METAPHYSICS, BOOK XII
Mobile and Immobile Substance
The Prime Mover
CONTENTS
Lesson 1: Metaphysics Studies Substance
Lesson 2: Three Classes of Substances
Lesson 3:Characteristics of Forms
Lesson 4: The Principles of Movable Substances
Lesson 5: An Eternal Immovable Substance Must Exist
Lesson 6: Eternal Motion Requires An Eternal Mover
Lesson 7: How the First Mover Causes Motion
Lesson 8: The Perfection of the First Substance
Lesson 9: The Number of Primary Movers
Lesson 10: The Number of Unmoved Movers
Lesson 11: The Dignity of the First Intelligence
Lesson 12: God Is the Final Cause of All Things. The Order of the Universe
LESSON I: Metaphysics Studies Substance
ARISTOTLE’S TEXT Chapter 1: 1069a 18-1069a 30
1023. The study here is concerned with substance; for it is the principles and causes of substances which are being investigated.
1024. For if the totality of things is a kind of whole, substance is its first part; and if things constitute a whole by reason of succession, substance is also first, and then quality or quantity.
1025. And in like manner the latter are not to be regarded as beings in an unqualified sense, but as qualities and motions of being. Otherwise the not-straight and not-white would be beings; for we say that they are, for example, “the not-white is.”
1026. Again, none of the other genera can exist separately.
1027. The ancient philosophers testify to this in practice, for it was of substance that they sought the principles, elements and causes. Present-day thinkers [Platonists] however, maintain that universals are substances; for genera are universals, and they say that these are principles and substances to a greater degree because they investigate the matter dialectically. But the ancient philosophers regarded particular things as substances, for example, fire and earth, and not a common body.
COMMENTARY
2416. Having summarized in the preceding book the points that were previously made regarding imperfect being both in this work and in the Physics, in this book the Philosopher aims to summarize the things that have been said about being in its unqualified sense, i.e., substance, both in Books VII and VIII of this work and in Book I of the Physics, and to add anything that is missing in order to make his study of substances complete. This is divided into two parts. First (1023:C 2416), he shows that this science is chiefly concerned with substances. Second (1028:C 2424), he gives his views about the classes of substances (“Now there are three”).
In regard to the first he does two things. First, he states his thesis. He says that in this science “the study,” i.e., the principal inquiry, has to do with substances. For since this science, being the first and the one called wisdom, investigates the first principles of beings, the principles and causes of substances must constitute its main object of study; for these are the first principles of beings. The way in which principle and cause differ has been pointed out in Book V (403:C 760).
2417. For if the totality (1024)
He proves his thesis in four ways. The first proof runs thus. Since substance is prior to the other kinds of beings, the first science should be one that is chiefly concerned with the primary kind of being. He shows that substance is the primary kind of being by using an analogous case in the realm of sensible things, among which order is found in two ways. One kind of order is found among sensible things inasmuch as the parts of any whole have a certain natural arrangement; for example, the first part of an animal is the heart, and the first part of a house the foundation. Another kind of order is found among sensible things inasmuch as some follow others and one thing is not constituted from them either by continuity or by contact. It is in this sense that one speaks of the first and second lines of an army. Hence, just as there is some first part in any whole, and also some first entity among things that follow one another, so too substance is the first of all other beings. This is what he means when he says “For if the totality,” i.e., the universe of beings, is a kind of whole, substance is its first part, just as the foundation is the first part of a house. And if beings are like things that follow one another, substance again will be first, and then quantity, and then the other categories.
2418. But Averroes, failing to consider that this statement is analogical because he considered it impossible for anyone to think that all the other genera of beings should be parts of one continuous whole, departs from the obvious sense of the text and explains it in a different way. He says that by these two orders Aristotle meant the twofold relationship which can be conceived between things. The first is that beings are related as things having one nature and one genus, which would be true if being were their common genus, or in whatever way it might be common to them. He says that this is Aristotle’s meaning when he says “If the totality of things is a kind of whole.” The second is that beings are related as things having nothing in common. He says that this is Aristotle’s meaning when he says “And if things constitute a whole by reason of succession”; for in either case it follows that substance is prior to the other kinds of being.
2419. But in like manner (1025).
Then he gives a second proof of his thesis. He says that quantity and quality and the like are not beings in an unqualified sense, as will be said below. For being means something having existence, but it is substance alone that subsists. And accidents are called beings, not because they are but rather because by them something is; for example, whiteness is said to be because by it the subject is white. Hence Aristotle says that accidents, as quality and motion, are not called beings in an unqualified sense, but beings of a being.
2420. Nor is it surprising if accidents are called beings even though they are not beings in an unqualified sense, because even privations and negations are called beings in a sense, for example, the not-white and the not-straight. For we say that the not-white is, not because the not-white has being, but because some subject is deprived of whiteness. Accidents and privations have this in common, then, that being is predicated of both by reason of their subject. Yet they differ in this respect that, while a subject has being of some kind by reason of its accidents, it does not have being of any kind by reason of privations, but is deficient in being.
2421. Therefore, since accidents are not beings in an unqualified sense, but only substances are, this science, which considers being as being, is not chiefly concerned with accidents but with substances.
2422. Again, none (1026).
Then he gives a third proof of his thesis that the other kinds of beings cannot exist apart from substance. For accidents can exist only in a subject, and therefore the study of accidents is included in that of substance.
2423. The ancient philosophers (1027).
He gives a fourth proof of his thesis. He says that the ancient philosophers also testify to the fact that the philosopher is concerned with substances, because in seeking the causes of being they looked for the causes only of substance. And some of the moderns also did this, but in a different way; for they did not seek principles, causes and elements in the same way, but differently. For the moderns—the Platonists—claimed that universals are substances to a greater degree than particular things; for they said that genera, which are universals, are principles and causes of substances to a greater degree than particular things. They did this because they investigated things from the viewpoint of dialectics; for they thought that universals, which are separate according to their mode of definition from sensible things, are also separate in reality, and that they are the principles of particular things. But the ancient philosophers, such as Democritus and Empedocles, claimed that the substances and principles of things are particular entities, such as fire and earth, but not this common principle, body.
ARISTOTLE’S TEXT Chapters 1 & 2: 1069a 30-1069b 32
2428. Sensible substance (1029).
2431. If, then, there are (1030).
2437. And one might raise (1034).
2440. This argument holds good against Anaxagoras inasmuch as he claimed that mind needs matter in order to produce some effect. And if he claims that the first principle of things is mind, which produces matter itself, the first principle of the diversity of things will proceed from the order apprehended by the above-mentioned mind, which, inasmuch as it aims to produce different things, establishes different matters having an aptitude for a diversity of things.
ARISTOTLE’S TEXT Chapters 2 & 3: 1069b 32-1070a 30
2442. It should be noted (1036).
2444. Again, it should be (1037).
2446. There are three kinds (1038).
2447. Now in some cases (1039).
2450. Hence efficient causes (1040).
Second, he rejects the argument by which they maintained that there are separate Ideas. For the Platonists said that it was necessary to posit Ideas in order that particular things might be formed in likeness to them. But this is not necessary, because in the realm of lower bodies one finds an adequate cause of the formation of everything that comes to be. For a natural agent produces something like itself. For man begets man; but it is not the universal man who begets a singular man, but the singular man begets a singular man. Hence it is not necessary to hold that there is a separate universal man by reason of which the singular man here receives, or shares in, the form of the species. The same thing is evident of those things which come to be by art, because the medical art is the formal determinant and likeness of health in the mind, as has also been shown above (1040:C 2450).
The Principles of Movable Substances
ARISTOTLE’S TEXT Chapters 4 & 5: 1070a 31-1071b 2
1049. And besides these there is that which as the first of all things imparts motion to all things.
1051. Next, all of these causes are perhaps soul and body, or intellect, appetite and body.
2461. Further, how is it (1045).
2468. And since not only (1047).
2473. And since in the case (1048).
2474. And besides these (1049).
2475. Since some things (1050).
2476. Next, all of these (1051).
2477. Again, there is another sense (1052).
2482. Further, we must note (1053).
2487. Last, he concludes by saying that he has shown the number of principles which sensible substances have and how they are the same or different.
An Eternal Immovable Substance Must Exist
ARISTOTLE’S TEXT Chapter 6: 1071b 3-1071b 22
2495. Further, such substances (1058).
2499. But even if the arguments which prove that motion and time are eternal are not demonstrative and necessarily conclusive, still the things which are proved about the eternity and immateriality of the first substance necessarily follow; for, even if the world were not eternal, it would still have to be brought into being by something that has prior existence. And if this cause were not eternal, it too would have to be produced by something else. But since there cannot be an infinite series, as has been proved in Book II (153:C 301-4), it is necessary to posit an eternal substance whose essence contains no potentiality and is therefore immaterial.
Eternal Motion Requires An Eternal Mover
ARISTOTLE’S TEXT Chapters 6 & 7: 1071b 22-1072a 26
2501. But if this is so (1060).
2504. This is the reason (1061).
2507. That actuality is prior (1063).
2508. Hence Chaos or Night (1064).
2510. Therefore, if something (1065).
2517. Therefore, there is (1066).
2518. Again, if the first mover is eternal and unmoved, it must not be a potential being (because any potential being is naturally fitted to be moved) but an independent substance whose essence is actuality.—This is the conclusion which he drew above (1058:C 2499). But it was necessary to raise this question, which was discussed among the ancients, in order that when it has been solved the course to be followed in reaching a first being whose substance is actuality will be made more evident.
How the First Mover Causes Motion
ARISTOTLE’S TEXT Chapter 7: 1072a 26-1072b 14
2523. And one of the two (1068).
2526. But that which is good (1069).
2529. And it causes motion (1070).
2535. It should also be noted that Aristotle says here that the necessity of the first motion is not absolute necessity but necessity from the end, and the end is the principle which he later calls God inasmuch as things are assimilated to God through motion. Now assimilation to a being that wills and understands (as he shows God to be) is in the line of will and understanding, just as things made by art are assimilated to the artist inasmuch as his will is fulfilled in them. This being so, it follows that the necessity of the first motion is totally subject to the will of God.
The Perfection of the First Substance
ARISTOTLE’S TEXT Chapter 7: 1072b 14-1073a 13
2537. For its operation (1072).
2539. And an intellect (1073).
2544. Life, then, also belongs (1074).
2548. And it has been shown (1076).
2551. It has also been shown (1077).
2552. Last, he concludes that the things discussed above are evidently such as he has established them to be.
ARISTOTLE’S TEXT Chapter 8: 1073a 14-1073b 17
2555. However, we must discuss (1079).
2563. But it is now necessary (1081).
2566. As to the number of planetary motions, let us now state what the mathematicians say about this, so that with this in mind we may conceive some definite number. But as to the other things which have not been stated, we must either investigate these for ourselves or in this matter accept the opinion of those who do investigate the problem. The same thing applies if some view should appear later on in addition to” those which are now stated by men who treat this kind of problem. And since in choosing or rejecting opinions of this kind a person should not be influenced either by a liking or dislike for the one introducing the opinion, but rather by the certainty of truth, he therefore says that we must respect both parties, namely, those whose opinion we follow, and those whose opinion we reject. For both have diligently sought the truth and have aided us in this matter. Yet we must “be persuaded by the more certain,” i.e., we must follow the opinion of those who have attained the truth with greater certitude.
ARISTOTLE’S TEXT Chapter 8: 1073b 17-1074b 14
2578. And Callippus assumed (1083).
2585. Last, he draws his conclusion that the number of spheres is that mentioned.
2586. Hence it is reasonable (1084).
2587. However, if there can be (1085).
2590. But there cannot be (1086).
2593. And it is evident (1087).
2599. Last, he concludes that “the opinion of our forefathers,” i.e., the one received from those who philosophized and after whom philosophy was lost, is evident to us only in this way, i.e., in the form of a myth, as has been stated above (1088:C 2597).
The Dignity of the First Intelligence
ARISTOTLE’S TEXT Chapter 9: 1074b 15-1075a 10
1100. Now whatever does not have matter is indivisible, for example, the human mind.
2601. For if it is not (1090).
2603. Furthermore, whether its substance (1091).
2604. Does it make any difference (1092).
2606. Hence it is evident (1093).
2608. Therefore, if the first mover (1094).
2611. Second, that there is (1095).
2617. And its act of understanding (1096).
2618. Again, if understanding (1097).
2619. But in certain cases (1098).
2621. Yet the difficulty (1099).
He gives the third argument. An act of understanding which is concerned with composite things does not possess its perfection always but attains it over a period of time. This is clear from the fact that it does not attain its good in knowing one part or another, but its greatest good is something else, which is a kind of whole. Hence the truth (which is the good of the intellect), is not found in simple things but in a composite one. Further, simple things are prior to composite things as regards both generation and time, so that whatever does not possess its own good in knowing parts which can be understood separately but in knowing the whole which is constituted of them, attains its good at some particular moment and does not always possess it.—However, the first mover’s act of understanding, which is of himself, is eternal and always in the same state. Therefore the thing understood by the intellect of the first mover is not composite.
God Is the Final Cause of All Things. The Order of the Universe
ARISTOTLE’S TEXT Chapter 10: 1075a 11-1076a 4
1114. Further, no one explains why there is always generation, and what its cause is.
2643. Further, [according to them] (1108).
2644. For other thinkers (1109).
2646. And Empedocles’ doctrine (1111).
2648. Again, Anaxagoras (1112).
2650. But all who speak (1113).
2651. And none of them (ibid.).
2655. And for other thinkers (1116).
2656. Further, if nothing (1117).
2660. Again, as to the way (1121).