all of his metaphysics and anthropology; however,
this cannot be discussed here more fully.
6
ScG III, c. 69. All quotations from the Summa contra gentiles, book 3, are taken
from Summa contra gentiles, book 3, trans. Vernon J. Bourke (New York: Doubleday &
Company, 1956).
7
Q. D. De Anima, a. 14. All quotations from the disputed question De anima are
taken from The Soul, trans. J. P. Rowan (St. Louis: B. Herder, 1949).
8
STh I, q. 75, a. 2.
9
ScG II, c. 50. All quotations from the Summa contra gentiles, book 2 are taken
from Summa contra gentiles, book 2, trans. James F. Anderson (New York: Doubleday
& Company, 1956).

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Aquinas understands action as the emanation of an existing
being which, through the emergence of a particular act, becomes the cause of something. This being as a substantial subject
acts through its potencies (powers), which are its accidents.10
Accidents exist or act not independently, but only to the extent
that their subject exists. Therefore, acting is attributed to a subject and not to its accidents (“acting belongs not to accidents but
to subjects”).11
According to Aquinas, every being acts in the manner proper
to it, accomplishing its acts through its nature (“the proper
operation of a thing depends on its nature”).12 Nature understood in this way is the very essence of a being insofar as it is
the source of a determined (specific) action. Nature allows a
being to act in a particular manner and defines the limits of this
action. At the same time, it also indicates a given being’s
membership in a particular species (e.g., a human being), and
determines the place this being occupies among other beings.
Therefore, it can be reasonably claimed that an individual being
(e.g., John) acts thanks to his species affiliation (mankind;
“nothing acts except in keeping with its species”),13 and it is not
possible for him to go beyond what is proper to his species
(“nothing acts outside its species”).14 Particular characteristics of
action—being mediated by nature and species affiliation—allow
the subject of this action to be identified. According to Aquinas,
the substantial form is the factor responsible for determining a
being’s essence, nature, and species affiliation. This form is the
cause of the existence of a being and its acting. Therefore, he
explicitly states that a particular being acts through its form
(“every agent acts through its form”).15 As a result, as John
10

See STh I, q. 77, a. 1, ad 3 and 4.
III Sent., d. 28, q. 1, a. 1 (translation from Commentary on Sentences in the
Aquinas Institute’s “Aquinas Opera Omnia” project [https://aquinas.cc/la/en/
~Sent.III.D28.A1.C.2], accessed 8/3/2020). In Q. D. De Anima, a. 14, he expresses it as
follows: “things that exist of themselves have an operation of their own.”
12
ScG III, c. 84.
13
ScG II, c. 49.
14
STh III, q. 79, a. 2, obj. 3.
15
STh I, q. 42, a. 1, ad 1.
11

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Wippel observes, both acting and its results bear some similarity
to the form of the acting being.16
Aquinas uses the Aristotelian theory of act and potency and
the relationship between existence and action to formulate a
comprehensive concept of our cognition of human beings. A
being acts through powers which are directed at their proper
objects.17 These powers as potencies are accidents of the soul
which is their source and act. “The soul by its very essence is an
act.”18 Since the act and the potency belong to the same category of being, analysis of the nature of the objects toward which
the particular acts of a substance are directed allows the nature
of these acts to be determined. By analyzing the nature of acts,
it is possible to know the nature of the powers emanate them.
These powers indicate their proportional subject-substance.
Thus, from the fact that the objects of mental acts are immaterial, Aquinas concludes that the essence of the soul is spiritual.19
II. THE WAY OF INTERPRETATION OF THE OSE PRINCIPLE
The relationship between human action and its subject
occupies a central position in Wojtyła’s analyses. This relationship results from the metaphysical grounding of man. Therefore, a correct analysis of it requires taking into account the
basic principles of being that are indicated in Thomistic metaphysics. According to Wojtyła, the principle of primacy of
existence over action plays a fundamental role. “The first,
16

See John F. Wippel, Metaphysical Themes in Thomas Aquinas II (Washington,
D.C.: The Catholic University of America Press 2007), 171; cf. STh I, q. 4, a. 3.
17
“A power as such is spoken of in relation to an act. Hence a power must be
defined by its act, and powers in turn distinguished from one another inasmuch as their
acts are different. Now acts derive their species from their objects” (Q. D. De Anima, a.
13).
18
STh I, q. 77, a. 1.
19
See STh I, q. 75, a. 2. Wojtyła develops this issue in his earlier work:
Considerations on the Essence of Man [Rozważania o istocie człowieka], trans. John
Grondelski (Lublin: Polskie Towarzystwo Tomasza z Akwinu, 2016). In order to define
nature and the way in which man exists as a subject, Wojtyła in Person and Act examines
the act in detail as one of the most important manifestations of human activity.

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elementary understanding of the relationship that occurs
between action and the acting subject is expressed in . . . the
phrase ‘operari sequitur esse’.”20 He quotes this Scholastic
principle several times,21 and not in order to state the obvious
or to give a more erudite character to his reflections. It primarily plays an explanatory role: from the metaphysical perspective, it explains the relationship between the person and his
act. It thus makes possible Wojtyła’s detailed analyses, and
justifies them. The OSE principle is an indispensable interpretative key for understanding the study of the person and his act.
According to Wojtyła, the classical OSE principle should be
understood as a relationship of a metaphysical nature that can
be interpreted in an existential or essential way. It is an
expression of the ontic (“existential”) relationship between
action and existence in the sense that “in order to act, it is first
necessary to exist.”22 The fact that existence precedes and, in a
certain way, determines action is obvious to Wojtyła, but it
needs further clarification. Man as subject is the keystone of
existence and action, both of which have a certain independence. Existence is not the same as action. Wojtyła emphasizes
the actual nonidentity of the existence and action of the same
being (man), and opposes treating action as a simple extension
of existence. Existence is not action, but action is not existence
either. Action, if it takes place, has a certain existence which
“flows from and is subsequent to the existence of man; it is its
consequence or effect.”23 Due to its accidental character, this
action is not necessary for existence.
20
Karol Wojtyła, Osoba i czyn oraz inne studia antropologiczne [Person and Act and
Other Anthropological Studies] (Lublin: Towarzystwo Naukowe KUL, 2011), 130. All
translations from this work are my own.
21
Wojtyła directly refers to the OSE principle in the first edition of Osoba i czyn
[Person and Act] (Krakow: Polskie Towarzystwo Teologiczne, 1969), 75, 85, 86, 157. In
the English edition the phrase was simply translated, without any indication that it is a
Scholastic principle, or that Wojtyła regards it precisely as such.
22
Wojtyła, The Acting Person, 82.
23
Ibid. Cf. Osoba i czyn [Person and Act], 130: “The existence of acting is ordered
and, at the same time, subordinated to the existence of man in an accidental manner, as
accidens.”

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125

Wojtyła develops his concept of the person and his act
within the framework of existential Thomism, which claims the
primacy of existence as the act of being over its essence. He
seems to make a deliberate effort to show that the OSE
principle takes into account both the existential and the
essential aspects of the relation between existence and action.
The existential perspective allows the conclusion that existence
and action are interdependent, but it does not show what this
relationship consists of and what ultimately results from it.
Thus, it seems necessary to interpret the OSE principle in the
“order of essence.” Here the relationship between an existing
subject and its action comes to the fore. “Our principal phrase
‘operari sequitur esse’ . . . allows us to perceive and establish the
relationship that occurs between action and the acting
subject.”24 The change in the perspective of analysis from existential to essential shifts attention from existence to its subject
because existence is always the existence of someone. This reveals a far-reaching similarity between the subject as the source
of action and this action itself. For Wojtyła, the word “sequitur,” which he understands as “coherence,” is the expression of
this similarity between the acting person and action in the OSE
principle. He does not specify its meaning but rather observes
that it is expressed in nature, which links the subject to its
dynamism and expresses their mutual dependence. This
coherence seems to have been aptly captured by Robert
Spaemann in his explanation of the OSE principle: “Any entity
in nature displays what it is by what it does, by its manner of
expressing itself.”25 Coherence here implies not only a relationship but also a kind of relevance and similarity between the
acting subject and his action. Thanks to this similarity, the
acting subject manifests himself through his action, and the
action indicates what or who the acting subject is. Therefore,
24

Wojtyła, Osoba i czyn [Person and Act], 131. Cf. The Acting Person, 82-83: “The
existential relation between action and being with we are here concerned allows us . . .
brings to light the relation between the acting process and the acting subject.”
25
Robert Spaemann, Persons: The Difference between ‘Someone’ and ‘Something’,
trans. Oliver O’Donovan (Oxford: Oxford University Press, 2017), 12.

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the peculiar interconnection between an act and the person
cannot be understood in isolation from the OSE principle.
From Wojtyła’s interpretation of the OSE principle, it
follows that the proper way to know the person is through his
act. Some accused Wojtyła of proclaiming the primacy of action
over the subject of this action (person). Defending himself
against this accusation, he states that the concept of the
transcendence of the person in his act protects his study from
such an interpretation and adds that
on the basis of this primacy we can see the basis for affirming the personal act
of existence at the root of all the dynamisms of the person, thus, above all, of
this strictly personal dynamism, which is the very act.26

He is, therefore, consistent in his claim that the relationship
between the person and an act is closely related to the relationship between the orders of existence and action of that
person as a subject. He is also consistent in his claim that action
is secondary to existence because existence (esse) is the source
of “all the dynamisms of the person.”
III. ACT BELONGS TO THAT WHICH EXISTS
For Wojtyła, man is a dynamic being, and as such moves in
his subjective existence from potential states (potencies) to
actual (perfecting) states. This relative (because it assumes a
specific nature of the subject) actualization is called “becoming”
(fieri). Man’s dynamism is expressed in experiencing both what
is happening in man (pati, “happening”) and what man is doing
(agere, “act”).27 He experiences himself as the subject of what is
26
Karol Wojtyła, “Słowo końcowe [The Final Word],” Analecta Cracoviensia 5
(1973): 257.
27
The division of dynamism into what is happening in man and what man is doing
proposed by Wojtyła corresponds to Aquinas’ distinction between a human action (actus
humanus) and an act of a human being (actus hominis). It is not, however, identical with
Aristotle’s distinction between action and sensation, although Wojtyła consciously terms
them agere and pati, (which is omitted in the English translation of The Acting Person).
However, he needs Aristotle’s distinction to show that these are dynamisms in some

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happening in him and as the cause of what he does. In
experiencing what is happening in him, man expresses himself
as a subject; when he acts, he experiences his own agency. Both
these experiences (being a subject and being an agent) are
grounded in ontic subjectivity (suppositum).
It is in the subject as a being that every dynamic structure is rooted, every
acting and happening. It is given as real, actually existing, being, the manbeing that actually exists and hence also “really” acts.28

It is this ontic subjectivity (strong) and not mental subjectivity
(weak) that Wojtyła has in mind when he points to the subject
of existence and action and analyzes the relationships between
them.29 The same subject exists and acts, but the subject is
different from his acts, namely, existence and action. In order to
explain correctly the relationship between these acts, Wojtyła
refers explicitly to Aquinas, according to whom
Existence . . . is the first act [actus] of every being, that is the first and
fundamental factor establishing its dynamism. The whole dynamism that
consists in action and in the becoming that takes place in a dynamic subject is
secondary to that dynamism: “operari sequitur esse.”30

Thus, Wojtyła treats existence as an act that is the basic and
primary source of the whole dynamism of human existence,
while he treats action as an act-dynamism that derives from it.
respects opposing but at the same time mutually conditioning and complementing each
other in others, precisely as action and sensation. Thus what man is doing is an active
dynamism, while what is happening in man is a passive dynamism. See Wojtyła, The
Acting Person, 61-62.
28
Ibid., 72.
29
See Acosta and Reimers, Karol Wojtyła’s Personalist Philosophy, 138-39. For more
on Wojtyła’s understanding of subjectivity as suppositum, see Grzegorz Hołub, “Karol
Wojtyła on the Metaphysics of the Person,” Logos i ethos 39 (2015): 97-115;
http://dx.doi.org/10.15633/lie.1538, accessed Jan. 22, 2020.
30
Wojtyła, Osoba i czyn [Person and Act], 122. Cf. The Acting Person, 73: “Coming
into existence may, indeed, be seen as the first act of every being, that is, the first and
fundamental factor establishing its dynamism. The entire dynamism of man’s
functioning which consists in the acting of, and happening in, the dynamic subject
simultaneously proceeds from (but also enacts) the initial dynamism due to which a
being exists at all.”

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Like Aquinas, he thinks that from the genetic perspective the
existence of the subject precedes its action.31
In the analysis of the relationship between existence and
action proposed by Wojtyła, the subject plays a key role. Existence is always somebody’s and action is always somebody’s, so
they belong to some subject. The subject binds the ontic
relationship of these realities and is an indispensable element in
explaining them. The source of subjective dynamism lies in
existence. Existence makes a particular being a “dynamic subject.” “The dynamism that comes from existence, from esse,
entails the dynamism proper to an operari.”32 At the same time,
this whole dynamism is actualized in the subject, because “on
the ground of human suppositum” takes place a “synthesis of
acting and happening.”33 For Wojtyła, an act is a special form of
dynamism: it is an action whose subject and autonomous agent
are simultaneously an individual human being. This kind of
action indicates that the human subject is unique, is the person.
For Wojtyła, it is obvious that, since man is the person, his
existence is personal, and not only individual; similarly, human
dynamism—actions and becomings—are also personal.34 Consequently, human dynamism, especially the dynamism in which
agency is revealed, is for him a manifestation of the personal
subject.
IV. THINGS THAT EXIST OF THEMSELVES HAVE AN OPERATION
OF THEIR OWN
According to Wojtyła, “the manifestation and actualization
of the dynamism proper to man” is the experience of “I may but
I need not.”35 Against the background of the experience of the
subjective potency of action (“I can”) and, at the same time, a
31

See Wojtyła, Osoba i czyn [Person and Act], 122.
Ibid. 24. Cf. The Acting Person, 75: “The dynamism derived from the actual
existence has its consequence the dynamism pertaining to activity.”
33
Wojtyła, Osoba i czyn [Person and Act], 124.
34
See ibid., 123.
35
Wojtyła, The Acting Person, 100.
32

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lack of external obligation (“I don’t have to”), the freedom of
the human subject, whose act of wanting is the source of action,
is revealed. Wanting manifests itself in the light of, on the one
hand, what the subject can do and, on the other hand, what the
subject does not have to do. Wojtyła explains this experience by
referring to the theory of act and potency. He emphasizes that
action as an act comes from potency which is proportional to it
and which is “inherent and that ceaselessly pulsates in the
subject, and which comes to the surface in one or the other
form of the subject’s dynamizations.”36 This subjective potency
that is “allowing man to want” is the will.37 The will is the
power of wanting good and, at the same time, the power that
chooses one good from among other goods. If, therefore, man
wants something, he wants it through his will, and similarly he
makes choices through his will, whereas he performs other acts
with the help of potencies proportionate to them.38
The will as an accident, like other potencies, is ordered to
the substantial subject; therefore, its acts are accomplished for
the sake of the subject. And it is through the will that selfdetermination of the person takes place, which, according to
Wojtyła, is the essence of freedom.39 This is what he explicitly
states in his later text based on Person and Act:
Self-determination of the person is accomplished through acts of will as the
central power of the human soul. . . . Self-determination is a property of the

36

Ibid., 86.
Ibid., 100.
38
Specific action is accomplished by a specific power, but it is not the power that is
the ultimate subject, as it does not have an independent existence. According to both
Aquinas and Wojtyła, an action cannot be understood in isolation from the subject. The
act of seeing can only be explained to some extent by the action of the eye as an organ
and by the very power of sight that uses it. It is at most an explanation of the way of
seeing but not of its cause. Ultimately, a given power, as an accident, finds its
explanation in the substance in which it exists. The subject uses this power to
accomplish a specific action.
39
The study of the person and his act covers many categories that are necessary to
discuss relationships between them, including self-determination, self-possession, selfcontrol, the immanence of the person in an act, horizontal and vertical transcendence,
morality, value, and freedom. It is not necessary, nor is it possible, to present them here.
37

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person defined by the well-known sentence “rationalis naturae individua
substantia,” while this property realizes itself through the will which is
power—an accident. Self-determination is the essence of human freedom. It is
not restricted in man only to the dimension of accidents, but belongs to the
substantial dimension of the person: it is the freedom of man and not only the
freedom of the will in man—although undoubtedly it is the freedom of man
through the will.40

This quotation demonstrates that Wojtyła is very keen to ensure
that the actions of the will and acts of self-determination do not
become ontically independent, and that they should be understood primarily in relation to the personal subject as a whole.
Acting is an act of the person as a substantial subject and not as
his accidents, and it is subordinated to the realization of the
freedom of that subject which consists in self-determination.
Self-determination cannot take place outside an act of the will,
but only the person (not the will) can self-determine. Thus,
Wojtyła supports Aquinas’s concept according to which an
action, although mediated by accidents, is an act of the substantial subject and can be properly understood and explained
only in relation to it. At the same time, thanks to this relationship, “every action is an external manifestation of the person”41 and thus the manifestation of the way in which he exists.
V. The PROPER OPERATION OF A THING
DEPENDS ON ITS NATURE
In Wojtyła’s view, the relationship between existence and
acting can be analyzed from the existential or the essential
perspective. As was mentioned above, in the latter case the
relationship between the action and the acting subject appears
as the most important. This relationship is expressed by the
word sequitur, “which states that there is a specific coherence
between the action and the one who acts. This coherence
cannot be expressed or understood in any other way than
40
Karol Wojtyła, “Osobowa struktura samostanowienia [Personal Structure of SelfDetermination],” in Wojtyła, Osoba i czyn oraz inne studia antropologiczne, 426.
41
Wojtyła, The Acting Person, 114.

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through nature.”42 It is nature that constitutes the link between
the existing subject and his action. The nature of the subject is
expressed in the action, and the analysis of the action makes it
possible to define nature.
Nature . . . is the basis of the essential cohesion of one who acts (though the
acting agent need not be human) with his acting. To put in a more generally
and more precisely, we may say nature provides the basis for the essential
cohesion of the subject of dynamism with all the dynamism of the subject.43

Wojtyła does not explain why nature mediates between a
subject and his action. Instead, he emphasizes that he is concerned with approaching nature as the source of all human
action that is understood as “humanity.” In his opinion, nature
is the “basic property of the acting subject” and, following the
Thomistic approach, it is identified with a dynamically understood humanity, which is treated as the source of the whole
dynamism of this subject.44 Nature determines the specificity of
human action, thereby allowing it to be distinguished from the
action of other beings. It permeates or rather expresses itself in
the whole dynamism of man, making it the dynamism of man
and not the dynamism of something else. It therefore encompasses both what is happening in the subject and the act in
which the subjective agency is expressed and through which the
subject self-determines.
The statement that man acts “through his nature” may give
rise to the suspicion that nature is understood here mechanistically, as a tool. For Wojtyła, man’s nature is “humanity,”
which is what gives man’s action the character of human action.
It is not something added to man, but the very essence of man
who expresses himself in action. And since man cannot act as a
42
Wojtyła, Osoba i czyn [Person and Act], 131. Cf. ibid., 83: “The statement that the
action is subsequent or follows existence it meant to indicate a specific cohesion of the
acting process and the acting agent. This cohesion is impossible to express otherwise
than by resorting to the conception of nature.”
43
Wojtyła, The Acting Person, 83.
44
See ibid., 82.

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human except within what he is (his essence), his actions are in
some way defined by nature.
However, this should not be understood as a limitation of
the person. Human nature is the proper way of manifesting
what the person is by virtue of his existential status. Wojtyła
explicitly states that humanity “permits” the concrete person to
exist and act as a person; at the same time, it “does not permit”
him to exist and act in ways other than as a person.45 What
nature “permits” and what it “does not permit” is not, however,
a coercion that is imposed from without or from within. It is
rather that which enables the person to be himself because it is
not only human nature but also the “person himself who is
human—that is ‘of man’.”46
Following Aquinas, Wojtyła emphasizes a particular relationship of the person to his nature. On the one hand, the human
person, as a human being, possesses certain characteristics and
acts in certain ways. Thanks to this, his nature reflects what is
common to all persons by virtue of their belonging to the
human species. On the other hand, this nature enables the
person to perform acts thanks to which he constitutes himself as
an autonomous subject of action. Thus, the rational nature of
man reflects both what is general and proper to all men (as a
species) and of what is individual and unique to him as a
person. As a result,
The person as such possesses, however, its own ontological structure, though
one very different from others that surround the human being in the visible
world. This difference, the proportion or rather disproportion that is
indicated in the words “somebody” and “something,” reaches to the very
roots of the being that is the subject.47

It is precisely this conceptual distinction between “someone”
and “something” that, according to Wojtyła, reflects a deep intuition of the human species’ distinctiveness and uniqueness.
Human action, due to its rational nature, is the action of
45

Wojtyła, Osoba i czyn [Person and Act], 132.
Ibid., 133.
47
Wojtyła, The Acting Person, 74.
46

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someone, not something, and at the same time the person
(someone) cannot act as a nonperson, that is, as something.
VI. THE CONTEMPORARY RESPONSE
Wojtyła was aware that his study would be discussed mainly
among Christian philosophers of the late 1960s in Poland, the
majority of whom were Thomists. Therefore, he referred to the
metaphysics and anthropology of Aquinas with particular care.
Nevertheless, his work met with some reservations and even
criticism.48 This criticism could primarily have been associated
with the novelty of his approach to the problem of man, in
which he tried to complement classical anthropology with
analyses of the first-person experience obtained through the
application of the phenomenological method.49 However, this
criticism was moderate and focused on his departure from the
Thomistic doctrine and on limiting his considerations only to
ethics. The omission of aspects of human existence other than
morality seemed to justify the rejection of the resulting anthropology. According to some authors, even if an act allows us to
say something about the person, it is insufficient to build all
anthropology on that basis.
Wojtyła did not intend to create a new anthropology that
would replace the classical approach to man. Instead, using the
tools provided by phenomenology, he wanted to deepen and
broaden the classical understanding of human beings by adding
to it an experiential aspect that was related to the first-person
perspective. The analysis of an act was not intended to eliminate
or replace analyses of other aspects of human existence or
action. Instead, he believed that the study of the act, in
48
The results of the discussion of several philosophers that took place at that time
can be found in Analecta Cracoviensia 5 (1973).
49
According to Rocco Buttiglione, in Wojtyła’s study Thomistic anthropology plays
the role of a “great fundamental hypothesis,” which, at the same time, guides and is
verified by phenomenological analyses: Rocco Buttiglione, “Kilka uwag o sposobie
czytania Osoby i czynu [A Few Remarks on How to read Person and Act],” in Wojtyła,
Osoba i czyn oraz inne studia antropologiczne, 15.

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PIOTR STANISŁAW MAZUR

accordance with the OSE principle, allows one to grasp the
specificity of human nature and the person as its subject. Therefore, his work goes beyond ethics and is of an anthropological
nature.
In the discussion that took place in Wojtyła’s intellectual
milieu after the publication of Person and Act, the issue of
anchoring his study in the OSE principle played a marginal role.
It is indirectly mentioned by Krąpiec and Jaworski, among
others, and only Styczeń refers to it directly. Interestingly, this
problem is not addressed by Kamiński,50 who investigates
methodological issues. Perhaps they treat the relation between
the person and his act as something obvious that does not
require special attention. As a result, the main principle of
Wojtyła’s analyses, although noticed, has not been critically
evaluated. Krąpiec states, for example, that the solution proposed by Wojtyła “can generally be reduced to the main claim:
through the analysis of a human act to affirm the person as the
subject of that act.”51 According to Jaworski, Wojtyła “undertakes an analysis of an act because, in his opinion, an act reveals
the person.”52 Similarly, Styczeń claims that the person expresses himself and objectivizes himself in an act, so analysis of
an act makes it possible to know the person indirectly as its
subject and agent.
As noted, of the numerous thinkers who have discussed
Wojtyła’s concept, only Styczeń directly refers to the Scholastic
OSE principle. In his opinion, Wojtyła’s claim that the person is
revealed through an act is one of many possibilities. An insight
into the person may also be obtained through experiencing the
duty of action or inaction, responsibility, moral good and evil,
love, interpersonal encounter and participation, astonishment,
50
See Stanisław Kamiński, “Jak filozofować o człowieku? [How to Philosophize
about Man],” Analecta Cracoviensia 5 (1973): 73-79.
51
Mieczysław A. Krąpiec, “Książka kardynała Karola Wojtyły monografią osoby jako
podmiotu moralności [Cardinal Karol Wojtyła’s Book: A Monograph of the Person as a
Subject of Morality],” Analecta Cracoviensia 5 (1973): 57.
52
Marian Jaworski, “Koncepcja antropologii filozoficznej w ujęciu Kardynała Karola
Wojtyły [The Concept of Philosophical Anthropology in Cardinal Karol Wojtyła’s
Thought],” Analecta Cracoviensia 5 (1973): 93.

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questions, a quest for the truth, or so-called “borderline
situations” such as “existential dread” or “being-towardsdeath.” However, only an act enables man to discover his own
essence, “revealing and explaining” him “in his entirety.” At the
same time, the objectivity (“objective reality”) and indisputability of an act that makes it impossible to interpret it in any
other way makes an act superior to other “anthropo-relevant”
facts.
Consideration of the intersubjective significance of the result is reflected here
in the preference for the most easily noticed, “publicly” accessible and
controllable starting point. We are supposed to know ourselves by our fruits
and in our fruits, according to the classical adagium “Agere sequitur esse.”53

Styczeń concentrates on the content of Wojtyła’s considerations,
presenting and supporting his idea of the person being revealed
through his act. However, although he notices the relationship
between the person and an act and the OSE principle, even he
does not realize to what extent Wojtyła’s concept is anchored in
Aquinas’s interpretation of this principle and how thoroughly
he must have thought it over before he used it in Person and
Act.
CONCLUSION
If Wojtyła had not taken the OSE principle into account, his
analysis would have been limited to a human act or human
freedom. His contribution lies in the fact that that he did not
limit himself to repeating the Scholastic principle but used all
the cognitive potential in this classical principle. Following
Aquinas, he interpreted it in a way that demonstrates the relationship between the act and the person as its subject.
Wojtyła’s analyses do not show the gradual process of
transition from the act to its subject—and thus from agere to
53

Tadeusz Styczeń, “Metoda antropologii filozoficznej w “Osobie i czynie”
kardynała Karola Wojtyły [The Method of Philosophical Anthropology in Person and
Act by Cardinal Karol Wojtyła],” Analecta Cracoviensia 5 (1973): 111.

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PIOTR STANISŁAW MAZUR

esse—that takes place in human cognition. Largely, together
with the understanding of agere/operari and esse, he assumes
this transition in the way proposed by Aquinas, and demonstrates various aspects of this relationship, often directly referring to the ready-made solutions offered by the medieval
philosopher. Aquinas’s concept constitutes a point of reference
for the analyses conducted by Wojtyła, and it serves as a means
of verifying their truth. At the same time, thanks to these
analyses, this relationship gains a contemporary interpretation
and is exemplified by descriptions from the perspective of the
first-person experience.
The validity of the OSE principle should not be limited to
the relationship between the person and his act. According to
Wojtyła, every manifestation of the dynamism of a being is a
manifestation of some aspect of his existence. Therefore, he
consistently uses this principle in his study to analyze concrete
activities of the person, such as consciousness, efficacy, transcendence, integration, and participation. These analyses allow
him gradually to penetrate more and more fully into the
structure of being and increasingly reveal what/who the person
is. The OSE principle thus plays the role of a presupposition
and the starting point in Person and Act, but it also permeates,
more or less explicitly, all of Wojtyła’s anthropological analyses.
The originality of his approach, however, does not consist in
the fact that in his analyses of man he refers to the dependence
between the order of existence and the order of action. This
was already done by Aristotle, Aquinas, and the representatives
of realist philosophy who identified the faculties of the soul on
the basis of its acts. Wojtyła, however, noticed a possibility to
use the dependence between existence and action, which is
contained in the OSE principle, to understand more fully the
relationship between the act and the person, and also to present
the person through his act.
Wojtyła’s work reveals that he thoroughly thought over what
it means that action follows being. In this way, he demonstrated
that the analysis of an act can be used to demonstrate the
uniqueness of the person as the subject of an act; also, he
demonstrated the uniqueness of an act as a manifestation of the

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dynamism of the person, thus completing the classic concept of
the human being. In doing so, he demonstrated the anthropological significance of the OSE principle itself.

BOOK REVIEWS
Deification through the Cross: An Eastern Christian Theology of Salvation. By
KHALED ANATOLIOS. Grand Rapids, Mich.: Eerdmans, 2020. Pp. 464.
$50.00 (hard). ISBN: 978-0-8028-7798-7.
Deification through the Cross is a hugely ambitious and impressive work.
Khaled Anatolios attempts to provide an account of Christian salvation—
grounded in Scripture, conciliar tradition, and liturgy—that responds to the
soteriological malaise of our times and that moves beyond a deficient “models”
approach. He entitles his approach “doxological contrition,” a neologism meant
to capture the core meaning of salvation. By “contrition” he means “repentance” (95); by “doxological” he means an account of salvation ordered to the
glory of God that reaches its culmination through the insertion of human beings
into the Trinity’s own mutual glorification: “True worship and the glorification
of the living God must be considered to be the ultimate goal and realization of
salvation” (90).
What precisely does Anatolios mean by “doxological contrition”? He answers this question through a series of summaries throughout the book that
restate the primary thesis. “I speak of Christ’s ‘doxological contrition’ as
effecting our salvation and of our salvation as a conscious participation in
Christ’s doxological contrition” (xiv). This account of salvation, then, includes
both what Christ has done for us and how we are enfolded into salvation
through participating in what Christ has done for us: “Christ saves us by rendering perfect glory to the Father in the Spirit and by enabling us to glorify the
Triune God with him and in him, and . . . he also saves us by being perfectly
contrite in expiation of human sinfulness and thus enabling us to repent with
him and in him” (88).
Before setting out to demonstrate this thesis, Anatolios calls our attention to
two specific “backdrops” that orient his study. The first consists of impediments
found in our modern context that inhibit Christians from realizing the full joy
of their salvation. By pointing to “the eclipse of atonement” he identifies a
general rejection of the principle of atonement in both scholarly and popular
circles that “leads to a breakdown of the intelligibility of the Christian teaching
about salvation in general” (3). He then takes sharp aim at the contemporary
habit of speaking about salvation in terms of discrete models. Though he does
not want to deny the presence of these models in Scripture and the Fathers, he
argues that stacking up models is not a helpful strategy for understanding
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salvation: “The task of a theology of Christian salvation cannot be exhausted
by piling up one model after another. The theologian must generate normative
statements that are in principle applicable to any candidate for a Christian
‘model’ of salvation” (23). Finally, Anatolios points to “the lack of experiential
access to this doctrine (of salvation)” in the liturgical worship of the Church
(ibid.). He believes that an account of salvation as “doxological contrition” can
reinvigorate a plausible notion of atonement, undergird the various “models”
in a doctrinally grounded foundation, and open the way for a joyful experience
of salvation through conscious participation in Christ’s saving death and
resurrection in the liturgy.
The second “backdrop” against which Anatolios offers his thesis is what he
calls “the contrived modern binary between the putatively ‘ethical’ Western
approach to sin and salvation and the supposedly ‘ontological’ Eastern
approach” (47). He believes this binary “has not only alienated Eastern and
Western traditions from each other but also alienated Eastern Christians from
the fundamental sources of their own tradition” (ibid.). By calling witnesses
from both the Eastern and Western theological traditions in support of his
project, Anatolios effectively reintegrates the ontological and ethical aspects of
sin and salvation, and so offers an account that reflects an approach found in
both the East and the West.
Deification through the Cross is divided into two parts. In the first, Anatolios
investigates foundational sources for a soteriology of doxological contrition:
Scripture, conciliar (dogmatic) tradition, and the (Byzantine) liturgy. In the
second, he pursues his thesis in a more systematic way by considering the core
topics (sin, salvation, intra-Trinitarian glorification) through the writings of key
interpreters drawn from both East and West. The density and richness of this
theological investigation makes it impossible to give an adequate summary.
Instead, I will follow the main outline of the investigation and offer representative comments and summaries along the way.
Though Scripture is listed as the first and foundational source, Anatolios
begins his investigation by examining the witness of the Byzantine liturgy: “The
impetus and ultimate orientation of this work is therefore the liturgical
experience of the Byzantine Christian tradition” (36). Tracking the liturgical
prayers from the season of Lent through Easter and up to Pentecost, Anatolios
discovers a clear witness to both “doxological contrition” and to a predominant
concern for sin and repentance. Repentance, however, is not a human work that
merits salvation but a gift of grace, opened up by Christ’s own representative
repentance on our behalf by which we receive the gift of salvation: “The
worshiper is given no opportunity to offer repentance as a human work that
merits ‘grace’; repentance itself is the gift, the grace, to be asked for” (76). The
foundational dynamic of the Byzantine liturgy, then, is its dramatic synthesis of
the dialectic of sorrow over sins and the celebration of divine glory. “It is
precisely this experiential synthesis that we are designating ‘doxological
contrition’” (81).

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Anatolios next explores three scriptural “moments” that illustrate
“doxological contrition”: the deliverance of Israel from Egypt, the return of
Israel from exile in Babylon, and the advent of Jesus the servant of the Lord.
For Anatolios, the point of the servant’s suffering is not the suffering itself
(bearing God’s wrath) but a representative suffering in the mode of repentance
that leads to reconciliation: “One of the key components of the soteriology of
doxological contrition that we are in the process of constructing is that it
replaces the notion of the salvific efficacy of punishment with that of the salvific
efficacy of contrition” (139). The narrative of Jesus’ baptism, especially in
Matthew, unites these features of representative repentance and the manifestation of divine glory: “The fact that this manifestation of trinitarian glory
coincides with Jesus’s repentance on behalf of sinners should lead us to conclude
that it is precisely through his representative repentance on behalf of sinful
humanity that Jesus forges a path of ‘return’ to the heart of trinitarian glory”
(156).
When treating “doxological contrition” in conciliar doctrine, Anatolios leads
us on a learned tour through the soteriological doctrine of the first seven ecumenical councils. His overall conclusion is that Trinitarian and Christological
doctrine is the foundation for soteriology; he calls this the “soteriological
grammar inscribed into the church’s normative trinitarian and christological
doctrine” (223). From this, he concludes that “salvation thus essentially consists
in graced incorporation into Christ’s humanity, which brings about assimilation
to Christ’s divinity and inclusion into trinitarian life from the position of the
Son’s relation to the Father and the Spirit” (168). He describes this as a
“particular inflection of the doctrine of deification . . . which thus understands
human deification as inclusion into the divine self-glorification” (226).
In the systematic section of the study, Anatolios seeks to confirm his initial
findings from the sources by the study of core topics (sin, salvation, intraTrinitarian glorification) through recourse to key interpreters. These include
Irenaeus, Anselm, Thomas Aquinas, Gregory Palamas, and Dumitru Staniloae,
but Anatolios’s two primary witnesses to “doxological contrition” are Matthias
Scheeben (from the West) and Nicholas Cabasilas (from the East). Some of the
most constructive and fertile insights of the study appear in these chapters, in
which Anatolios attempts to integrate a deep understanding of human sin with
the doxological vocation to glorify God. “The essential core of the gospel, from
the perspective of a soteriology of doxological contrition, is that God marvelously accomplishes both his doxological judgment against sin and humanity’s
full reintegration into the intra-trinitarian glorification, through Christ’s
representative and inclusive doxological repentance” (312). All this happens
through the Cross—and thus, the aptness of the title of the book, Deification
through the Cross.
Not content to elucidate a positive account of doxological contrition,
Anatolios concludes his study by engaging in a dialogue of comparison with
three contemporary accounts of Christian salvation: liberation theology (in the
writings of Jon Sobrino), the mimetic theory of René Girard, and the doctrine

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of penal substitution. Anatolios appreciates the insights of the first two accounts, especially in their identification of real human sin and suffering in
concrete human experience, but he finds them deficient in their reduction of
Christian salvation to matters of human justice or to the eradication of human
violence, and contends for the view that salvation is “ultimately the enablement
of humanity to offer perfect worship to the living God” (408). When treating
penal substitution, Anatolios rightly upholds the biblical basic for this doctrine
but, in my view, brilliantly modifies the traditional account by putting the emphasis not on the sheer assumption of punishment and the exhausting of divine
wrath, but on the Son bearing our punishment representatively and contritely
while in full possession of the vision of the glory of the Father (420).
If there is one point I would critique in the project of “doxological contrition,” it would be Anatolios’s tendency at several points to minimize and set
to one side the “Christus Victor” aspect of Christ’s work of salvation. Anatolios
justifiably finds Gustav Aulén’s “Christus Victor” model unsatisfactory (11-14),
but this seems to color his reading of the victory motif wherever he finds it. In
all of the main sources he cites—the Byzantine liturgy, Scripture, and the
councils and theologians of the Christian tradition—this aspect of Christ’s
victory over hostile powers appears prominently. Anatolios rightly concludes
that God’s interaction with the human race (Christ’s doxological contrition) is
the core element in the Christian narrative of salvation, with victory over the
devil playing a secondary role (196). But there seems to be a curious reluctance
to give this victorious aspect of Christ’s work an active place, even though all
his sources do so. Anatolios admits, for example, that Cabasilas, his primary
witness to doxological contrition, “trades heavily in ‘Christus Victor’ language,”
but then sets this aside by claiming that the logic of Cabasilas’s theology
“provides a demythologization of that imagery” (367). This is unpersuasive. In
the text cited (364), Cabasilas speaks of the baptized reproaching the tyrant,
spitting upon him, and turning his back on him, while praising the champion
(Christ) and loving him with his whole soul. This is not demythologization of
the victor motif but a full-blooded and literal grasp of the real victory over
hostile powers that Christ wins. Christ’s statement on the “binding the strong
man” (Matt 12:28-29) and John’s assertion that “the reason the Son of God
appeared was to destroy the works of the devil” (1 John 3:8) is not mythology
but reality. To acknowledge and integrate the victory motif within a soteriology
of “doxological contrition” would not mean simply adding another “model” on
top of the foundation, but displaying how—in all the main sources—Christ’s
doxological repentance includes victory over the hostile powers that enslave the
human race.
Anatolios recognizes that in Deification through the Cross his “goal is to say
something about Christian salvation that has not been said before, at least not
in the exact terms being now proposed” (169). He admits “the seeming novelty
of its explicit formulation” but argues that it is capable of a broad assimilative
and synthetic power in relation to the whole Christian tradition, East and West
(375). In one instance he speaks about his effort of “constructing” a soteriology

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of doxological contrition (139), but it seems to me that the thesis is something
more like a “discovery,” a treasure found embedded in the prayers of the Byzantine liturgy, that is then worked out (“constructed”) by a close examination of
the sources (Scripture and tradition). Anatolios acknowledges that there is much
work yet to be done to test and expand his thesis, but he has made an impressive
beginning by persuasively demonstrating—in Scripture, tradition, and liturgy—
how “doxological contrition” illuminates and expresses the Christian doctrine
of salvation.
DANIEL A. KEATING
Sacred Heart Major Seminary
Detroit, Michigan

Reading Job with St. Thomas Aquinas. Edited by MATTHEW LEVERING, PIOTR
ROSZAK, and JÖRGEN VIJGEN. Washington, D.C.: The Catholic
University of America Press, 2020. Pp. 416. $65.00 (hard). ISBN 9780-8132-3283-6.
With the exception of a 1997 monograph by Denis Chardonnens (L’homme
sous le regard de la providence: Providence de Dieu et condition humaine selon
l’“Exposition littérale sur le Livre de Job” de Thomas d’Aquin), the present
volume is the only book-length study of Thomas Aquinas’s commentary on the
Book of Job. Given the historical significance of the commentary, this is surprising. Aquinas was, after all, the first Christian interpreter to treat the literal
sense of the Book of Job. The full title of the commentary, Expositio super Iob
ad litteram, signaled a new approach. Acknowledging the stature of Gregory’s
Moralia in Job in the prologue to his own commentary, Aquinas intended to
steer clear of the spiritual or mystical sense, which had already been explained
“both accurately and eloquently by the blessed Pope Gregory.” Aquinas’s
interest lay instead with the capacity of the literal sense of Job to convey
probable arguments for a divine providence that governs human affairs. Perhaps
because Aquinas’s views on providence are presented in a more orderly fashion
in his systematic works, scholars interested in this topic have, until now, paid
comparatively less attention to the ways in which the literal sense of a scriptural
story like Job’s afforded Aquinas new and interesting opportunities to expound
on the topic of providence—and, indeed, a good deal more.
Reading Job with St. Thomas Aquinas contains thirteen incisive essays from
established scholars on the backgrounds and themes of the Expositio. These are
divided into three parts: “Job and sacra doctrina” (chaps. 1-3), “Providence and
Suffering” (chaps. 4-9), and “The Moral Life and Eschatology” (chaps. 10-13).
The volume begins with a brief introductory essay in which the editors provide

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useful background for the composition of the Expositio, along with short discussions of Aquinas’s exegetical practice and his understanding of Job as a man
who believed in the resurrection (by way of revelation rather than reason) but
erred in scandalizing his friends when provoked to defend his innocence. No
doubt because this point is essential to Aquinas’s understanding of the book,
nearly all the contributors revisit or reinforce this portrait of Job in their essays.
The contributors also echo one other in pointing out additional features of the
Expositio: (1) that Aquinas was likely writing about providence for book 3 of
the Summa contra gentiles at the same time that he was writing the Expositio;
(2) that the commentary format prevented Aquinas from writing on topics in a
systematic way; (3) that Aquinas viewed the book as a disputatio, with Job and
the friends on opposing sides and God as the final arbiter; (4) that an
Aristotelian rather than Stoic understanding of emotion helped Aquinas to
understand the vehemence of Job’s feelings sympathetically; and (5) that Job
spoke in three ways, according to passion, reason, and revelation.
The first three chapters examine Aquinas as teacher, philosopher, and
biblical interpreter. John Boyle (chap. 1) argues that Aquinas’s experience of
disputations in Paris disposed him to see the Book of Job in similar terms: as a
debate among learned men on theological matters. At stake in the book and in
university disputations is the attainment of wisdom, a grasp of reality in terms
of highest causes. Importantly, disputations reveal character as well as intellect,
and Aquinas sees in Job a man who attains a fuller measure of wisdom by virtue
of a humble response to correction by the divine Master. One would expect
Aristotle to bulk large in Aquinas’s philosophical or systematic works, but
Jörgen Vijgen (chap. 2) demonstrates that the influence of the Philosopher is
clear and strong even in a biblical commentary like the Expositio. Perhaps more
surprising is Vijgen’s claim that, in addition to helping Aquinas with questions
about virtue, emotion, and natural philosophy, Aristotle’s thought was essential
to his arguments concerning providence and the prospect of bodily resurrection,
thus yielding an exemplary “integration of faith and reason” (67). Because the
New Testament authors relied on the writings of the Old Testament, scholars
readily affirm that the latter are indispensable to understanding the former. But
can the New Testament illuminate the literal sense of the Old Testament? In a
careful review of places where Aquinas cites the Gospel of John in the Expositio,
Matthew Levering (chap. 3) demonstrates that, for Aquinas, it can and should.
Job’s words and experiences are intelligible in a world where the hope of the
pious rests on an incarnate God who overcomes darkness and calls the dead
back to life. It was fitting for Aquinas to turn to John’s Gospel, because he
understood Job to inhabit the same world into which Christ brought longpromised light and to serve the same God who was himself “the resurrection
and the life” (John 11:25).
The next chapters turn to the nexus of wisdom, suffering, and providence in
the Expositio. Divine inscrutability is a prominent theme in the Book of Job. In
an exceptionally clear and penetrating essay, Serge-Thomas Bonino (chap. 4)
explains how Aquinas framed and analyzed this theme—not in terms of an

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arbitrary or irrational divine will, but rather as the exalted wisdom of the
Creator. When it comes to this wisdom, humans are able to participate in it, but
never in a way that fully comprehends the wisdom of God in se. According to
Bonino, Aquinas saw himself in the figure of Job, a man searching out divine
matters, even desiring to debate with God, yet always with humility and in
connection with personal sanctification. Looking at the Expositio along with
book 3 of the Summa contra gentiles, Rudi Te Velde (chap. 5) notes that Aquinas’s systematic treatment of providence informed his interpretation of Job.
Surprisingly, though, Job does not appear in the Summa contra gentiles. Job is
rather a special case of a man who recovers faith in moral order at the
extremities of personal suffering. Providence orders all things for the good, but
an essential difference in the outworkings of providence for nonrational creatures (useful to higher ends) and for rational creatures (ends in themselves) must
be acknowledged. Job’s sufferings have to do with God’s providential care for
him as a rational being, who will live on after death. For those perplexed by the
so-called “whirlwind speeches” (Job 38-41), Guy Mansini’s essay (chap. 6) is a
must-read. The sufferings of Job make his virtue apparent to others and, in so
doing, correct mistaken understandings of providence such as Job’s friends
have. Yet this is not all that they do. With the appearance of God at the end of
Job’s trial, Mansini argues that “Job’s virtue, revealed by trial, also reveals the
one for whom all else is to be despised. . . . The manifestation of God and the
manifestation of Job’s virtue constitute a single reality” (151). In addressing Job,
God “shows up” for Job, to settle questions of truth, to demonstrate his mastery
over the devil (figured in Behemoth and Leviathan), and to console Job as a
friend. In turning a permitted evil into a great good that subverts evil itself, the
Book of Job is ultimately cruciform.
The topic of sin is central both to the Book of Job and to the Expositio. Harm
Goris (chap. 7) observes that Aquinas’s treatment of sin in the commentary lacks
the precision, detail, and order evident in accounts of sin found in his systematic
works. Yet Goris sees value in the opportunity afforded to Aquinas to discuss
sin in a “more concrete, holistic, and realistic” way as it manifests “in the
ordinary lives of people” (183). Aquinas analyzes Job’s claim to innocence, the
kinds and causes of sin, as well as the relation of sin and suffering, thus
illuminating the experience of the faithful in an unusually vivid way. In a rich
and suggestive essay, John Knasas (chap. 8) examines the purpose of human
suffering and the question of human destiny from the perspective of the
“Thomistic philosopher,” someone who espouses philosophical positions
informed by Christian truths but who is not yet Christian. Knasas argues that
the Thomistic philosopher espies the possibility of Christian truths but does not
arrive at them. The distinction between what is available to humans by reason
and by faith is crucial. Job’s friends reasoned wrongly in arguing that this life is
the only life, and Job, for his part, erred by speaking of a theological truth
(resurrection) as though it could be demonstrated philosophically. Joseph
Wawyrkow (chap. 9) undertakes a helpful comparison of Aquinas’s treatments
of merit in the Summa theologiae and in the Expositio. According to Wawry-

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kow, the two are broadly similar. By consulting Aquinas’s systematic discussion,
one comes to understand his affirmation and understanding of merit, usefully,
in terms of wisdom rather than justice. In wisdom, God ordains it so that
humans are rewarded for perseverance and good work; God is not compelled
by justice to bestow merit. Job’s adversity and subsequent restoration show that
God wisely “distributes temporal goods, and evils, in accordance with God’s
providential plan” (258). What happens in this world is conducive to individuals’ journeys to salvation; reward and punishment take place, as Job knew,
in the next life.
Part 3 of the book turns to moral philosophy and eschatology. According to
Daria Spezzano (chap. 10), Aquinas does not present Job as a static example of
faith and virtue but rather as a dynamic one, a man who experiences “transformation” over the course of the book (311). Not only does he move through
stages in his manner of speaking (passionate, rational, inspired); Job is perfected, specifically, by an increasingly “perfect realization of his hope” (265)
and a fear of God that causes him to cling to God as a servus amoris. In arguing
with Job, the friends cause him to express his faith in the resurrection and in
God’s goodness yet more clearly. In this, Job is a model of how to respond to
suffering. One feature of Aquinas’s concentration upon the literal sense is
careful attention to moral themes. Examining three in particular—the morality
of the passions, cognizance of humanity’s ultimate end, and Job’s “scandalous”
assignment of justice to the afterlife—Brian Mullady (chap. 11) offers an
exceptionally clear guide to the moral terrain of the Book of Job as Aquinas saw
it, a terrain that one navigates successfully only in light of divine providence
and a theological affirmation of divine judgment in the world to come.
Following a pattern evident elsewhere in the volume, Anthony Flood (chap. 12)
examines Aquinas’s position on a particular topic and then discusses its reflexes
in the Expositio. Taking “friendship” as his topic, Flood notes that the “most
complete kind of union” is friendship, and thus “friendship with God provides
the greatest realization of the greatest union for which human beings can hope”
(341). This is, for Aquinas, a metaphysical reality that finds dramatic expression
in the Book of Job. Both human friendship and friendship with God emerge as
key themes in the life and trials of Job. It is fitting that the chapter devoted to
eschatology comes at the end of the volume. Though the Book of Job does not
address the eschaton in an explicit way, Bryan Kromholtz (chap. 13) argues that
Aquinas, in reading this part of Scripture according to the analogia fidei,
ultimately makes sense of the book by drawing on theological truths concerning
resurrection and the afterlife. The book itself points in their direction, as when
Job is not given twice as many children at the end of the book. He is blessed
with the same number as before. Yet his children are in fact doubled, because
he will receive his first family back again in the resurrection (379).
Kromholtz closes his essay (and, as it happens, the volume as a whole) with
a statement about Aquinas’s theological reading of the Book of Job: “We might
say that the reason the book of Job makes more sense in light of the faith,
including the promise of a glorious resurrection for the just, is that life makes

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more sense in that light” (383). To those who regularly keep company with
Aquinas, this statement will perhaps seem like a useful summary of a familiar
and sensible theological maneuver: namely, to make sense of the Old Testament
(and Job in particular) in the light of the resurrection and a Christian understanding of reality. As an outsider both to systematic theology and Thomistic
studies, however, I see Aquinas’s comprehensive interpretation of a book as
jagged, difficult, and subjective as Job as an extraordinary feat—one which
raises a question. Neither the editors nor the contributors should be blamed for
their placid, reassuring, and well-reasoned expositions of the Expositio, still less
for Aquinas’s own crystalline exegesis of a famously obscure biblical book. In
this volume, the contributors work as Aquinas did, with conviction about the
ultimate concord of faith and reason, theology and philosophy, exegesis and
dogma, grace and nature. But can concord ever become complacent or
misleading?
One example of supposed concord concerns biblical studies and theology. In
the introduction, the editors sound false notes about supposed similarities
between Aquinas and modern academic interpreters of Job. Both, they say, are
interested in providence (3). They also connect the Expositio to the sub-field of
reception history, because both credit the importance of earlier interpretation
for understanding the Bible (12-13). Noting these commonalities is like saying
that Diogenes the Cynic and King Midas both had thoughts about gold. To a
great degree, modern biblical scholars see (a) Job as an example of an audacious
heterodoxy, (b) the God of Job as arbitrary and tyrannical, and (c) the Book of
Job as a needed dissent to a stifling, purblind tradition. Job, on this account, is
not a perfected servus amoris looking toward the afterlife but an unbowed,
clear-eyed rebel against the Almighty, as, for example, in Edward Greenstein’s
recent Job: A New Translation (Yale University Press, 2019). Greenstein’s
avowed purpose is to “set the record straight” by restoring the image of a defiant
Job, but, in fact, his work is not so much a correction of a “record” as a recent
entry in the old historical-critical quest for a free-thinking Job unspoiled by later
pieties. For modern scholars working in this vein, Aquinas’s Job is the exegetical
enemy to be vanquished. And even for many modern people who are not part
of this “quest,” a Job who is willing to question providence and reject pat
answers has been a bulwark against what are seen as facile theologies.
What of concord within the book of Job itself? I believe that the modern
critical portrait of a recalcitrant, heterodox Job is limited and misleading, but it
nevertheless takes seriously aspects of the Book of Job that contemporary
theologians ought to address: for example, the painful and radical dislocation
of Job as a servant of God who is given over to Satan and various instruments
of death. It is a harrowing tale about a real man who, as Aquinas said, existed
in rerum natura. In the introduction to Reading Job, the editors explain that it
is appropriate to take Job’s “existential agony” more literally than Aquinas does
(11-12), but the essays, for the most part, treat Job’s suffering abstractly. On
the whole, critical biblical scholarship is hostile to theological categories, but
critical analysis can be useful in disciplining the drive toward abstraction.

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Perhaps sensing this, the editors affirm the value of historical-critical exegesis
in shedding light on Job’s particular situation, but they state that consulting this
exegesis “should not mean supplanting the theological insights of patristic and
medieval interpreters” (13). This word of counsel is not, in my view, a sufficient
acknowledgment of the challenges posed by modern interpretations of Job to
traditional Christian theology. It is also naïve. Of course historical-critical
readings “supplant” premodern ones. Doing so is and has been their raison
d’être, and the Book of Job is a parade example. It is better to face critical
scholarship’s agonized and audacious Job directly than to imagine that
scholarship’s putative “historical” orientation somehow makes it
complementary to (or sealed off from) theological readings.
Reading Job with St. Thomas Aquinas does precisely what the title says: the
volume explores what it meant for Aquinas to read the Book of Job. The
volume’s contributors explore this in ways that are illuminating and edifying—
but almost entirely with a view toward clarifying Aquinas’s hermeneutical
maneuvers for those already acquainted with his larger synthesis. This is a noble
and needed task, and the contributors in this volume carry it out exceptionally
well, but at some distance, it seems, from the tumults and whirlwinds that, for
good or for ill, have been and continue to be part of the Joban tradition.
MICHAEL C. LEGASPI
Philips Academy
Andover, Massachusetts

What It Means to Be Human: The Case for the Body in Public Bioethics. By O.
CARTER SNEAD. Cambridge, Mass.: Harvard University Press, 2020. Pp.
336. $39.95 (hardcover). ISBN 978-0-674-98772-2.
In What It Means to Be Human: The Case for the Body in Public Bioethics, a
leading Catholic thinker in the law of bioethics has laid bare the “expressive
individualist” anthropology structuring U.S. public bioethics, and proposed an
alternative that accounts for human embodiment. Previously serving as General
Counsel at the President’s Council on Bioethics, O. Carter Snead presently
directs the University of Notre Dame’s de Nicola Center for Ethics and Culture,
a leading source of scholarship and public dialogue about the Catholic moral
and intellectual tradition.
The book claims that current public bioethics law has an undeclared,
underlying anthropology that does not “reflect the full complexity of lived
reality” (1). It fails to acknowledge that human beings are “embodied,” which

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means that we are also vulnerable, dependent, and naturally limited. Instead, it
presumes that people are “atomized individual wills” whose flourishing is
constituted by “interrogating the interior depths of the self in order to express
and freely follow the original truths discovered therein toward one’s selfinvented destiny” (5). Laws, regulations, and public policy grounded in this
conviction thus fail to comprehend human needs or promote human
flourishing. They leave the weak alone with their state-recognized privacy and
autonomy. They ignore human beings’ obligations to vulnerable others. They
fail to promote genuine equality and freedom.
Snead subjects public bioethics to an anthropological inquiry to surface its
unspoken convictions about human identity and flourishing. He then proposes
a new anthropology, securely anchored in human beings’ embodied state, for
purposes of inspiring a new body of law attuned to humans’ true needs and
desires. And he applies these anthropological insights to craft principles and
policy goals applicable to abortion, assisted reproductive technologies (ARTs),
and end-of-life decisions.
Snead begins with a riveting and occasionally horrifying account of the
history of U.S. bioethics laws. It began in the 1960s with publications exposing
experiments upon unconsenting and vulnerable subjects, including Black males
with syphilis (the Tuskegee experiments), and still-living aborted infants. The
pattern for crafting bioethics laws is first set here: lawmakers react to past
abuses; some portion of the scientific community continues to justify them;
legislatures establish commissions to study the problem; and the law eventually
enshrines the principle of “informed consent” presumably given by able,
autonomous, rational human persons. This pattern shaped legal responses to
later controversies over fetal-tissue research, genetic manipulation, assisted
reproductive technologies, abortion, and end-of-life decision-making.
Interrogating these laws and policies, Snead determines that they reveal an
anthropology of “expressive individualism,” a term coined by Robert Bellah to
describe a belief that human identity and flourishing involves expressing one’s
“innermost identity through freely choosing and configuring life in accordance
with his or her own distinctive core intuitions, feelings and preferences” (69).
Such an anthropology is dualistic. Human cognition and will are paramount.
These use the body as an instrument for achieving personal projects according
to subjective values, not beholden to exterior “givens” or the needs of
vulnerable others.
Snead relies heavily upon the philosophical treatments of this anthropology
in the works of Alasdair MacIntyre, Michael Sandel, and Charles Taylor, and
applies their insights to public bioethics. He concludes that because this
anthropology forgets the body it cannot factor in weaknesses, dependencies,
and limits that characterize every human life. These include, at a minimum,
childhood, disability, age, illness, cognitive limits, and even human beings’ need
for cooperation and dispute in order to understand themselves. Thus it also fails
to foster laws and policies recognizing mutual social obligations and facilitating

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the building of networks of “giving and receiving that are essential to the
survival and success of all human beings” (184).
In response, Snead recommends a new anthropology to inform lawmaking
based upon humans’ need for “uncalculated giving and graceful receiving”
(quoting MacIntyre [7]). It would foster MacIntyre’s “virtues of acknowledged
dependence” (99), including just generosity, hospitality, misericordia, humility,
openness to the unbidden, solidarity, truthfulness, friendship, and a willingness
to look outward to the dignity and good of others.
Snead applies his analysis to U.S. law and policy on abortion, ARTs, and endof-life decisions. In each case, he thoroughly reviews existing laws and cases—
and in the case of ARTs, the notable absence of law, in deference to market
logic—describing with precision the ways in which each manifests expressive
individualism. He highlights the vulnerabilities that the law ignores concerning
each of the persons involved: the pregnant woman, the child, the egg donors,
the surrogates, the infertile would-be parents, the sick, the dying, the disabled,
the depressed, and the cognitively impaired.
With respect to each area of law, Snead recommends new law and policy—
neither liberal nor conservative—to enable a better, truer response to human
needs. Such law would promote networks of uncalculated giving and grateful
receiving. It would “encourage and reward” all of the virtues needed to enable
these. It would strengthen familial and social ties and cultivate individuals’
moral imaginations so that they might see others they owe, and from whom
they might demand, care: parents, extended family, boyfriends, doctors, and
others. Should these networks be absent or insufficient, government would play
a role.
Several times, Snead asserts that he is offering only “principles” and “policy
goals” (9) and that he is not proposing precise legal solutions for each contested
question. He does, however, make several bold proposals including the protection of unborn children from the moment of conception, close regulation or
even bans upon reproductive technologies endangering the health or well-being
of the children conceived, ensuring that every child created via ARTs has the
opportunity for a loving family environment (versus allowing freezing or destroying human embryos), and banning the direct hastening of or causing of
death.
Snead’s ideas are an important contribution to three areas of inquiry. First,
his book constitutes a critique of contemporary liberalism’s fixation on the
individual, to the exclusion of the numerous networks and institutions upon
which human beings must rely. In this way, it is in the tradition of Patrick
Deneen’s Why Liberalism Failed, Mark Lilla’s The Once and Future Liberal, and
Martha Fineman’s family-law scholarship concerning the “vulnerability thesis.”
Snead’s work brings this lens to bear, instead, on bioethics law, during a time in
which questions about transsexual surgeries, manufactured embryos, and
artificial intelligence will only heighten the perception of a bioethics emergency.
Second, this book thoroughly applies for the first time to the field of
bioethics a valuable method invigorated in recent decades by Pope John Paul II:

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querying the anthropology undergirding accounts of human identity and
flourishing human life. Contemporary accounts regularly insist that they have
no anthropology at all, no “comprehensive world view,” as that is characterized
by John Rawls in his A Theory of Justice. Instead, they claim merely to be
following the science, or allowing for maximum expression of individual will in
a pluralistic democracy designed to allow this type of freedom.
Other authors have exposed this fallacy: philosopher Michael Sandel in his
critique of Rawls, law professor Elizabeth Schiltz respecting certain strands of
feminism, and theologian David Schindler in his examination of contemporary
liberalism’s opinions about religious freedom. Snead performs this service—
peering behind the curtain of science and claimed democratic norms—to expose
the anthropology underlying contemporary bioethics laws.
Finally, Snead’s book offers a counterweight to the legal scholarship that, at
present, is doubling down on expressive individualism. The vulnerable persons,
limits, and dependencies Snead depicts are regularly invisible in this scholarship.
Unborn children, egg donors, and surrogate mothers are almost never
mentioned. When vulnerable parties are acknowledged, it is usually in order to
ground a demand for their right to terminate a pregnancy or end a suffering
life, or commodify reproduction, often with the assistance of the state.
Snead instead highlights human weaknesses as a predicate for asserting
human beings’ mutual social obligations, beginning especially within the family,
and moving to government only when necessary. Today, families are still
suspect as hotbeds of inequality, sexism, and constraining tradition. And family
members remain the only people one can kill with legal impunity, whether via
abortion, euthanasia, or ARTs that produce “excess” embryos. Snead’s book is
a valuable corrective to this body of literature, both because of his linking
vulnerability with the obligation to care, and because of his embrace of
subsidiarity.
The book is also valuable for several discrete contributions it makes. It
provides a brief but highly informative summary of the development of public
bioethics law in the United States. Readers can see in the story not only the
domination of individualist thinking, but also the powerful sway of the scientific
establishment. It is a cautionary tale. It would be hard to understand today’s
predicament if we did not understand the environment in which the die was
cast that shaped U.S. bioethics law according to expressive individualism.
Snead’s empirical and personal accounts of human vulnerabilities and
interdependencies in the context of abortion, ARTs, and end-of-life decisions
are also quite valuable. He provides valuable data regarding outcomes rarely
made visible to the public: risks to children conceived using ARTs, side effects
suffered by surrogates, and the states of mind and risk of abuse respecting sick
or elderly patients expressing a wish to die. Sometimes his accounts are even
moving, as in his account of the mother-child relationship (140). Both types of
evidence have real potential in courts of law and in courts of public opinion
The book provides several answers to the question of why the U.S. law has
embraced expressive individualism so fervently. Snead suggests American

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individualism, an obsession with sexual freedom, industry (ARTs and health
care generally), power, and a die that was cast at the dawn of our public
bioethics. He might also have included some discussion of the hardball political
might of interest groups, because the combined strength of these groups
alongside an increasingly powerful corporate sector is a powerful bulwark
against change, even when faced with arguments as true and appealing as
Snead’s. This will be true to an even greater degree regarding two issues this
book does not approach: artificial intelligence and surgery to alter sexual
appearance.
Americans clearly long for the kind of networks of mutual care Snead
depicts. Right and left would support many of his ideas, in theory. This is
apparent in Americans’ sympathetic reactions to groups fighting racial
discrimination and poverty today. But these groups do not have corporate and
political forces in addition to wealthy interest groups denouncing their demands
as fundamentally anti-freedom; groups fighting for justice regarding abortion,
ARTs, and end-of-life decisions do.
It is important to avoid the “fallacy of the present”—the idea that things will
always be as they are now. But it is also important to take the next step Snead
exhorts: crafting particular laws and policies to protect embodied persons, as
well as the arguments sufficient to overturn Americans’ intense affection for
expressive individualism. Additionally, proposed solutions have to consider that
many are content to leave solutions to human suffering to the government, to
receive only the “science” that suits their preconceived ideas, and to express
compassion for those far away, while avoiding the hard work of sacrificing for
those in our own families or communities. In the immortal words of Father
Zossima in Dostoyevsky’s The Brothers Karamazov: “Love in action is a harsh
and dreadful thing compared with love in dreams. Love in dreams is greedy for
immediate action, rapidly performed and in the sight of all. Men will even give
their lives if only the ordeal does not last long but is soon over, with all looking
on and applauding as though on the stage. But active love is labour and
fortitude.”
HELEN M. ALVARÉ
Antonin Scalia Law School, George Mason University
Arlington, Virginia

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Thomas Aquinas: A Historical, Theological, and Environmental Portrait. By
DONALD S. PRUDLO. New York: Paulist, 2020. Pp. 420. $39.95 (paper).
ISBN 978-0-8091-5386-2.
Donald Prudlo’s portrait of Tommaso d’Aquino (1224/6-74) offers a moving
account of the great saint and theologian, presenting him as a human being who
lived in particular historical, institutional, and geographic circumstances, who
had personal relationships with others, lived out of a recognizable spirituality,
and possessed a distinctive personality. That personality included natural
strengths and weaknesses, both of which fitted Thomas for his unique vocation,
mission, and striving for sanctity. Prudlo’s treatment of Thomas’s theology will
not satisfy serious students, but the book’s lively sketch of “the life and times of
this Dominican thinker” (5) and its sustained “meditation on the interrelationship between scholarship and sainthood” (ibid.) make it a valuable
companion and complement to the study of Thomas’s own writings.
The Introduction announces Prudlo’s aim to write a biography of Thomas
Aquinas that occupies a middle space between “popular (sometimes uncritically
hagiographic) and . . . exceptionally academic” biographies, such as those by
Simon Tugwell, Jean-Pierre Torrell, and James Weisheipl (10). Prudlo’s attempt
to occupy of a virtuous middle ground between these two extremes also implies
(and at times explicitly levels) criticism against them.
Inspired in part by the method used by Augustine Thompson, O.P., in his
2012 “new biography” of Saint Francis of Assisi, Prudlo carefully distinguishes
the historical sources (William of Tocco, Bernard Gui, Pietro Calò, Tolomeo of
Lucca, the canonization hearings, and the Vitae fratrum) for the various narrated
episodes in Thomas’s life (usefully enumerated in a chart in Appendix B). Prudlo
generally acknowledges a historical basis for these tales of Thomas, but strips
them of hagiographic additions and interprets them critically. For example, he
readily admits that Thomas as a toddler probably mouthed a piece of paper on
which “Ave Maria” was written, but he declines to interpret the episode (as
Thomas’s hagiographers did) as portending Thomas’s Marian devotion (36).
More controversially, he questions whether Thomas’s observable, frequent,
mental withdrawal from social converse into states of abstraction was properly
lauded by his hagiographers as virtuous. “Thomas had faults, often masked by
his early admirers as virtues,” Prudlo insists (12).
Prudlo diagnoses these putative faults as symptomatic of a clinically defined
condition. Although he rejects Rudolph Bell’s ascription of anorexia nervosa to
medieval women mystics as a misguided anachronism (271), he does not
hesitate to propose that Thomas suffered interpersonally (as many highfunctioning academics do) under the limitations of Autism Spectrum Disorder
(ASD) (270-85). Prudlo modestly delays presenting his “hypothesis” about
Thomas’s personality until late in the book, so that it does not detract from, but
actually enhances, his overarching portrait of Thomas as a truly remarkable
human being whose nature was not destroyed, but perfected by grace, and who
successfully found a way “to negotiate the narrow path to a life of holiness that

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all around him recognized and that was, at length, confirmed by the universal
church” (285). Although Prudlo insists, “This will be no hagiography” (5), his
down-to-earth portrait of Thomas becomes, in the end, the story of a saint
worthy of a double canonization for the holiness of his life and for the truth he
taught.
Prudlo’s critique of hagiography is unequally matched by his criticism of
“exceptionally academic” biographies. “Many of the fine studies of St. Thomas
have a particular downside,” according to Prudlo, because “they are really more
about Thomism than about Thomas,” and simply use “a chronological
framework to drill into his thought” (10). The assertion rings true, but this book
supplies “a genuine feel for Thomas’s thirteenth-century context” (ibid.) at the
cost of giving only a relatively superficial and somewhat repetitive account of
his theology, which Prudlo broadly characterizes as “rational,” “humanist,” and
“incarnational” (because of Master Thomas’s doctrine of human nature’s
substantial unicity as a hylomorphic composite of body and soul). This
shorthand treatment is perhaps unavoidable in a book that ambitiously names
itself “A Historical, Theological, and Environmental Portrait,” but it leaves too
vague the specific grounds for the high-stakes theological contests between the
Franciscans and Dominicans to which Prudlo refers (see, for example, 126-27,
219-21). His somewhat impressionistic account of Thomas’s theology also risks
leaving the impression that his doctrine was more static than it actually was,
belying its development over time.
Prudlo rightly names the big issues and disputed questions of Thomas’s time,
but his laudable endeavor to foreground Thomas himself as a historical person
would have benefitted from the addition of at least one chapter—a case-study
of sorts—showing Thomas’s mind at work to answer systematically a particular
theological question. Prudlo’s best effort in this regard concerns Thomas’s
defense of the orthodoxy of the mendicants’ way of life and pursuit of holiness
(140-42, 211-16). In the dispute with the secular masters at the University of
Paris, Thomas’s “vindication of the mixed religious life of the mendicants stood
out as an obvious moment of victory for a besieged cause,” writes Prudlo (212).
Indeed, he opines, “Thomas’s answers in this debate provided a fundamental
basis for his later canonization” (8).
The book comprises seven chapters and a conclusion. Chapter 1, “The
World Thomas Found,” provides a dramatic opening by describing the shifting
politics of the geographical region where Thomas was born, the Aquinas castle
at Roccasecca being “in close proximity” to the famous Benedictine Abbey of
Montecassino and also “perched nearly halfway between Rome and Naples, just
inside the Kingdom of Sicily and on the border of the Papal States” (31). In
Prudlo’s narrative, this location explains and symbolizes the conflicted loyalties
of the Aquinas family, which had blood-ties to the German emperor, Frederick
II, but also pro-papal inclinations.
Chapter 2, whimsically entitled “Beggars or Choosers? The Genealogy of a
Vocation,” chronicles Thomas’s boyhood as an oblate at Montecassino, his early
studies at the University of Naples, his encounter there with members of the

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recently founded Order of Friars Preachers, his decision to join the Dominicans
(the “beggars”) rather than the Benedictines (the “choosers”), and his abduction
en route to Bologna at the order of the Emperor. Thomas’s fidelity to his
Dominican vocation and to his studies while under house arrest with his family
at Roccasecca finally won out, securing his mother’s permission for him to
return to the Dominicans in Naples.
Chapter 3, “On the Shoulders of Giants,” describes Thomas’s studies at the
University of Paris (1245-48) and his further studies with Albert the Great in
Cologne. The chapter dazzles with the names and titles of the works that
Thomas read, on the premise that “in order to understand Thomas, we must
understand his predecessors” (76), especially the authorities whom the
Dominican Master later cites. Besides the sacred Scriptures, Prudlo emphasizes
the writings of Augustine, Boethius, Dionysius, John Cassian, Gregory the
Great, John Damascene, Anselm of Bec, Peter Abelard, Aristotle, Avicenna,
Averroes, Maimonides, Gratian, Peter Lombard, Hugh of St. Cher, and
Raymond of Peñafort.
In chapter 4, “The University Crucible,” Prudlo first describes the University
of Paris as a historical institution in an urban setting, using the student riots of
1229, the interventions of the Queen Mother and the bishop of Paris, the strike
of the University Masters, and the temporary closure of the university to set the
stage for the conflicts to follow—in particular, those that arose in 1253 between
the mendicant masters, on the one hand, and the secular masters, on the other.
Prudlo pairs this institutional crisis with an intellectual one, set afoot by the new
translations of Aristotle’s works, but he emphasizes the political maneuvers,
publications, civil unrest, and public disputes in Paris against the background of
which Thomas was licensed to incept as a Regent Master in 1256.
As Prudlo explains at the start of chapter 5, the Dominican scholars at the
University of Paris were a mobile group; the Masters in succession each held a
chair for a single term, then surrendered it to another. At the end of a four-year
term at Paris, Thomas thus became an itinerant professor, entrusted by Humbert
of Romans with the task of evaluating and furthering “the order’s practices
regarding academic work” (152). Chapter 5 features three places on Thomas’s
itinerary: Naples, Orvieto, and Rome.
Appointed Preacher General in 1260 and supplied with a socius (Reginald of
Priverno) to serve as his permanent companion, confessor, and secretary,
Thomas became the conventual lector (resident professor) for the Dominican
house in Naples, where he wrote most of the Summa contra gentiles. Prudlo
paints a realistic picture of Thomas as a participant in the community life of the
friary: its hours of prayer (especially Compline), silences, meals, recreations,
chapters of faults. Reassigned as lector in 1261 to the priory at Orvieto, Thomas
obediently took up residence in a “backwater” (175) town that “became—
almost overnight—the center of Christendom” (177), when Pope Urban IV
chose it as residence for the papal curia. Prudlo happily attaches a double
meaning to the phrase “the miracle of Orvieto” (174), which he uses to refer
both to Thomas’s providential contact with leading churchmen in Orvieto and

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to the Eucharistic miracle at Bolsena, later venerated at Orvieto, that was “tied
into the foundations of the Feast of Corpus Christi” (178). He suggests that
Orvieto was also a graced site of intellectual and spiritual transformation for
Thomas—the place where he composed the Catena aurea on the Gospels and
the Office for the Feast of Corpus Christi. From Orvieto, Thomas was assigned
to Rome in 1265 to establish there a studium personale under his directorship,
the forerunner for the Angelicum. That school in Rome, writes Prudlo, became
“Thomas’s experimental laboratory where all of his previous experience would
come together to create his theological masterpiece: the Summa Theologiae”
(191).
Chapter 6 describes Thomas’s recall in 1268 to Paris to take up his second
regency there at a time of crisis. As Prudlo tells the tale, the “nascent Thomistic
synthesis” was under attack by “three rival systems” (199): that of the secular
masters (led by Gerard d’Abbeville, taking up the fallen mantle of William of
Saint Amour); that of the Augustinians (led by the Franciscan Masters John
Pecham and Bonaventure); and that of the radical Aristotelians, sometimes
called the Latin Averroists (led by Siger of Brabant and Boethius of Dacia).
Prudlo describes Thomas as working extremely hard during this second
regency both to answer his opponents and to fulfill his regular teaching
responsibilities as master of the sacred page: “The taxing schedule was
superhuman” (206). Thomas’s academic work came to a sudden end when he
was again in Naples, shortly after the end of his second regency in Paris. In early
December 1273, around the feast of St. Nicholas, Thomas had “some kind of
utterly transformative experience” during the celebration of Mass, after which
“he refused to work or to teach or to write anything further” (240). Prudlo
concludes: “The most likely diagnosis is a combination of physical and
psychological collapse that led to a breakdown” (241). Chapter 6 ends with a
brief account of the last days and hours of Thomas’s earthly life, his reception
of the Eucharist, and his holy death at the Cistercian monastery of Fossanova.
Unlike most modern biographies of St. Thomas, Prudlo’s does not end with
Thomas’s death. Chapter 7 narrates and analyzes the local cult of, and the
miracles attributed to, Thomas at his burial place. It then discusses the double
canonization of Thomas, first as a saint in 1323 and then, with the passage of
time, of Thomas’s theological teaching, especially as it was rendered canonical
for the Friars Preachers (see 293-94) and, later, by Pope Leo XIII in Aeterni
patris (1879). Prudlo’s Conclusion implies the need for these two canonizations
of holy life and of scholarship to be viewed as integral to one another: “It is
Thomas who could make his lecture hall and his study a place of holiness, a call
to all today who live the life of the mind” (304).
ANN W. ASTELL
University of Notre Dame
Notre Dame, Indiana

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What is a Person? Realities, Constructs, Illusions. By JOHN M. RIST. Cambridge:
Cambridge University Press, 2020. Pp. 294. $34.99 (cloth). ISBN 9781-108-47807-6.
In this book, John Rist engages a number of contemporary controversies and
historical reflections about the human person. He also offers a development of
what he calls the Mainline Tradition of reflection on the human person, which
was built up from Greek philosophy and biblical theology. Thomas Aquinas’s
understanding of the person is a signal representative of this Mainline Tradition,
a tradition that Rist argues was augmented and further perfected by Edith Stein.
Against this Mainline Tradition, what could be called the Modern Tradition
rejects God (and therefore the human imago dei), replaces the immaterial soul
with mind as an epiphenomenon of matter, and considers autonomy to be the
ground of human worth. John Locke’s conception of a person as “a thinking
intelligent Being, that has reason and reflection, and can consider it self as itself,
the same thinking thing in different times and places,” is a textbook representative of this modern tradition. Rist writes with flair and authoritative
expertise, especially about the ancient world in which the concept of a “person”
did not play the central role that it came to occupy in the Christian West.
It is unexpected, therefore, that the treatment of Boethius, who gave to us
perhaps the most canonical definition of person in the Mainline Tradition, an
“individual substance of rational nature,” does not receive an extensive
treatment in this book. By contrast, Aquinas is rightly treated as a pivotal player.
Rist appreciates Aquinas’s view of a person but still considers it incomplete. The
gaps in this view include a lack of an adequate and Augustinian appreciation of
the role of history and autobiography (even if unwritten) in understanding an
individual person as well as an overemphasis on matter as the cause of
individuality.
Rist’s compelling account of the undoing of the Mainline Tradition of the
person begins with Scotus but intensifies with Descartes who holds “we can
employ the material world as is appropriate to the nature of its individual parts
and thus make ourselves ‘masters and possessors of nature’. And since even the
human body is non-mental, that too at least in theory is mere matter to be
manipulated” (98). Locke continues the disintegration of the person by considering us as the owners of our bodies (an implicit body-self dualism), and by
positing a concept of the person in terms of psychological properties with
continuity over time. Persons are those who can be held responsible for their
actions rather than individual members of a species. Later thinkers, such as Peter
Singer, will use Locke’s view of “person” in a radically new way. “Person” refers
no longer to individuals who can be held responsible for their actions, but rather
to individuals who are part of the moral community deserving of respect, fair
treatment, and basic rights.
Once the person is understood as a collection of psychological qualities such
as memories and desires, the person is inherently a bundle ever in flux, for these
psychological qualities change, indeed can change quite radically. In David

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Hume we find “both God and soul absent, the older concept of the person,
painstakingly built up over centuries, has more or less disappeared” (125). If a
“person” is a bundle of thoughts, desires, and memories, which are always in
flux, personal responsibility may likewise be unstable. With a humor that makes
its appearance frequently in the book, Rist writes, “A man declines to pay his
debt because he is now not the person who incurred it. At this point, however,
the lender gets angry and strikes his debtor, and when the other complains, tells
him that he is not the same person who struck the blow” (31).
Yet the moral, legal, and political order require stability of persons as well as
a ground for respect for persons. Aspects of the Mainline concept of person are
expressed in the Declaration of Independence: “We hold these truths to be selfevident, that all men are created equal, that they are endowed by their Creator
with certain unalienable Rights, that among these are Life, Liberty and the
pursuit of Happiness.” It is God who grants us our dignity. Rist writes, “the
Declaration of Independence, in bestowing universal and inalienable rights, still
excluded women and slaves from the beneficiaries” (86-87). But in Our
Declaration: A Reading of the Declaration of Independence in Defense of
Equality, Danielle Allen argues that “men” does not in fact refer simply to white
male adults. She notes that the original draft written by Jefferson contains a
paragraph about the violation of the natural rights of slaves. Allen writes,
“Jefferson talks about markets where ‘MEN,’ which he capitalizes, are bought
and sold. In other words, he is calling the slaves ‘men.’ And when he does this,
he can’t mean males only, because those markets were for men, women, and
children. So when, in the second sentence, he writes that all men are created
equal, he must mean all people—whatever their color, sex, age, or status” (154).
Not just Jefferson but other founders like John Adams, as well as Abraham
Lincoln (who might be considered the second founder of the United States),
understood the Declaration as upholding the universal rights of all human
beings—white and black, male and female alike. The Declaration is the political
ideal and the moral standard against which the imperfect social embodiments
of law frequently are found wanting.
Rist argues that contemporary culture has two different competing senses of
the term “person,” both of which find some purchase in our time. The Mainline
Tradition of figures like Boethius and Aquinas is relatively stable but incomplete, for it fails to recognize essential aspects of personhood. On the other
hand, the Modern secularist account of John Locke and David Hume is more
flexible, more historical, but more exclusive in as much as it disqualifies some
individual human beings (the young, the old, and the mentally handicapped)
from basic moral protection.
In turning to more recent philosophers, Rist comes to the surprising conclusion that analytic philosopher Derek Parfit and continental philosopher
Martin Heidegger share striking similarities in their approach to the question,
what is a person? But the most influential recent figure in Rist’s book is not
Parfit or Heidegger but Edith Stein. Stein’s account is an advance on Aquinas’s
because “she holds that matter, by itself, cannot explain individual human

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characteristics and thus our individual nature. . . . And that points to a further
conclusion, to be taken as fact: that basic difference between males and
females—leaving aside between individual males and females—cannot be
explained solely by differences in unspecified human matter; highly individualized human matter is required” (231-32). Stein helps Rist to develop the
Mainline view in other respects as well: “If my revised version of Stein’s view
holds, we have added a further building block to the Mainline account of the
person as a conjunction of matter with an individual soul: a specifically human
conjunction but uniquely individual as the concretization of a unique person
generated by the fusion of an individual sperm and ovum. Such an account can
explain not only our plurality as individual members of the human set but also—
and from conception—our individuality, we being necessarily more than
substitutable units variegated only by differing historical experiences” (234).
This richer conception of the human person is needed in order to adjudicate
controversies that arise in our shared social life. “In general, such problems are
resolved—at least in appearance—by applying social norms: it is socially
harmful, we may assert, for a man to be polygamous. All such determinations
will depend on the kind of individual human being one assumes to be the perfect
(even if unrealizable) exemplar” (237). What we ought to do is necessarily
connected to who we are.
Towards the end of the volume, Rist focuses his sage attention on gender
issues. He holds that atheism awoke Christians from their dogmatic slumber
about these issues by interrupting an unreflective traditionalism which is not
directly connected to revelation. A legitimate conservation of the faith once
delivered to the saints inadvertently also conserved Aristotle and other pagan
reflections on femalekind which uneasily fit with the radical respect Jesus
showed women. Rist holds that revelation itself offends against certain kinds of
gender equality. “The unequal relationship of Christ and the Church, as evoked
by Paul in Ephesians, fits better with older traditions about marriage as between
unequal persons than with a modern understanding marriage as of equal—
though essentially from identical—persons” (229). And yet someone as
traditional as Aquinas argues, “if a husband were permitted to abandon his wife,
the society of husband and wife would not be an association of equals, but,
instead, a sort of slavery on the part of his wife” (ScG III, c. 123). Aquinas notes
that “friendship consists in equality,” and that “there seems to be the greatest
friendship between husband and wife” (ScG III, cc. 124 and 123).
Although men and women are equal (in terms of basic dignity as well as basic
duties), we need not assert that they are exactly the same in other respects nor
that these differences are always and only the result of patriarchal oppression.
“Time and again Stein returns to the theme that there are male souls as well as
female souls, just as there are male bodies as well as female bodies” (244). The
differences between men and women, not just in body but in soul, lead to
significant differences in behavior between the sexes. “Moving to the capacities
found more typically in one sex than the other, she [Stein] identifies male
behaviour as more focused, more single-minded and more appreciative of the

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abstract, while women are normally more ‘personal’ (187, 188, 190, 255), their
interests being more ‘holistic’ in that they have a ‘special interest in the living
concrete person’ (101): ‘indeed as much [in] their own personal life as [in] other
persons and their personal circumstances’” (245). Stein’s view finds some
empirical support in Steven Pinker’s The Blank Slate, which notes that on
average women are more interested in people and men are more interested in
things. These differences in interest do not decrease in societies with greater opportunities for women, places like Sweden in comparison to places like Algeria,
but rather increase. This fact suggests that when women have the freedom to
select their own occupations, that is, where “patriarchy” is least powerful, the
differences between men and women increase rather than decrease (Zhang,
Lingshan, et al. “Are Sex Differences in Preferences for Physical Attractiveness
and Good Earning Capacity in Potential Mates Smaller in Countries with
Greater Gender Equality?”, Evolutionary Psychology 17, no. 2 [2019]). Rist
notes that Stein grounds differences such as these in different roles that males
and females have in human reproduction and nurture of the very young.
What is a Person? is the fruit of enormous learning and a mind capable of
contextualizing philosophers differing in language, culture, and historical
contexts in a clear, memorable style of exposition.
CHRISTOPHER KACZOR
Loyola Marymount University
Los Angeles, California

John Henry Newman on Truth and Its Counterfeits: A Guide for Our Times. By
REINHARD HÜTTER. Sacra Doctrina Series. Washington, D.C. The
Catholic University of America Press. 2020. Pp. xiii + 267. $24.95
(paper). ISBN 978-0-8132-3232-4.
“From the time that I became a Catholic, of course I have no further history
of my religious opinions to narrate. In saying this, I do not mean to say that my
mind has been idle, or that I have given up thinking on theological subjects; but
that I have had no variations to record, and have had no anxiety of heart
whatever.” With these words, John Henry Newman began the final chapter of
Apologia pro Vita Sua (1865), addressed to a Protestant public to explain his
conversion from the Church of England to the Catholic Church. These words
might express the confidence of Reinhard Hütter’s final chapter, too, an
“Epilogue” which explains his own conversion from Lutheranism to Catholicism. One difference between the Apologia and Hütter’s book is that the latter
is written by a Catholic for Catholics, quoting conciliar documents and a
plethora of papal encyclicals. There is nothing wrong with such an approach in

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a volume written by a professor at The Catholic University of America, in a
series entitled “Sacra Doctrina” and published by The Catholic University of
America Press. But it was not Newman’s approach in the Apologia nor in many
of his controversial works that Hütter quotes. The Apologia was teeming with
Protestants, even as it criticized the one (Charles Kingsley) who accused Newman of dishonesty: from Bishop Joseph Butler, the Anglican theologian whom
he credited with two of his most important theological principles, to the
Anglicans he still called his friends, to the court of public opinion in which he
presented his case so persuasively. Where Hütter is less persuasive than
Newman is not in his prose (which is lucid), but in courting the opinion only of
fellow Catholics.
The Prologue argues that the canonized cardinal can speak as our
contemporary because of his threefold characterization of the predicament of
the age: “the spirit of liberalism in religion, the usurpation of religion and faith
by rationalism, and the unfettered rule of the principle of private judgment in
religion” (1). Newman began criticizing each of these three while still the chief
spokesman for a catholic renewal of the Church of England, and though faced
with a different set of historical circumstances from those articulated in Hütter’s
epilogue, he like Hütter eventually found relief from the continual need to
resort to “private judgment” by becoming a Catholic. Today’s prevailing
predicament is, in Hütter’s phrase, “the unfettered autonomy of the sovereign
self” (3)—a freedom (conceived negatively) summed up in the words of Justice
Anthony Kennedy as, at heart, “the right to define one’s own concept of
existence, of meaning, of the universe, and of the mystery of human life”
(quoted ibid., repeated on 216). Against such a counterfeit of human being and
purpose, Hütter presents Newman’s views on the topics of Conscience, Faith,
the Development of Doctrine, and the University—or he almost does. For in
Hütter’s view, what Newman “initially brought to light, described, and
tentatively explained in the context of discovery” as psychologist, phenomenologist, and controversialist needs supplementing with Aquinas in “the
theological context of justification” (19). That Newman read Aquinas is not in
doubt; however, it seems to this reviewer unlikely that he read Aquinas in the
same way Hütter does. Nevertheless Hütter’s method will not, he admits,
“contribute to the ongoing exegesis of Newman” (20).
The drawback of this method can be seen in chapter 1, where a brief
encounter with Newman’s Letter to the Duke of Norfolk is coupled with a
discussion of Aquinas on synderesis and conscientia. This chapter pits the
theonomic conscience against its counterfeit, either the counterfeit presented by
the knockers of conscience who (in Newman’s words) see it as “an imagination,” an “irrational” inhibition of “freedom of will” (28), or the counterfeit
of boosters (such as Chief Justice John Roberts) of “the right of conscience” to
self-determination (30). Were one attempting an exegesis of Newman on
conscience, one might relate his thought to Bishop Butler, who called
conscience “the guide assigned us by the Author of our nature.” Butler’s work,
The Analogy of Religion, was common reading at Oxford for both Newman and

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William Gladstone, the sometime British Prime Minister to whom the Letter to
the Duke of Norfolk was a reply. (Gladstone even produced an edition of
Butler’s works, which makes one ponder whether, considering politicians today,
we can indeed claim Newman’s age as our own!) Nevertheless, Hütter is right
that, briefly in the Letter, Newman “draws on a distinction at the very center of
Aquinas’s doctrine of conscience, between, on the one hand, the existence of an
innate first principle and the first precept—Aquinas calls this synderesis—and,
on the other, the intuitive bearing of the first principle and first precept upon a
particular case” (33)—conscientia. In order to avoid error, this last, which
Hütter translates “knowing together,” requires instruction and counsel from
others, as well as self-examination. This reliance on theonomy within the
individual, and the heteronomy of the Church’s instruction and counsel
without, is opposed to its autonomous counterfeit; and it seems reasonable that,
as Hütter argues, Newman meant the same in his famous toast to conscience
first and to the pope second. The remainder of the chapter ranges beyond the
scope of Newman into twenty-first-century politics and culture, though it ends
with some rich appendices on conscience in Newman and other thinkers.
Chapter 2, concerning faith, begins with a strong critique of the late-modern
West in which “transhumanism—and outgrowth of the sovereign subject—and
posthumanism—the reductive understanding of the human being as superprimate—coincide” in a sovereign subjectivity that has “only two sides, its agent
and its object” (91). Newman’s address to both Protestants and Catholics soon
after his conversion, against those in whose sight “our offence is that of
demanding faith in the Holy Catholic Church,” becomes grounds for criticizing
any ecumenism that does not have as a condition “holding fast in one’s assent
of faith to the formal object or motive cause, the first truth, which includes the
living apostolic authority of the Catholic church” (117, 118). Although Hütter’s
exposition of Aquinas on divine faith is (so far as I can judge) flawless, it
nevertheless appears misplaced. In the Apologia, Newman stated that it had
been fellow Oxford Movement leader John Keble who strengthened Bishop
Butler’s probabilism into an account of faith as assent to the divine object to
whom “faith and love are directed”—an account in which “the argument from
Probability, in the matter of religion, became an argument from Personality,
which in fact is one form of the argument from Authority” (Apologia, uniform
edition, 19). Not only does this Anglican view of faith contradict Hütter’s
description of “classical Protestantism” precisely because it does not substitute
the “living apostolic authority that is authorized and guided by God to communicate God’s revelation” (which Keble affirmed was located in the episcopacy) with private judgment based upon sola scriptura (102, which Keble
criticized as “ultra-Protestantism”), neither does it accord with the Thomistic
account of divine faith that Hütter presents. Moreover, Newman affirms
Keble’s account as “beautiful and religious, but it did not even profess to be
logical; and accordingly I tried to complete it” (Apologia, 20). In his Anglican
works he attempted to complete the probability-based account of faith, a very
different logical mode from Scholasticism. C. Michael Shea (who appears in a

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footnote of the first appendix to this chapter, 122 n. 64) has expertly shown
that Newman learned and contributed to Scholastic accounts of the faith in the
year he spent in Rome after his conversion. But even Hütter, in the chapter’s
useful second appendix, on certitude, admits Butler’s ongoing significance in
Newman’s masterwork, the Grammar of Assent (Butler also appears in a single
footnote, 126 n. 69).
The third chapter, on development of doctrine, is shorter and Aquinas only
appears in a fascinating appendix on “Francísco Marín-Sola’s Thomist
Reception of Newman.” The bulk of the chapter pits Newman’s account of
development against its counterfeits: the viewpoint of the “ecclesial antiquarian” on one hand and the “ecclesial presentist” on the other. Surprisingly,
the 1859 essay “On Consulting the Faithful in Matters of Doctrine” makes no
appearance (here or in the brief intellectual biography in the Prologue). This
essay is considered by many to be Newman’s signal contribution to the
argument that reception by the faithful is evidence of a genuine doctrinal
development.
Hütter is on home territory when in the fourth chapter he compares
Newman’s “ideal” of the university (195) with the secular, utilitarian, profitdriven multiversity of today. Today’s counterfeit is the fulfillment of what
Newman described in the 1852 Dublin Discourses (which Hütter rightly shows
cannot be confused with the Idea of a University, 168 n. 1) as a Baconian
polytechnic. Hütter makes a good case for interpreting the “philosophy” that
Newman described as the “architectonic science,” which in the genuine
university reveals the unity of “the whole circle of secular knowledge,” to be
the first philosophy of Thomistic metaphysics, whose “apex is natural theology”
(174). It is important that Hütter stops at natural theology, though, because in
Newman’s Catholic University in Dublin there were no courses on revealed
theology for undergraduates, confined as they were (in Newman’s words) to
“apply their minds to such religious topics as laymen actually do treat.” Hütter
argues that such confinement was in response to bishops’ concerns (185 n. 36),
but it should be pointed out that it was also Newman’s experience as a student
and teacher at Oxford that revealed theology was the domain of clergy. Later
in the chapter, Hütter’s account of the “architectonic science” becomes more
expansive than Newman’s: “Only with theology as the keystone of the arch of
university disciplines will the arch achieve the widest possible scope, will the
university remain open to a maximum of interrelated and complementary
sciences, will a university education remain in all areas of knowledge essentially
philosophical, and will universal knowledge as an end in and of itself be
intelligible and desirable” (198). Hütter’s evident passion in this chapter is
partially explained by an autobiographical footnote giving his different
experiences as a student, teacher, and leader in institutions of higher education
in Germany and the U.S.A.: “My commitment is simultaneously the source of
my love for John Henry Newman’s The Idea of a University and of my criticism
of the modern research university” (210 n. 71).

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The personal dimension of Hütter’s book is something shared with
Newman’s writings. Warning against the Modernists’ misunderstanding of
Newman, Hütter concedes: “What makes Newman vulnerable of being coopted in such a way is . . . his profound personalism, which can easily be
misrepresented as an endorsement of modern individualism. Yet it is precisely
his focus on the concrete reality of the human person, intellectual and essential,
that keeps Newman from becoming a mere reactionary in modern times” (5). I
entirely agree that this is true of Newman; but how much of Newman’s person
appears in this book? Although I heed Hütter’s concern about “that field of
Newman scholarship that pursues an ever-more minute reconstruction of
Newman’s thought in its own historical context” (20), it is nevertheless
Newman’s person that we need to meet in order to discern his peculiarities of
thought, some of which result from the concrete circumstances of the first half
of his life that he brought with him to Catholic theology. We cannot rely on
Aquinas to fill in the gaps, or else the Newman we meet is also a counterfeit.
BENJAMIN J. KING
University of the South
Sewanee, Tennessee

The Nature of Human Persons: Metaphysics and Bioethics. By JASON T. EBERL.
Foreword by CHRISTOPHER KACZOR. Notre Dame Studies in Medical
Ethics and Bioethics. Notre Dame, Ind.: University of Notre Dame
Press, 2020. Pp. xvi + 405. $75.00 (hard). ISBN 978-0-268-10773-4.
Questions of bioethics concern human persons as animals, that is, as beings
who are born and die, who become ill or injured and who recover or decline,
who are not always strong and independent but who live and die in a web of
interdependencies. At the same time, it concerns human beings as rational, relational, and cultural: as capable of making decisions (for themselves or for
others, by themselves or with others) that can be judged as good or bad, as
ethical or unethical.
How one does justice to the animal and rational aspects of human nature
and understands them together as aspects of a unified being is far from
straightforward. Unfortunately, much academic bioethical discussion launches
straight into the ethical dilemmas of clinical medicine with little prior reflection
on the fundamentals of moral philosophy and even less on the metaphysics of
the human person as animal and rational. Jason Eberl is to be commended in
seeking to address this lacuna and in bringing to it the resources of the
Thomistic intellectual tradition. Eberl brings Thomas Aquinas into conversation
with a number of contemporary English-speaking philosophers and seeks to

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show that Thomas provides a satisfying via media between substance dualism
and reductive materialism.
The book has eight chapters, the first four of which concern the question
“What am I?” framed as a question of human nature and of personal identity.
Eberl lists nine desiderata (his term) that ought to be satisfied by any account of
human nature. He then discusses hylomorphism (chap. 2), varieties of dualism
(chap. 3), and varieties of materialism (chap. 4) before coming to the conclusion
that Thomistic hylomorphism satisfies the desiderata more than do the other
accounts he has surveyed.
Chapters 5 to 7 apply this account of the human person to the questions of
when human beings begin to exist, when they die, and whether there could be
hope for life for human persons beyond death. Chapters 5 and 6 do not address
bioethical questions per se as “responses to the various bioethical issues at hand
require combining metaphysical conclusions with a particular ethical theory and
taking various values into account” (17). Nevertheless, where one’s actions
might end the life of some being, it is clearly ethically relevant to know whether
that being is a human person. In contrast, it is much less obvious how chapter
7 relates to bioethics. This chapter does, however, provide important insight
into Eberl’s theological anthropology.
The final chapter, comprising a mere 10 pages (from a book of 260 pages),
is the only chapter to discuss bioethical topics directly: abortion and care of
people in a persistent vegetative state (PVS). Its brevity causes problems. The
impression is given that cases of abortion are either unintended and
proportionate or both “directly intended” and “disproportionate to the human
person’s death” (255). There is no discussion of abortion where the death of
the unborn child is unintended but the good that is intended, while serious, is
not a matter of life-or-death, no discussion of cases where the death of the child
is intended but the good aimed for is a matter of life-and-death, and no
discussion of cases such as craniotomy where death may be unintended but
bodily harm is intended or at least, a bodily invasion that will in fact be lethally
harmful. In relation to PVS there is no mention of the teaching of John Paul II
(March 20, 2004) on the significance of providing nutrition and hydration or
discussion of whether there are forms of care that are in principle obligatory.
Eberl acknowledges that the chapter provides only “a brief treatment of these
questions” but promises that “more in-depth treatments may be found in the
works cited here” (250). Regrettably, the endnotes to this chapter are also
extremely cursory (less than 2 pages from an expansive 84 pages of endnotes).
In relation to the rest of the book, the strongest chapters are chapter 5 and
6 on when human life begins and when (bodily) human life ends. These are
worth consulting by anyone concerned with these questions. However, the
argument of the book as a whole suffers from reading Thomas through a narrow
lens shaped by less-interesting thinkers. In his foreword, Christopher Kaczor
states that the book “surveys and critiques all the major (and the minor)
alternatives to its own position, including animalism, constitutionalism, fourdimensionalism, substance dualism, and emergent dualism” (xi; emphasis

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added). However, while Kaczor (not Eberl himself) presents this survey as
“comprehensive” (x), a more fitting adjective would be “parochial.” Eberl
himself observes that all of the views he has surveyed “despite their respective
nuances, may thus be termed ‘neo-Lockean’” (129). There is no serious
engagement with ancient or medieval philosophers other than Thomas. Even
Aristotle is brought in rarely and mainly as a foil to Thomas. Among twentiethcentury philosophers, none are included outside this “neo-Lockean” tradition.
To take just two examples, there is no mention of Ludwig Wittgenstein or of
Martin Heidegger. It is a lazy criticism to point out what a book does not
contain, for no book can cover everything, but it is important to recognize that
Eberl is mediating between Thomas and a very particular tradition of
Anglophone philosophy, and this shapes his reading of Thomas as much as it
does his critique of that tradition.
A few examples suffice to show the problems with the approach taken in the
book. Eberl begins by listing nine “desiderata” for an account of human nature.
This is a curious method which begins with propositions desired to be true and
tests theories or arguments on the measure of whether they support these
conclusions. Such a method runs quite counter to the Thomistic method of
considering arguments for and against (or rather, against then for) propositions
and then going where the arguments lead, even when these conclusions appear
unpalatable or unconventional. Perhaps this is overinterpreting the word
“desiderata” and Eberl could be construed not as listing propositions that it
would be desirable to believe but as setting out criteria for whether an account
of human nature is adequate to reality. However, if these propositions are
supposed to mirror fundamental aspects of human reality which can be known
a priori or with little argument or which are evident to the senses and widely
acknowledged, then this is certainly not true of the first proposed desideratum:
“it is possible for human beings to survive bodily death” (135).
It is very strange to start with the possibility of life after death as this seems
the least evident aspect of human nature. Aristotle, who is the primary
philosophical source for Thomas, was notoriously obscure about what happens
to the human soul after death. A more fundamental problem is the way the
proposition is framed. It concerns not the possibility that human beings could
have life after or out of death but the possibility that human beings could survive
death. The claim that this is possible is reiterated throughout the book and
especially in the extensive discussion in chapter 7.
Thomas, in line with constant Catholic tradition, held that the human soul
is not destroyed when the body dies (STh I, q. 75, a. 2; and q. 75, a. 6). This
was not only a theoretical belief for him but was expressed in prayers to the
saints and prayers for the souls in purgatory. The earliest biographies attest that
the soul of his sister appeared to him to ask him to pray for her (Bernard Gui
20, William of Tocco 44) and the duty to pray for the dead is expressed
throughout his writings (e.g., Collationes super Credo 5). Nevertheless, Thomas
stated very clearly that the separated soul is not a human being (STh I, q. 75,
a. 4) and does not fulfill the definition of a person. He was also clear that in the

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incarnation God became a human being and that this human being ceased to
exist between his death on the cross and his resurrection (STh III, q. 50, a. 4).
Thomas thus denied that the human being survives death as a separated soul.
The human being has hope for life after death only because of the promise of
the resurrection.
Eberl is aware that he differs from the view that Thomas maintained. Nevertheless, Eberl argues that “the survivalist thesis” is defensible on Thomistic
hylomorphic principles and indeed is something that Thomas “could have—and
arguably should have” held (232). On Eberl’s account, the separated soul is a
person (224), a human being (222), and even an animal (240), and is the same
person, human being, and animal that existed before death. This metaphysical
view has moral implications. In his critique of substance dualism, Eberl states
that such views “raise the morally relevant question of whether death—and a
fortiori killing—can really be understood as an evil for the person who allegedly
‘dies’” (210). As Eberl also denies that the human being “dies,” in the sense of
ceasing to exist, this is a moral challenge for his own view. On Eberl’s account,
killing takes the life of the body but does not end the life of a human being. It
is a serious but a relative harm.
Eberl departs still further from Thomas, and embraces a serious theological
error, in relation to God’s involvement in the resurrection. In chapter 7, Eberl
is, quite reasonably, critical of attempts to invoke divine intervention as an ad
hoc solution to puzzles over how someone raised from the dead could be the
same human being. However, having shown how Thomistic hylomorphism
provides a satisfying resolution of this problem, Eberl enunciates a principle
that goes far beyond anything in the Catholic tradition: “a metaphysical account
of postmortem survival is preferable if it minimizes the extent to which God
must be actively involved in the process” (214; emphasis in the original); “I
submit that a mark of a theory’s superiority is that it involves God having to do
the least amount of supernatural work to ensure that the numerically same
human being persists through death and resurrection. Aquinas requires that God
provide ‘raw matter’ for the soul to reinform at resurrection—and thus
resurrection counts as a supernatural miracle—but that is all God must do for
the same human being to be composed of the same body” (245; emphasis in the
original); “the less often a theory has to invoke miraculous divine intervention
to explain putatively everyday occurrences, such as a person passing from death
into immortal life, the stronger the theory” (342 n. 180).
It is hard to know where to start in criticizing this alleged “principle” (211).
In the first place, no created being could remain in existence without God being
“actively involved.” In the second place, the life of grace and human fulfillment
in the glorious resurrection are archetypal of the “supernatural.” In the third
place, the general resurrection is not the reinforming of “raw matter” in this
world, as in the case of Lazarus (John 11:1-44), but concerns the creation by
divine power of a new heavens and a new earth (Rev 21:1). However, these
themes are neglected by Eberl, not least because, of 216 endnotes to chapter 7,
only 1 (n. 199) contains any reference to Scripture! The characterizing of divine

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involvement in the world as “miraculous” and the wish to “minimize” such
“intervention” owes more to David Hume and to deistic forms of natural
theology than it does to Thomas. It reminds one of the complaint of Blaise
Pascal, “I cannot forgive Descartes. In his whole philosophy he would like to
dispense with God, but he could not help allowing Him a flick of the fingers to
set the world in motion, after which he had no more use for God.” The
requirement for “an account . . . that minimizes divine activity” (239) is perverse
as a theological principle in any context but nowhere more so than when
considering the fulfillment of human nature in the life of the world to come.
DAVID ALBERT JONES
The Anscombe Bioethics Centre
Oxford, United Kingdom
St Mary’s University
Twickenham, United Kingdom

The Saint and the Atheist: Thomas Aquinas and Jean-Paul Sartre. By JOSEPH S.
CATALANO. Chicago and London: The University of Chicago Press,
2021. Pp. viii + 166. $30.00 (cloth). ISBN 978-0-226-71943-6.
As a discipline that considers all of being, philosophy can be expressed in a
range of genres, from precise disputed questions, to dialogues, to meandering
essays. But in each genre, philosophical writing tends toward the technical and
the impersonal. The Saint and the Atheist eschews those tendencies. Instead, it
is a series of impressionistic reflections on themes in Jean-Paul Sartre and
Thomas Aquinas, and on the author’s own intellectual life and sociopolitical
predilections. Joseph Catalano is a Sartre scholar, but he wrote his dissertation
on Aquinas. Now, late in his career, having written several books on Sartre, he
returns to the Angelic Doctor to see how he, in company with Sartre, can
reawaken “our original wonder that there is a world and we are in it” (2). He
avoids the often-technical language of both thinkers, seeking to show how the
themes he finds in both are drawn from sources in everyday life. (My own
dissertation director, Jorge Gracia, recommended that I never use technical
language unless I could translate it into perfectly ordinary language. Catalano
follows such advice to a fault; much of the precision achieved by both thinkers’
technical vocabulary is lost in his excessively loose discussions of normal life.)
With its disparate, memoir-like structure, this book does not defend a single
thesis or claim. In this, it is unlike Stephen Wang’s 2009 book Aquinas and
Sartre, which compares and partially synthesizes the two philosophers’ views
with admirable precision. It is also unlike the work of the great Polish Thomists
Mieczyław Krąpiec and Andrew Woznicki, who bring ideas from Sartre into a

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clearly Thomistic, but existentially inspired, philosophical milieu. For those
who wish to see what Sartre and Aquinas may have to say to one another on a
deep philosophical level, I would recommend one of those thinkers. Rather, this
book presents a range of themes, mostly drawn from Sartre but with analogues
in Aquinas, though without much argument or careful consideration of how the
two thinkers’ worldviews precisely fit together. The book’s value, at least for
Thomists, lies not in providing any new insights into Aquinas—indeed, it gets
many things about him wrong, often deeply so—but in that it helps the Thomist
see how Aquinas comes across to a thoughtful, advanced scholar, revealing ways
in which Aquinas is easily misunderstood and places in which Thomistic thought
needs clarification or advancement.
Some already existing familiarity with Sartre is necessary, I think, fully to
appreciate Catalano’s claims. Catalano has interesting things to say about
Sartre—for example, that, contrary to how he is often read, Sartre gives a
prominent place to bodily life in his anthropology (20), and that really to
understand him we need to pay attention to his works on literary themes,
especially his books on Jean Genet (Saint Genet) and Gustave Flaubert (The
Family Idiot) more than his more philosophical works like Being and
Nothingness and Critique of Dialectical Reason. While Catalano ably introduces
some of these ideas, he often writes in a way that presupposes awareness of his
ideas and of the secondary literature debates on them. His other books, such as
Reading Sartre (2010), serve as a much better introduction to the great
existentialist than the current volume.
The Saint and the Atheist opens by asking whether philosophy has produced
anything since the perennial tradition so ably summed up in Aquinas’s work
that genuinely adds to that tradition. Catalano finds something new in the
phenomenological tradition that builds on Husserl, especially in Sartre’s
reflections on human freedom and the way in which we shape ourselves, others,
and the world in general through using that freedom. He spends several
chapters developing the Sartrean theme of “good faith.” To act in good faith is
to believe in one’s freedom and one’s obligations. But human beings can also
avoid their obligations, taking refuge, for example, in art for art’s sake, or in
concern for one’s private property (62-63). Catalano finds parallels to this idea
of good faith in Aquinas’s understanding of synderesis and conscience, which
can be formed in such a way that we take up the task of living out our freedom
well or avoid this call. He makes much of Aquinas’s moral approval of taking
what one needs from others in cases of strict necessity (24). Throughout the
book, this attention to taking others’ property is linked to a paradigm case of
acting in bad faith, what Sartre calls the condition “scarcity” (99). By this, Sartre
does not mean the condition of having less of some good than is needed. Rather,
it is the condition of withholding goods from people when they could be
provided with our current level of technological skill. To have concern for one’s
property when one could use it to help those badly off is an abuse of freedom,
an instance of acting in “bad faith.”

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Yet although Catalano notes a sort of parallel here between Aquinas and
Sartre, he is dismissive of the very foundation that Aquinas gives for his moral
conclusions, the natural law and Scripture. These things, he says, “hardly need
to be mentioned” (24). Rather, he continually returns to parallels between
Sartre and Aquinas on more superficial levels, such as similar things each says
about human freedom or about the discovery of universals on the basis of
sensory, bodily activity. The deeper metaphysical and theological (or atheological) roots of each thinker’s conclusions are routinely set aside. For example,
on Sartre’s view, the world in itself is a mass of unordered events; things only
appear as distinct, and only become ordered in relation to one another through
our free acts of ordering the world. Catalano notes that Aquinas sees in the
ordering of the world and its fit with our cognitive powers a sign of the
providence of God, but then offhandedly recommends that we bracket this fact
(in the phenomenological sense of putting it out of consideration), instead
considering how for both Aquinas and Sartre we are called to take free
responsibility for the world (109-10). The convergence between the thinkers on
this point, I would contend, is superficial and maybe even merely verbal. The
theological basis for Aquinas’s view cannot be “bracketed” without basically
abandoning the Thomistic view; for Aquinas, human freedom only has meaning
and existence within divine providence. This dismissiveness also shows up in
some of the cultural commentary throughout the book—for example, Catalano
dwells at some length, but without much connection to the philosophical
themes of the book, on the Catholic Church’s complicity in evil regimes like
National Socialism.
In addition to freedom and its sociopolitical implications, a major theme of
the book is the status of each person as both an instance of a universal kind and
a unique singular entity. Catalano provides some helpful reflections on concrete
ways in which we find ourselves to have much in common with others, yet also
find others alien to us (41). In what is the most insightful chapter of the book,
he considers how universals arise out of phantasms. On his Sartre-inspired
understanding of abstraction, universal ideas are forged on the basis not just of
sensible forms, but also through cultural, historical, and bodily practices. We
come to grasp the universal “tennis,” for example, through bodily participation
in the practice of playing and watching tennis (67-70). Perceiving, understanding, and abstracting should be understood as activities and tendencies of
the whole person and the whole body; phantasms must be understood much
more expansively than as mere mental images. Similarly, our uniqueness as
persons, on Catalano’s view, arises out of our free acts and our bodily
interactions with others, though he confuses “person” with “personality,”
misreading Aquinas on this terminology (71). We depend on how others look
at us—for example, in objectifying or empowering ways—and speak about us
to receive our own sense of freedom (34). These philosophical points are backed
up with insightful and often convicting reflections on how we raise our children,
and the ways in which we can damage or aid their moral development.

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Yet here again, Catalano either overlooks or dismisses significant features of
Aquinas’s view. On Sartre’s view, according to Catalano, we are not born with
internal sensory or intellectual powers, but must forge these powers and so
become fully distinct persons. He seems to think that on Aquinas’s view we are
just born with these powers, with no further development involved. He
concludes that this is a point where Sartre has advanced beyond Aquinas. But
while Aquinas does think we are born with our powers, it is not as though
Aquinas has a static view of the human person, with no possibility for
development. To think that is to overlook all of Aquinas’s discussion of habit,
virtue, and vice—that is, to overlook nearly his entire ethics! This overlooking
on Catalano’s part is, I think, a genuine lack of awareness of most of Aquinas’s
corpus—for another example, he says that he is not aware of Aquinas ever
discussing relations between Church and state (113). Catalano thinks that what
is important in comparing Aquinas and Sartre on human persons is that they
both take seriously the body and freedom, while not seeing much importance
in the contrast between Aquinas’s hylomorphism and Sartre’s materialism (44)
and drawing a facile, unargued-for similarity between the idea of “nothingness”
that drives Sartre’s notion of freedom and Aquinas’s notion of the soul (76).
Yet for all these misunderstandings and oversights, Catalano is also deeply
aware of important, foundational issues in Thomistic metaphysics. Hence, I
wonder whether his dismissiveness towards the natural-law, theological, and
virtue-ethic features of Aquinas’s thought is ignorance on his part or an actual
bracketing of what he takes to be unfitting with a Sartrean point of view. It is
difficult to tell from the text. He carefully explains the Thomistic view of
analogy, including Cajetan’s view, and Aquinas’s view of nature absolutely
considered, relating these ideas in fruitful ways to the Sartrean view of the
human person as a unique universal singular. Yet again, although he is keenly
aware of some features of the later broader Thomistic tradition, he seems
unaware of others—for example, although he refers to Edith Stein’s
phenomenological Thomism at times, citing its synthetic approach as an
influence on his own work, he seems to fail to see how she (like Sartre) arrives
at a view of persons as uniquely singular.
Perhaps the feature of Aquinas’s thought in which Catalano shows the most
sustained, but unexpected, interest is Aquinas’s angelology. For a work of
engagement with an atheist materialist, and a work which regularly sets aside
any talk of God, angels feature prominently in this work (e.g., 40, 82, 129).
This is, I think, something for Thomists to take seriously: angelology and
anthropology intersect in Aquinas in important ways, and these intersections
should be mined for philosophical insight. For example, while Catalano follows
Aquinas in holding that Plato’s view of human persons would make us too like
the angels, he thinks that Sartre gives us reason to think that human persons,
especially under modern technological conditions, can act as the angels act in
Aquinas: as the ones who decisively guide the development of the world.
There is much to be gained from a confrontation, and even partial synthesis,
between Aquinas’s thought and that of phenomenologists and existentialists like

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Sartre. Catalano’s book reveals some promising points of contact between these
traditions, though these points require much more detailed and precise
development by others really to advance either tradition, or to bring the two
together.
MARK K. SPENCER
University of St. Thomas
St. Paul, Minnesota