Β
BOOK II
THE PRINCIPLES OF NATURAL SCIENCE


Lectio 1 (192 b 8-193 a 8)
WHAT IS NATURE? WHAT THINGS HAVE A NATURE?
WHAT THINGS ARE ‘ACCORDING TO NATURE’?
Chapter 1
Τῶν ὄντων τὰ μέν ἐστι φύσει, τὰ δὲ δι' ἄλλας αἰτίας, φύσει μὲν τά τε ζῷα καὶ τὰ μέρη αὐτῶν καὶ τὰ φυτὰ καὶ τὰ ἁπλᾶ τῶν σωμάτων, οἷον γῆ καὶ πῦρ καὶ ἀὴρ καὶ ὕδωρ (ταῦτα γὰρ εἶναι καὶ τὰ τοιαῦτα φύσει φαμέν), πάντα δὲ ταῦτα φαίνεται διαφέροντα πρὸς τὰ μὴ φύσει συνεστῶτα. τούτων μὲν γὰρ ἕκαστον ἐν ἑαυτῷ ἀρχὴν ἔχει κινήσεως καὶ στάσεως, τὰ μὲν κατὰ τόπον, τὰ δὲ κατ' αὔξησιν καὶ φθίσιν, τὰ δὲ κατ' ἀλλοίωσιν· κλίνη δὲ καὶ ἱμάτιον, καὶ εἴ τι τοιοῦτον ἄλλο γένος ἐστίν, ᾗ μὲν τετύχηκε τῆς κατηγορίας ἑκάστης καὶ καθ' ὅσον ἐστὶν ἀπὸ τέχνης, οὐδεμίαν ὁρμὴν ἔχει μεταβολῆς ἔμφυτον, ᾗ δὲ συμβέβηκεν αὐτοῖς εἶναι λιθίνοις ἢ γηΐνοις ἢ μικτοῖς ἐκ τούτων, ἔχει, καὶ κατὰ τοσοῦτον, Of things that exist, some exist by nature, some from other causes. 'By nature' the animals and their parts exist, and the plants and the simple bodies (earth, fire, air, water)—for we say that these and the like exist 'by nature'. All the things mentioned present a feature in which they differ from things which are not constituted by nature. Each of them has within itself a principle of motion and of stationariness (in respect of place, or of growth and decrease, or by way of alteration). On the other hand, a bed and a coat and anything else of that sort, qua receiving these designations i.e. in so far as they are products of art—have no innate impulse to change. But in so far as they happen to be composed of stone or of earth or of a mixture of the two, they do have such an impulse,
ὡς οὔσης τῆς φύσεως ἀρχῆς τινὸς καὶ αἰτίας τοῦ κινεῖσθαι καὶ ἠρεμεῖν ἐν ᾧ ὑπάρχει πρώτως καθ' αὑτὸ καὶ μὴ κατὰ συμβεβηκός (λέγω δὲ τὸ μὴ κατὰ συμβεβηκός, ὅτι γένοιτ' ἂν αὐτὸς αὑτῷ τις αἴτιος ὑγιείας ὢν ἰατρός· ἀλλ' ὅμως οὐ καθὸ ὑγιάζεται τὴν ἰατρικὴν ἔχει, ἀλλὰ συμβέβηκεν τὸν αὐτὸν ἰατρὸν εἶναι καὶ ὑγιαζόμενον· διὸ καὶ χωρίζεταί ποτ' ἀπ' ἀλλήλων). ὁμοίως δὲ καὶ τῶν ἄλλων ἕκαστον τῶν ποιουμένων· οὐδὲν γὰρ αὐτῶν ἔχει τὴν ἀρχὴν ἐν ἑαυτῷ τῆς ποιήσεως, ἀλλὰ τὰ μὲν ἐν ἄλλοις καὶ ἔξωθεν, οἷον οἰκία καὶ τῶν ἄλλων τῶν χειροκμήτων ἕκαστον, τὰ δ' ἐν αὑτοῖς μὲν ἀλλ' οὐ καθ' αὑτά, ὅσα κατὰ συμβεβηκὸς αἴτια γένοιτ' ἂν αὑτοῖς. φύσις μὲν οὖν ἐστὶ τὸ ῥηθέν· and just to that extent which seems to indicate that nature is a source or cause of being moved and of being at rest in that to which it belongs primarily, in virtue of itself and not in virtue of a concomitant attribute. I say 'not in virtue of a concomitant attribute', because (for instance) a man who is a doctor might cure himself. Nevertheless it is not in so far as he is a patient that he possesses the art of medicine: it merely has happened that the same man is doctor and patient—and that is why these attributes are not always found together. So it is with all other artificial products. None of them has in itself the source of its own production. But while in some cases (for instance houses and the other products of manual labour) that principle is in something else external to the thing, in others those which may cause a change in themselves in virtue of a concomitant attribute—it lies in the things themselves (but not in virtue of what they are). 'Nature' then is what has been stated.
φύσιν δὲ ἔχει ὅσα τοιαύτην ἔχει ἀρχήν. καὶ ἔστιν πάντα ταῦτα οὐσία· ὑποκείμενον γάρ τι, καὶ ἐν ὑποκειμένῳ ἐστὶν ἡ φύσις ἀεί. Things 'have a nature'which have a principle of this kind. Each of them is a substance; for it is a subject, and nature always implies a subject in which it inheres.
κατὰ φύσιν δὲ ταῦτά τε καὶ ὅσα τούτοις ὑπάρχει καθ' αὑτά, οἷον τῷ πυρὶ φέρεσθαι ἄνω· τοῦτο γὰρ φύσις μὲν οὐκ (193a.) ἔστιν οὐδ' ἔχει φύσιν, φύσει δὲ καὶ κατὰ φύσιν ἐστίν. τί μὲν οὖν ἐστιν ἡ φύσις, εἴρηται, καὶ τί τὸ φύσει καὶ κατὰ φύσιν. The term 'according to nature' is applied to all these things and also to the attributes which belong to them in virtue of what they are, for instance the property of fire to be carried upwards—which is not a 'nature' nor 'has a nature' but is 'by nature' or 'according to nature'. What nature is, then, and the meaning of the terms 'by nature' and 'according to nature', has been stated.
ὡς δ' ἔστιν ἡ φύσις, πειρᾶσθαι δεικνύναι γελοῖον· φανερὸν γὰρ ὅτι τοιαῦτα τῶν ὄντων ἐστὶν πολλά. τὸ δὲ δεικνύναι τὰ φανερὰ διὰ τῶν ἀφανῶν οὐ δυναμένου κρίνειν ἐστὶ τὸ δι' αὑτὸ καὶ μὴ δι' αὑτὸ γνώριμον (ὅτι δ' ἐνδέχεται τοῦτο πάσχειν, οὐκ ἄδηλον· συλλογίσαιτο γὰρ ἄν τις ἐκ γενετῆς ὢν τυφλὸς περὶ χρωμάτων), ὥστε ἀνάγκη τοῖς τοιούτοις περὶ τῶν ὀνομάτων εἶναι τὸν λόγον, νοεῖν δὲ μηδέν. That nature exists, it would be absurd to try to prove; for it is obvious that there are many things of this kind, and to prove what is obvious by what is not is the mark of a man who is unable to distinguish what is self-evident from what is not. (This state of mind is clearly possible. A man blind from birth might reason about colours. Presumably therefore such persons must be talking about words without any thought to correspond.)
Postquam philosophus in primo libro determinavit de principiis rerum naturalium, hic determinat de principiis scientiae naturalis. 141. After the Philosopher has treated the principles of natural things in Book I, he here treats the principles of natural science.
Ea autem quae primo oportet cognoscere in aliqua scientia, sunt subiectum ipsius, et medium per quod demonstrat. Now the things which we ought to know first in any science are its subject and the method by which it demonstrates.
Unde hic secundus liber in duas partes dividitur: in prima determinat de quibus sit consideratio scientiae naturalis; in secunda ex quibus causis demonstrat, ibi: determinatis autem his et cetera. scientia naturalis, ibi: quoniam autem determinatum est et cetera. Hence Book II is divided into two parts. First he determines what things belong to the consideration of natural science, and secondly, where he says, ‘Now that we have established...’(194 b 16; L5 #176ff), he points out the causes from which it demonstrates.
Prima dividitur in duas: in prima ostendit quid sit natura; in secunda de quibus considerat The first part is divided into two parts. First he shows what nature is. Secondly, where he says, ‘We have distinguished...’ (193 b 23; L3 #157ff), he determines what things natural science considers.
Prima dividitur in duas: in prima ostendit quid sit natura; in secunda quot modis dicitur, ibi: videtur autem natura, et cetera. The first part is divided into two parts. First he shows what nature is. Secondly the number of ways [in which the name nature is used] is pointed out, where he says, ‘Some identify...’ (193 a 9; L2 #149ff).
Prima dividitur in duas: in prima ostendit quid sit natura; in secunda excludit intentionem quorundam tentantium demonstrare quod natura sit, ibi: quod autem est natura et cetera. The first part is divided into two parts. First he shows what nature is. Secondly, where he says, ‘That nature exists...’ (193 a 2 #148), he refutes the position of those who attempt to demonstrate that nature exists.
Circa primum duo facit: primo notificat naturam; secundo ea quae denominantur a natura, ibi: naturam autem habent et cetera. Concerning the first part he makes two points. First he states what nature is. Secondly, where he says, ‘Things “have a nature” (192 b 33 #146), he designates those things which are called ‘nature’.
Circa primum tria facit: primo investigat definitionem naturae; secundo concludit eam, ibi: est igitur natura etc.; tertio exponit ipsam definitionem, ibi: dico autem non secundum accidens et cetera. Concerning the first part he makes three points. First he inquires into the definition of nature. Secondly he arrives at the definition, where he says, ‘... nature is...’(192 b 22 #145). Thirdly, he explains this definition, where he says, ‘I say...’ (192 b 23 #145).
Dicit ergo primo quod inter omnia entia, quaedam esse dicimus a natura; quaedam vero ab aliis causis, puta ab arte vel a casu. 142. He says, therefore, first that we say that of all beings some are from nature, whereas others are from other causes, for example, from art or from chance.
Dicimus autem esse a natura quaelibet animalia, et partes ipsorum, sicut carnem et ossa, et etiam plantas et corpora simplicia, scilicet elementa, quae non resolvuntur in aliqua corpora priora, ut sunt terra, ignis, aer et aqua: haec enim et omnia similia a natura dicuntur esse. Now we say that the following things are from nature: every sort of animal, and their parts, such as flesh and blood, and also plants and simple bodies, i.e., the elements, such as earth, fire, air and water, which are not resolved into any prior bodies. For these and all things like them are said to be from nature.
Et differunt haec omnia ab his quae non sunt a natura, quia omnia huiusmodi videntur habere in se principium alicuius motus et status; quaedam quidem secundum locum, sicut gravia et levia, et etiam corpora caelestia; quaedam vero secundum augmentum et decrementum, ut animalia et plantae; quaedam vero secundum alterationem, ut corpora simplicia et omnia quae componuntur ex eis. All of these things differ from the things which are not from nature because all things of this sort seem to have in themselves a principle of motion and rest; some according to place, such as the heavy and the light, and also the celestial bodies, some according to increase and decrease, such as the animals and plants, and some according to alteration, such as the simple bodies and everything which is composed of them.
Sed ea quae non sunt a natura, sicut lectus et indumentum et similia, quae accipiunt huiusmodi praedicationem secundum quod sunt ab arte, nullius mutationis principium habent in seipsis nisi per accidens, inquantum scilicet materia et substantia corporum artificiatorum sunt res naturales. Sic igitur inquantum artificialibus accidit esse ferrea vel lapidea, habent aliquod principium motus in seipsis, sed non inquantum sunt artificiata: cultellus enim habet in se principium motus deorsum, non inquantum est cultellus, sed inquantum est ferreus. But things which are not from nature, such as a bed and clothing and like things, which are spoken of in this way because they are from art, have in themselves no principle of mutation, except per accidents, insofar as the matter and substance of artificial bodies are natural things. Thus insofar as artificial things happen to be iron or stone, they have a principle of motion in them, but not insofar as they are artifacts. For a knife has in itself a principle of downward motion, not insofar as it is a knife, but insofar as it is iron.
Sed videtur hoc non esse verum, quod secundum quamlibet mutationem rerum naturalium, principium motus sit in eo quod movetur. In alteratione enim et generatione simplicium corporum, totum principium motus videtur esse ab extrinseco agente: puta cum aqua calefit, vel aer in ignem convertitur, principium mutationis est ab exteriori agente. 143. But it does not seem to be true that in every change of natural things a principle of motion is- in that which is moved. For in the alteration and the generation of simple bodies, the whole principle of motion seems to be from an external agent. For example, when water is heated, or air is converted into fire, the principle of the change is from an external agent.
Dicunt ergo quidam quod etiam in huiusmodi mutationibus principium activum motus est in eo quod movetur; non quidem perfectum, sed imperfectum, quod coadiuvat actionem exterioris agentis. Dicunt enim quod in materia est quaedam inchoatio formae, quam dicunt esse privationem, quae est tertium principium naturae; et ab hoc principio intrinseco generationes et alterationes corporum simplicium naturales dicuntur. Therefore, some say that even in changes of this sort an active principle of motion is in that which is moved, not perfectly, but imperfectly, which principle helps the action of the external agent. For they say that in matter there is a certain inchoateness of form, which they say is privation, the third principle of nature. And the generations and alterations of simple bodies are said to be from this intrinsic principle.
Sed hoc non potest esse: quia, cum nihil agat nisi secundum quod est in actu, praedicta inchoatio formae, cum non sit actus, sed aptitudo quaedam ad actum, non potest esse principium activum. Et praeterea, etiam si esset forma completa, non ageret in suum subiectum alterando ipsum: quia forma non agit, sed compositum; quod non potest seipsum alterare, nisi sint in eo duae partes, quarum una sit alterans et alia alterata. But this cannot be. Since a thing acts only insofar as it is in act, the aforesaid inchoate state of form, since it is not act, but a certain disposition for act, cannot be an active principle. And furthermore, even if it were a complete form, it would not act on its own subject by ‘changing it. For the form does not act, rather the composite acts. And the composite cannot alter itself unless there are two parts in it, one of which alters, the other of which is altered.
Et ideo dicendum est quod in rebus naturalibus eo modo est principium motus, quo eis motus convenit. Quibus ergo convenit movere, est in eis principium activum motus; quibus autem competit moveri, est in eis principium passivum, quod est materia. Quod quidem principium, inquantum habet potentiam naturalem ad talem formam et motum, facit esse motum naturalem. Et propter hoc factiones rerum artificialium non sunt naturales: quia licet principium materiale sit in eo quod fit, non tamen habet potentiam naturalem ad talem formam. 144. And so it must be said that a principle of motion is in natural things in the way in which motion belongs to them. Therefore in those things to which it belongs to move, there is an active principle of motion. Whereas in those things to which it belongs to be moved, there is a passive principle, which is matter. And this principle, insofar as it has a natural potency for such a form and motion, makes the motion to be natural. And for this reason the production of artificial things is not natural. For even though the material principle is in that which comes to be, it does not have a natural potency for such a form.
Et sic etiam motus localis corporum caelestium est naturalis, licet sit a motore separato, inquantum in ipso corpore caeli est potentia naturalis ad talem motum. So also the local motion of the celestial bodies is natural, even though it is from a separated mover, inasmuch as there is in the celestial body itself a natural potency for such a motion.
In corporibus vero gravibus et levibus est principium formale sui motus (sed huiusmodi principium formale non potest dici potentia activa, ad quam pertinet motus iste, sed comprehenditur sub potentia passiva: gravitas enim in terra non est principium ut moveat, sed magis ut moveatur): quia sicut alia accidentia consequuntur formam substantialem, ita et locus, et per consequens moveri ad locum: non tamen ita quod forma naturalis sit motor, sed motor est generans, quod dat talem formam, ad quam talis motus consequitur. However in heavy and light bodies there is a formal principle of motion. (But a formal principle of this sort cannot be called the active potency to which this motion pertains. Rather it is understood as a passive potency. For heaviness in earth is not a principle for moving, but rather for being moved.) For just as the other accidents are consequent upon substantial form, so also is place, and thus also ‘to be moved to place’. However the natural form is not the mover. Rather the mover is that which generates and gives such and such a form upon which such a motion follows.
Deinde cum dicit: est igitur natura etc., concludit ex praemissis definitionem naturae hoc modo. 145. Next where he says, ‘... nature is...’ (192 b 22), he concludes from the above the definition of nature in the following manner.
Naturalia differunt a non naturalibus inquantum habent naturam; sed non differunt a non naturalibus nisi inquantum habent principium motus in seipsis; ergo natura nihil aliud est quam principium motus et quietis in eo in quo est primo et per se et non secundum accidens. Natural things differ from the non-natural insofar as they have a nature. But they differ from the non-natural only insofar as they have in themselves a principle of motion. Therefore, nature is nothing other than a principle of motion and rest in that in which it is primarily and per se and not per accidens.
Ponitur autem in definitione naturae principium, quasi genus, et non aliquid absolutum, quia nomen naturae importat habitudinem principii. Quia enim nasci dicuntur ea quae generantur coniuncta generanti, ut patet in plantis et animalibus, ideo principium generationis vel motus natura nominatur. Unde deridendi sunt qui volentes definitionem Aristotelis corrigere, naturam per aliquid absolutum definire conati sunt, dicentes quod natura est vis insita rebus, vel aliquid huiusmodi. Now ‘principle’ is placed in the definition of nature as its genus, and not as something absolute, for the name ‘nature’ involves a relation to a principle. For those things are said to be born which are generated after having been joined to a generator, as is clear in plants and animals, thus the principle of generation or motion is called nature. Hence they are to be laughed at who, wishing to correct the definition of Aristotle, tried to define nature by something absolute, saying that nature is a power seated in things or something of this sort.
Dicitur autem principium et causa, ad designandum quod non omnium motuum natura est eodem modo principium in eo quod movetur, sed diversimode, ut dictum est. Moreover, nature is called a principle and cause in order to point out that in that which is moved nature is not a principle of all motions in the same way, but in different ways, as was said above [#144].
Dicit autem movendi et quiescendi, quia ea quae naturaliter moventur ad locum, similiter vel magis naturaliter in loco quiescunt: propter hoc enim ignis naturaliter movetur sursum, quia naturaliter ibi est, et propter quod unumquodque et illud magis. Non tamen intelligendum est quod in quolibet quod movetur naturaliter, natura sit etiam principium quiescendi; quia corpus caeleste naturaliter quidem movetur, sed non naturaliter quiescit: sed hoc pro tanto dicitur, quia non solum motus, sed etiam quietis principium est. Moreover, he says that nature is a principle ‘of motion and rest’. For those things which are naturally moved to a place, also or even more naturally rest in that place. Because of this, fire is naturally moved upward, since it is natural for it to be there. And for the same reason everything can be said to be moved naturally and to rest naturally in its place. This, however, must not be understood to mean that in everything which is moved naturally nature is also a principle of coming to rest. For a heavenly body is indeed moved naturally, but it does not naturally come to rest. But on the whole it can be said that nature is not only a principle of motion but also of rest.
Dicit autem in quo est, ad differentiam artificialium, in quibus non est motus nisi per accidens. Further he says ‘in which it is’ in order to differentiate nature from artificial things in which there is motion only per accidens.
Addit autem primum, quia natura, etsi sit principium motus compositorum, non tamen primo. Unde quod animal movetur deorsum, non est ex natura animalis inquantum est animal, sed ex natura dominantis elementi. Then he adds ‘Primarily’ because even though nature is a principle of the motion of composite things, nevertheless it is not such primarily. Hence that an animal is moved downwards is not because of the nature of animal insofar as it is animal, but because of the nature of the dominant element.
Quare autem dicat per se et non secundum accidens, exponit consequenter cum dicit: dico autem non secundum accidens. He explains why he says ‘ per se and not per accidens ’ where he says, ‘I say “not in virtue of...”’ (192 b 24).
Contingit enim aliquando quod aliquis medicus est sibi ipsi causa sanitatis; et sic principium suae sanationis est in eo, sed per accidens: unde principium sanationis in eo non est natura. Non enim secundum quod sanatur habet medicinam, sed secundum quod est medicus; accidit autem eundem esse medicum et sanari; sanatur enim secundum quod est infirmus. Et ideo, quia per accidens coniunguntur, aliquando per accidens dividuntur: contingit enim alium esse medicum sanantem et alium infirmum qui sanatur. Sed principium motus naturalis est in corpore naturali quod movetur, inquantum movetur: inquantum enim ignis habet levitatem, fertur sursum. Nec dividuntur ad invicem, ut aliud sit corpus quod movetur sursum et aliud leve, sed semper unum et idem. Et sicuti est de medico sanante, ita est de omnibus artificialibus. Nullum enim eorum habet in seipso suae factionis principium: sed quaedam eorum fiunt ab extrinseco, ut domus et alia quae manu inciduntur; quaedam autem fiunt a principio intrinseco, sed per accidens, ut dictum est. Et sic dictum est quid sit natura. It sometimes happens that a doctor is the cause of his own health, and so the principle of his own coming to health is in him, but per accidens. Hence nature is not the principle of his coming to health. For it is not insofar as he is cured that he has the art of medicine, but insofar as he is a doctor. Hence the same being happens to be a doctor and to be cured, and he is cured insofar as he is sick. And so because these things are joined per accidens, they are also at times separated per accidens. For it is one thing to be a doctor who cures, and another thing to be a sick person who is cured. But the principle of a natural motion is in the natural body which is moved insofar as it is moved. For insofar as fire has lightness, it is carried upward. And these two things are not divided from each other so that the lightness is different than the body which is moved upward. Rather they are always one and the same. And all artificial things are like the doctor who cures. For none of them has in itself the principle of its own making. Rather some of them come to be from something outside, as a house and other things which are carved by hand, while others come to be through an intrinsic principle, but per accidens, as was said [#142]. And so it has been stated what nature is.
Deinde cum dicit: naturam autem habent etc., definit ea quae a natura denominantur. 146. Next where he says, ‘Things “have a nature”...’ (192 b 33), he defines those things which are given the name ‘nature’.
Et dicit quod habentia naturam sunt illa quae habent in seipsis principium sui motus. Et talia sunt omnia subiecta naturae: quia natura est subiectum, secundum quod natura dicitur materia; et est in subiecto, secundum quod natura dicitur forma. He says that those things which have in themselves a principle of their motion have a nature. And such are all subjects of nature. For nature is a subject insofar as it is called matter, and nature is in a subject insofar as it is called form.
Deinde cum dicit: secundum naturam autem sunt etc., exponit quid sit secundum naturam. 147. Next where he says, ‘The term “according to nature” (192 b 35), he explains what is ‘according to nature’.
Et dicit quod secundum naturam esse dicuntur tam subiecta, quorum esse est a natura, quam etiam accidentia quae in eis insunt causata ab huiusmodi principio; sicut ferri sursum non est ipsa natura, neque habens naturam, sed est causatum a natura. He says that ‘to be according to nature’ is said both of subjects whose existence is from nature and also of the accidents which are in them and caused by such a principle. Thus to be carried upward is not a nature itself, nor does it have nature, but it is caused by nature.
Et sic dictum est quid sit natura, et quid sit illud quod habet naturam, et quid sit secundum naturam. And thus it has been stated what nature is, and what it is that has nature, and what is ‘according to nature’.
Deinde cum dicit: quod autem est natura etc., excludit praesumptionem quorundam volentium demonstrare quod natura sit. 148. Next where he says, ‘That nature exists...’ (193 a 2), he denies the presumptuous position of those who wish to demonstrate that nature exists.
Et dicit quod ridiculum est quod aliquis tentet demonstrare quod natura sit, cum manifestum sit secundum sensum quod multa sunt a natura, quae habent principium sui motus in se. Velle autem demonstrare manifestum per non manifestum, est hominis qui non potest iudicare quid est notum propter se, et quid non est notum propter se: quia dum vult demonstrare id quod est notum propter se, utitur eo quasi non propter se noto. Et quod hoc contingat aliquibus, manifestum est. Aliquis enim caecus natus aliquando syllogizat de coloribus: cui tamen non est per se notum id quo utitur ut principio, quia non habet intellectum rei, sed utitur solum nominibus; eo quod cognitio nostra ortum habet a sensu, et cui deficit unus sensus, deficit una scientia. Unde caeci nati, qui nunquam senserunt colorem, non possunt aliquid de coloribus intelligere; et sic utuntur non notis quasi notis. Et e converso accidit his qui volunt demonstrare naturam esse: quia utuntur notis ut non notis. Naturam autem esse, est per se notum, inquantum naturalia sunt manifesta sensui. Sed quid sit uniuscuiusque rei natura, vel quod principium motus, hoc non est manifestum. He says that it is ridiculous for anyone to attempt to demonstrate that nature exists. For it is manifest to the senses that many things are from nature, which have in themselves the principle of their own motion. To wish, moreover, to demonstrate the obvious by what is not obvious is the mark of a man who cannot judge what is known in itself and what is not known in itself. For when he wishes to demonstrate that which is known in itself, he uses that which is known in itself as if it were not known in itself. And it is clear that some people do this. A man who is born blind may sometimes reason about colours. But that which he uses as a principle is not known to him per se, because he has no understanding of the thing. Rather he only uses names. For our knowledge has its origin from the senses, and he who lacks one sense, lacks one science. Hence those who are born blind, and who never sense colour, cannot understand any thing about colour. And so they use the unknown as if it were known. And the converse applies to those who wish to demonstrate that nature exists. For they use the known as if it were not known. The existence of nature is known per se, insofar as natural things are manifest to the senses. But what the nature of each thing is, or what the principle of its motion is, is not manifest.
Unde patet per hoc quod irrationabiliter Avicenna conatus est improbare Aristotelis dictum, volens quod naturam esse possit demonstrari, sed non a naturali, quia nulla scientia probat sua principia. Sed ignorantia principiorum moventium non impedit quin naturam esse sit per se notum, ut dictum est. Hence it is clear from this that Avicenna, who wished that it were possible to prove the existence of nature, unreasonably attempted to disprove what Aristotle has said. However Avicenna did not wish to prove this from natural things, for no science proves its own principles. But ignorance of moving principles does not mean that the existence of nature is not known per se, as was said.

Lectio 2 (193.a 9-b 21)
NATURE IS BOTH MATTER AND FORM, BUT PRIMARILY FORM
Chapter 1 cont.
δοκεῖ δ' ἡ φύσις καὶ ἡ οὐσία τῶν φύσει ὄντων ἐνίοις εἶναι τὸ πρῶτον ἐνυπάρχον ἑκάστῳ, ἀρρύθμιστον <�ὂν>καθ' ἑαυτό, οἷον κλίνης φύσις τὸ ξύλον, ἀνδριάντος δ' ὁ χαλκός. σημεῖον δέ φησιν Ἀντιφῶν ὅτι, εἴ τις κατορύξειε κλίνην καὶ λάβοι δύναμιν ἡ σηπεδὼν ὥστε ἀνεῖναι βλαστόν, οὐκ ἂν γενέσθαι κλίνην ἀλλὰ ξύλον, ὡς τὸ μὲν κατὰ συμβεβηκὸς ὑπάρχον, τὴν κατὰ νόμον διάθεσιν καὶ τὴν τέχνην, τὴν δ' οὐσίαν οὖσαν ἐκείνην ἣ καὶ διαμένει ταῦτα πάσχουσα συνεχῶς. εἰ δὲ καὶ τούτων ἕκαστον πρὸς ἕτερόν τι ταὐτὸ τοῦτο πέπονθεν (οἷον ὁ μὲν χαλκὸς καὶ ὁ χρυσὸς πρὸς ὕδωρ, τὰ δ' ὀστᾶ καὶ ξύλα πρὸς γῆν, ὁμοίως δὲ καὶ τῶν ἄλλων ὁτιοῦν), ἐκεῖνο τὴν φύσιν εἶναι καὶ τὴν οὐσίαν αὐτῶν. διόπερ οἱ μὲν πῦρ, οἱ δὲ γῆν, οἱ δ' ἀέρα φασίν, οἱ δὲ ὕδωρ, οἱ δ' ἔνια τούτων, οἱ δὲ πάντα ταῦτα τὴν φύσιν εἶναι τὴν τῶν ὄντων. ὃ γάρ τις αὐτῶν ὑπέλαβε τοιοῦτον, εἴτε ἓν εἴτε πλείω, τοῦτο καὶ τοσαῦτά φησιν εἶναι τὴν ἅπασαν οὐσίαν, τὰ δὲ ἄλλα πάντα πάθη τούτων καὶ ἕξεις καὶ διαθέσεις, καὶ τούτων μὲν ὁτιοῦν ἀΐδιον (οὐ γὰρ εἶναι μεταβολὴν αὐτοῖς ἐξ αὑτῶν), τὰ δ' ἄλλα γίγνεσθαι καὶ φθείρεσθαι ἀπειράκις. ἕνα μὲν οὖν τρόπον οὕτως ἡ φύσις λέγεται, ἡ πρώτη ἑκάστῳ ὑποκειμένη ὕλη τῶν ἐχόντων ἐν αὑτοῖς ἀρχὴν κινήσεως καὶ μεταβολῆς, Some identify the nature or substance of a natural object with that immediate constituent of it which taken by itself is without arrangement, e.g. the wood is the 'nature' of the bed, and the bronze the 'nature' of the statue. As an indication of this Antiphon points out that if you planted a bed and the rotting wood acquired the power of sending up a shoot, it would not be a bed that would come up, but wood—which shows that the arrangement in accordance with the rules of the art is merely an incidental attribute, whereas the real nature is the other, which, further, persists continuously through the process of making. But if the material of each of these objects has itself the same relation to something else, say bronze (or gold) to water, bones (or wood) to earth and so on, that (they say) would be their nature and essence. Consequently some assert earth, others fire or air or water or some or all of these, to be the nature of the things that are. For whatever any one of them supposed to have this character—whether one thing or more than one thing—this or these he declared to be the whole of substance, all else being its affections, states, or dispositions. Every such thing they held to be eternal (for it could not pass into anything else), but other things to come into being and cease to be times without number. This then is one account of 'nature', namely that it is the immediate material substratum of things which have in themselves a principle of motion or change.
ἄλλον δὲ τρόπον ἡ μορφὴ καὶ τὸ εἶδος τὸ κατὰ τὸν λόγον. ὥσπερ γὰρ τέχνη λέγεται τὸ κατὰ τέχνην καὶ τὸ τεχνικόν, οὕτω καὶ φύσις τὸ κατὰ φύσιν [λέγεται] καὶ τὸ φυσικόν, οὔτε δὲ ἐκεῖ πω φαῖμεν ἂν ἔχειν κατὰ τὴν τέχνην οὐδέν, εἰ δυνάμει μόνον ἐστὶ κλίνη, μή πω δ' ἔχει τὸ εἶδος τῆς κλίνης, οὐδ' εἶναι τέχνην, οὔτ' ἐν τοῖς φύσει συνισταμένοις· τὸ γὰρ δυνάμει σὰρξ ἢ ὀστοῦν οὔτ' (193b.) ἔχει πω τὴν ἑαυτοῦ φύσιν, πρὶν ἂν λάβῃ τὸ εἶδος τὸ κατὰ τὸν λόγον, ᾧ ὁριζόμενοι λέγομεν τί ἐστι σὰρξ ἢ ὀστοῦν, οὔτε φύσει ἐστίν. ὥστε ἄλλον τρόπον ἡ φύσις ἂν εἴη τῶν ἐχόντων ἐν αὑτοῖς κινήσεως ἀρχὴν ἡ μορφὴ καὶ τὸ εἶδος, οὐ χωριστὸν ὂν ἀλλ' ἢ κατὰ τὸν λόγον. (τὸ δ' ἐκ τούτων φύσις μὲν οὐκ ἔστιν, φύσει δέ, οἷον ἄνθρωπος.) καὶ μᾶλλον αὕτη φύσις τῆς ὕλης· ἕκαστον γὰρ τότε λέγεται ὅταν ἐντελεχείᾳ ᾖ, μᾶλλον ἢ ὅταν δυνάμει. Another account is that 'nature' is the shape or form which is specified in the definition of the thing. For the word 'nature' is applied to what is according to nature and the natural in the same way as 'art' is applied to what is artistic or a work of art. We should not say in the latter case that there is anything artistic about a thing, if it is a bed only potentially, not yet having the form of a bed; nor should we call it a work of art. The same is true of natural compounds. What is potentially flesh or bone has not yet its own 'nature', and does not exist until it receives the form specified in the definition, which we name in defining what flesh or bone is. Thus in the second sense of 'nature' it would be the shape or form (not separable except in statement) of things which have in themselves a source of motion. (The combination of the two, e.g. man, is not 'nature' but 'by nature' or 'natural'.) The form indeed is 'nature' rather than the matter; for a thing is more properly said to be what it is when it has attained to fulfilment than when it exists potentially.
ἔτι γίγνεται ἄνθρωπος ἐξ ἀνθρώπου, ἀλλ' οὐ κλίνη ἐκ κλίνης· διὸ καί φασιν οὐ τὸ σχῆμα εἶναι τὴν φύσιν ἀλλὰ τὸ ξύλον, ὅτι γένοιτ' ἄν, εἰ βλαστάνοι, οὐ κλίνη ἀλλὰ ξύλον. εἰ δ' ἄρα τοῦτο φύσις, καὶ ἡ μορφὴ φύσις· γίγνεται γὰρ ἐξ ἀνθρώπου ἄνθρωπος. Again man is born from man, but not bed from bed. That is why people say that the figure is not the nature of a bed, but the wood is—if the bed sprouted not a bed but wood would come up. But even if the figure is art, then on the same principle the shape of man is his nature. For man is born from man.
ἔτι δ' ἡ φύσις ἡ λεγομένη ὡς γένεσις ὁδός ἐστιν εἰς φύσιν. οὐ γὰρ ὥσπερ ἡ ἰάτρευσις λέγεται οὐκ εἰς ἰατρικὴν ὁδὸς ἀλλ' εἰς ὑγίειαν· ἀνάγκη μὲν γὰρ ἀπὸ ἰατρικῆς οὐκ εἰς ἰατρικὴν εἶναι τὴν ἰάτρευσιν, οὐχ οὕτω δ' ἡ φύσις ἔχει πρὸς τὴν φύσιν, ἀλλὰ τὸ φυόμενον ἐκ τινὸς εἰς τὶ ἔρχεται ᾗ φύεται. τί οὖν φύεται; οὐχὶ ἐξ οὗ, ἀλλ' εἰς ὅ. ἡ ἄρα μορφὴ φύσις. We also speak of a thing's nature as being exhibited in the process of growth by which its nature is attained. The 'nature' in this sense is not like 'doctoring', which leads not to the art of doctoring but to health. Doctoring must start from the art, not lead to it. But it is not in this way that nature (in the one sense) is related to nature (in the other). What grows qua growing grows from something into something. Into what then does it grow? Not into that from which it arose but into that to which it tends. The shape then is nature.
ἡ δὲ μορφὴ καὶ ἡ φύσις διχῶς λέγεται· καὶ γὰρ ἡ στέρησις εἶδός πώς ἐστιν. εἰ δ' ἔστιν στέρησις καὶ ἐναντίον τι περὶ τὴν ἁπλῆν γένεσιν ἢ μὴ ἔστιν, ὕστερον ἐπισκεπτέον. 'Shape' and 'nature', it should be added, are in two senses. For the privation too is in a way form. But whether in unqualified coming to be there is privation, i.e. a contrary to what comes to be, we must consider later.
Postquam philosophus ostendit quid est natura, hic ostendit quot modis natura dicitur. Et primo ostendit quod natura dicitur de materia; secundo quod dicitur de forma, ibi: alio autem modo et cetera. 149. Having shown what nature is, the Philosopher here points out the number of ways in which the name ‘nature’ is used. He shows first that nature is predicated of matter, secondly that it is predicated of form, where he says, ‘Another account...’ (193 a 30 #151).
Circa primum, sciendum est quod antiqui philosophi naturales, non valentes usque ad primam materiam pervenire, ut supra dictum est, aliquod corpus sensibile primam materiam omnium rerum ponebant, ut ignem vel aerem vel aquam: et sic sequebatur quod omnes formae advenirent materiae tanquam in actu existenti, ut contingit in artificialibus; nam forma cultelli advenit ferro iam existenti in actu. Et ideo similem opinionem accipiebant de formis naturalibus, sicut de formis artificialibus. Concerning the first point we must note that the ancient natural philosophers, being unable to arrive at primary matter, as was said above [I, L12 #108], held that some sensible body, such as fire or air or water, is the first matter of all things. And so it followed that all forms come to matter as to something existing in act, as happens in artificial things. For the form of knife comes to iron already existing in act. And so they adopted an opinion about natural forms similar to that which is true of artificial forms.
Dicit ergo primo quod quibusdam videtur quod hoc sit substantia et natura rerum naturalium, quod primo inest unicuique, quod secundum se consideratum est informe: ut si dicamus quod natura lecti est lignum, et natura statuae est aes; nam lignum est in lecto, et secundum se consideratum non est formatum. Et huius signum dicebat Antiphon esse hoc, quod si aliquis proiiciat lectum ad terram, et ligna putrescendo accipiant potentiam ut aliquid ex eis germinet, illud quod generatur non erit lectus, sed lignum. Et quia substantia est quae permanet, et naturae est sibi simile generare, concludebat quod omnis dispositio quae est secundum quamcumque legem rationis vel artem, sit accidens: et illud quod permanet sit substantia, quae continue patitur huiusmodi dispositionum immutationem. He says, therefore, first that it seems to some that that which is primarily in each thing and which considered in itself is unformed is the substance and nature of natural things, as if we would say that the nature of a bed is wood, and the nature of a statue is bronze. For wood is in the bed and is, when considered in itself, not formed. And Antiphon said that the following is a sign of this: if one should bury a bed in the earth and if the wood by rotting should acquire the potency to germinate something, that which is generated will not be a bed, but wood. Now since the substance is that which remains permanent, and since it belongs to nature to generate what is like itself, he concluded that every disposition in respect to any law of reason [ratio] or art is an accident. And that which remains permanent is substance, which continually undergoes change of dispositions of this sort.
Supposito igitur quod rerum artificialium formae sint accidentia, et materia sit substantia, assumebat aliam propositionem, quod sicut se habent lectus et statua ad aes et lignum, ita et quodlibet horum se habet ad aliquid aliud quod est materia ipsorum; ut aes et aurum ad aquam (quia omnium liquefactibilium materia videtur esse aqua), et ossa et ligna ad terram, et similiter est de quolibet aliorum naturalium. Unde concludebat quod illa materialia subsistentia formis naturalibus, sint natura et substantia eorum. Et propter hoc quidam dixerunt terram esse naturam et substantiam omnium rerum, scilicet primi poetae theologizantes; posteriores vero philosophi vel ignem vel aerem vel aquam, vel quaedam horum, vel omnia haec, ut ex superioribus patet. Quia tot de numero eorum dicebant esse substantiam omnium rerum, quot accipiebant esse principia materialia; et omnia alia dicebant esse accidentia horum, idest materialium principiorum, vel per modum passionis vel per modum habitus vel per modum dispositionis, vel cuiuslibet alterius quod reducatur ad genus accidentis. Having supposed, therefore, that the forms of artificial things are accidents, and that matter is substance, Antiphon assumed the other proposition, namely, that just as the bed and statue are related to bronze and wood, so also each natural thing is related to some other thing which is its matter. Thus bronze and gold are related to water (because the matter of all liquifiable things seems to be water), and bone and wood are related to earth, and it is the same with all other natural things. Hence he concluded that the material things which subsist under natural forms are their nature and substance. And because of this some have said that earth is the nature and substance of all things, for example, the first theological poets; whereas the later philosophers chose fire or air or water, or some of these or all of them, as is clear from what was said above [I, L2 #13; L8 #54]. For they said that there are as many u stances of things as there are material principles. And they said that all other things are accidents of these material principles, either as passions, or as habits, or as dispositions, or as anything else which is reduced to the genus of accident.
Et haec est una differentia quam ponebant inter principia materialia et formalia, quia dicebant ea differre secundum substantiam et accidens. Thus one difference which they posited between material and formal principles is that they said that they differed as substance and accident.
Alia autem differentia est, quia dicebant ea differre secundum perpetuum et corruptibile. Nam quodcumque praemissorum corporum simplicium ponebant esse materiale principium, dicebant illud esse perpetuum: non enim dicebant quod transmutarentur invicem. Sed omnia alia dicebant fieri et corrumpi infinities: ut puta, si aqua sit principium materiale, dicebant aquam nunquam corrumpi, sed manere eam in omnibus sicut substantiam eorum; sed aes et aurum et alia huiusmodi dicebant corrumpi et generari infinities. There is, however, another difference, for they also said that these principles differ as the permanent and the corruptible. Since they held that each of the aforementioned simple bodies is a material principle, they said it was permanent, for they did not say that they were changed into each other. But they said that all other things come to be and are corrupted infinitely. For example, if water is the material principle, they said that water is never corrupted, but remains water in all things as their substance. But they said that bronze and gold and other things of this sort are corrupted and generated infinitely.
Haec autem positio quantum ad aliquid vera est, et quantum ad aliquid falsa. Quantum enim ad hoc quod materia sit substantia et natura rerum naturalium, vera est; materia enim intrat constitutionem substantiae cuiuslibet rei naturalis: sed quantum ad hoc quod dicebant omnes formas esse accidentia, falsa est. 150. This position is in part true and in part false. With reference to the point that matter is the substance and the nature of natural things, it is true. For matter enters into the constitution of the substance of each natural thing. But insofar as they said that all forms are accidents, this position is false.
Unde ex hac opinione et ratione eius concludit id quod verum est, scilicet quod natura uno modo dicitur materia quae subiicitur unicuique rei naturali habenti in se principium motus vel cuiuscumque mutationis: nam motus est species mutationis, ut in quinto huius dicetur. Whence from this opinion and from his argument, Aristotle concludes to that which is true, namely, that nature in one way is called matter, which underlies each natural thing which has in itself a principle of motion or of some sort of mutation. For motion is a species of mutation, as will be said in Book V [L2 #649ff].
Deinde cum dicit: alio autem modo etc., ostendit quod natura dicitur de forma. 151. Next where he says, ‘Another account...’ (193 a 30), he shows that the form is also called nature.
Et circa hoc duo facit: primo ostendit propositum, scilicet quod forma sit natura; secundo ostendit formarum diversitatem, ibi: sed forma et natura et cetera. Concerning this he makes two points. First he states his position, i.e., that form is nature. Secondly, where he says, ‘Shape and nature...’ (193 b 19 #156), he explains the diversity of forms.
Primum autem ostendit tribus rationibus. Dicit ergo primo quod alio modo dicitur natura forma et species, quae est secundum rationem, idest ex qua ratio rei constituitur: et hoc probat tali ratione. He explains the first point with three arguments. He says, therefore, first that nature is used in another way to refer to the form and species, from which the nature [ ratio ] of the thing is constituted. He proves this by the following argument.
Sicuti enim illud est ars, quod competit alicui inquantum est secundum artem et artificiosum; ita illud est natura, quod competit alicui inquantum est secundum naturam et naturale. Sed illud quod est in potentia tantum ad hoc quod sit artificiosum, non dicimus habere aliquid artis, quia nondum habet speciem lecti: ergo in rebus naturalibus id quod est potentia caro et os, non habet naturam carnis et ossis antequam accipiat formam, secundum quam sumitur ratio definitiva rei (per quam scilicet scimus quid est caro vel os); nec adhuc est natura in ipso antequam habeat formam. Ergo natura rerum naturalium habentium in se principium motus, alio modo etiam forma est: quae licet non separetur a materia secundum rem, tamen differt ab ea ratione. Sicut enim aes et infiguratum, quamvis sint unum subiecto, tamen ratione differunt, ita materia et forma. Just as art belongs to a thing insofar as it is according to art and the artistic, so also nature belongs to a thing insofar as it is according to nature and the natural. But we do not say that that which is only in potency to that which is artistic has anything of art, because it does not yet have the species [e.g.] of a bed. Therefore in natural things that which is potentially flesh and bone does not have the nature of flesh and bone before it takes on the form in respect to which the definitive nature [ ratio ] of the thing is established (i.e. that through which we know what flesh and bone are). The nature is not yet in it before it has the form. Therefore the nature of natural things which have in themselves a principle of motion is in another way the form. And this form, although it is not separated from the matter in the thing, still differs from the matter by reason [ ratio ]. For as bronze and the shapeless, although one in subject, are different in reason [ ratio ], so also are matter and form.
Et hoc pro tanto dicit, quia nisi forma esset aliud secundum rationem a materia, non esset alius et alius modus quo materia dicitur natura, et quo forma dicitur natura. He says this because unless form were other than matter according to reason [ ratio ], the ways in which matter is called nature and form is called nature would not be different.
Posset autem aliquis credere quod quia materia dicitur natura et etiam forma, quod compositum possit dici natura; quia substantia dicitur de forma et materia et de composito. 152. Moreover one might believe that since both matter and form are called nature then the composite could also be called nature. For substance is predicated of form and of matter and of the composite.
Sed hoc excludit dicens quod compositum ex materia et forma, ut homo, non est ipsa natura, sed est aliquid a natura; quia natura habet rationem principii, compositum autem habet rationem principiati. But he denies this, saying that the composite of matter and form, such as a man, is not the nature itself, but is some thing from nature. For nature [ natura ] has the nature [ ratio ] of a principle, but the composite has the nature [ ratio ] of ‘being from a principle’.
Ulterius autem ex ratione praemissa procedit ad ostendendum quod forma sit magis natura quam materia; quia unumquodque magis dicitur secundum quod est in actu, quam secundum quod est in potentia. Unde forma, secundum quam aliquid est naturale in actu, est magis natura quam materia, secundum quam est aliquid naturale in potentia. 153. From the foregoing argument he proceeds further to show that form is nature more than matter. For a thing is said to be greater insofar as it is in act rather than insofar as it is in potency. Whence form, according to which a thing is natural in act, is nature more than matter, according to which a thing is something natural in potency.
Secundam rationem ponit ibi: amplius fit ex homine et cetera. Et dicit quod licet non fiat lectulus ex lectulo, ut Antiphon dicebat, fit tamen homo ex homine. Unde verum est quod dicunt, quod forma lecti non est natura, sed lignum; quoniam si lignum germinet, non fiet lectus, sed lignum. Sicut igitur haec forma quae non redit per germinationem, non est natura sed ars: ita forma quae redit per generationem, est natura. Sed forma rei naturalis redit per generationem, fit enim ex homine homo: ergo forma rei naturalis est natura. 154. He gives the second argument where he says, ‘Again man is...’ (193 b 8). He says that although a bed does not come to be from a bed, as Antiphon said, man does come to be from man. Whence what they say is true, namely, that the form of bed is not the nature, but the wood is. For if wood should germinate, a bed would not come to be, but wood. Therefore, as this form, which does not arise through germination, is not nature but art, so the form which arises from generation is nature. But the form of a natural thing does arise through generation, for man comes to be from man. Therefore the form of a natural thing is nature.
Tertiam rationem ponit ibi: amplius autem natura etc.: quae talis est. Natura potest significari ut generatio, puta si natura dicatur nativitas. Sic igitur natura dicta ut generatio, idest nativitas, est via in naturam. Haec enim est differentia inter actiones et passiones, quod actiones denominantur a principiis, passiones vero a terminis. Unumquodque enim denominatur ab actu, qui est principium actionis et terminus passionis. Non enim ita est in passionibus sicut in actionibus: medicatio enim non dicitur via in medicinam, sed in sanitatem; necesse est enim quod medicatio sit a medicina, non in medicinam. Sed natura dicta ut generatio, idest nativitas, non sic se habet ad naturam sicut medicatio ad medicinam: sed se habet ad naturam sicut ad terminum, cum sit passio. Id enim quod nascitur, a quodam in quoddam venit inquantum nascitur: unde id quod nascitur, denominatur ab eo in quod, non ab eo ex quo. Id autem in quod tendit nativitas, est forma: forma igitur est natura. 155. He gives his third argument where he says, ‘We also speak...’ (193 b 13). Nature can be signified as a generation, for instance, if we should call it birth. Thus nature in the sense of generation, i.e., birth, is the way to nature. For the difference between actions and passions is that actions are named from their principles while passions are named from their terminations. For each thing is named from act, which is the principle of action and the termination of passion. But naming is not the same in passions and actions. For medication is not called the way to medicine, but the way to health. It is necessary for medication to proceed from medicine, not to medicine. But nature in the sense of generation, i.e., birth, is not related to nature as medication is related to medicine. Rather it is related to nature as to a termination, since it is a passion. For that which is born, insofar as it is born, comes from something to something. Hence that which is born is named from that to which it proceeds, and not from that from which it proceeds. That, however, to which birth tends is form. Therefore form is nature.
Deinde cum dicit: sed forma et natura etc., ostendit quod natura quae est forma dupliciter dicitur, scilicet de forma incompleta et forma completa. Et hoc patet in generatione secundum quid, ut puta cum aliquid fit album: nam albedo est forma completa, et privatio albedinis est quodammodo species, inquantum coniungitur nigredini, quae est forma imperfecta. Sed utrum in generatione simplici, quae est substantiarum, sit aliquid quod sit privatio et contrarium simul, ita quod formae substantiales sint contrariae, vel non, considerandum est posterius in quinto huius, et in libro de generatione. 156. Next where he says, ‘Shape and nature...’ (193 b 19), he shows that the nature which is form is used in two ways, i.e., of the incomplete form and the complete form. This is clear in accidental generation, for example, when something becomes white. For whiteness is a complete form, and the privation of whiteness is in some way a species, insofar as it is joined to blackness, which is an imperfect form. But whether or not in simple generation, which is the generation of substances, there is something which is a privation and also a contrary, so that substantial forms are contraries, must be considered later in Book VI and in De Generatione et Corruptione I:3.

Lectio 3 (193 b 22-194 a 11)
HOW PHYSICS AND MATHEMATICS DIFFER IN THEIR CONSIDERATION OF THE SAME THING
Chapter 2 cont.
Ἐπεὶ δὲ διώρισται ποσαχῶς ἡ φύσις, μετὰ τοῦτο θεωρητέον τίνι διαφέρει ὁ μαθηματικὸς τοῦ φυσικοῦ We have distinguished, then, the different ways in which the term 'nature' is used. The next point to consider is how the mathematician differs from the physicist.
(καὶ γὰρ ἐπίπεδα καὶ στερεὰ ἔχει τὰ φυσικὰ σώματα καὶ μήκη καὶ στιγμάς, περὶ ὧν σκοπεῖ ὁ μαθηματικός)· Obviously physical bodies contain surfaces and volumes, lines and points, and these are the subject-matter of mathematics.
ἔτι εἰ ἡ ἀστρολογία ἑτέρα ἢ μέρος τῆς φυσικῆς· εἰ γὰρ τοῦ φυσικοῦ τὸ τί ἐστιν ἥλιος ἢ σελήνη εἰδέναι, τῶν δὲ συμβεβηκότων καθ' αὑτὰ μηδέν, ἄτοπον, ἄλλως τε καὶ ὅτι φαίνονται λέγοντες οἱ περὶ φύσεως καὶ περὶ σχήματος σελήνης καὶ ἡλίου, καὶ δὴ καὶ πότερον σφαιροειδὴς ἡ γῆ καὶ ὁ κόσμος ἢ οὔ. Further, is astronomy different from physics or a department of it? It seems absurd that the physicist should be supposed to know the nature of sun or moon, but not to know any of their essential attributes, particularly as the writers on physics obviously do discuss their shape also and whether the earth and the world are spherical or not.
περὶ τούτων μὲν οὖν πραγματεύεται καὶ ὁ μαθηματικός, ἀλλ' οὐχ ᾗ φυσικοῦ σώματος πέρας ἕκαστον· οὐδὲ τὰ συμβεβηκότα θεωρεῖ ᾗ τοιούτοις οὖσι συμβέβηκεν· Now the mathematician, though he too treats of these things, nevertheless does not treat of them as the limits of a physical body; nor does he consider the attributes indicated as the attributes of such bodies.
διὸ καὶ χωρίζει· χωριστὰ γὰρ τῇ νοήσει κινήσεώς ἐστι, καὶ οὐδὲν διαφέρει, οὐδὲ γίγνεται ψεῦδος χωριζόντων. That is why he separates them; for in thought they are separable from motion, and it makes no difference, nor does any falsity result, if they are separated.
λανθάνουσι δὲ τοῦτο ποιοῦντες καὶ οἱ τὰς ἰδέας λέγοντες· τὰ γὰρ φυσικὰ (194a.) χωρίζουσιν ἧττον ὄντα χωριστὰ τῶν μαθηματικῶν. The holders of the theory of Forms do the same, though they are not aware of it; for they separate the objects of physics, which are less separable than those of mathematics.
γίγνοιτο δ' ἂν τοῦτο δῆλον, εἴ τις ἑκατέρων πειρῷτο λέγειν τοὺς ὅρους, καὶ αὐτῶν καὶ τῶν συμβεβηκότων. τὸ μὲν γὰρ περιττὸν ἔσται καὶ τὸ ἄρτιον καὶ τὸ εὐθὺ καὶ τὸ καμπύλον, ἔτι δὲ ἀριθμὸς καὶ γραμμὴ καὶ σχῆμα, ἄνευ κινήσεως, σὰρξ δὲ καὶ ὀστοῦν καὶ ἄνθρωπος οὐκέτι, ἀλλὰ ταῦτα ὥσπερ ῥὶς σιμὴ ἀλλ' οὐχ ὡς τὸ καμπύλον λέγεται. This becomes plain if one tries to state in each of the two cases the definitions of the things and of their attributes. 'Odd' and 'even', 'straight' and 'curved', and likewise 'number', 'line', and 'figure', do not involve motion; not so 'flesh' and 'bone' and 'man'—these are defined like 'snub nose', not like 'curved'.
δηλοῖ δὲ καὶ τὰ φυσικώτερα τῶν μαθημάτων, οἷον ὀπτικὴ καὶ ἁρμονικὴ καὶ ἀστρολογία· ἀνάπαλιν γὰρ τρόπον τιν' ἔχουσιν τῇ γεωμετρίᾳ. ἡ μὲν γὰρ γεωμετρία περὶ γραμμῆς φυσικῆς σκοπεῖ, ἀλλ' οὐχ ᾗ φυσική, ἡ δ' ὀπτικὴ μαθηματικὴν μὲν γραμμήν, ἀλλ' οὐχ ᾗ μαθηματικὴ ἀλλ' ᾗ φυσική. Similar evidence is supplied by the more physical of the branches of mathematics, such as optics, harmonics, and astronomy. These are in a way the converse of geometry. While geometry investigates physical lines but not qua physical, optics investigates mathematical lines, but qua physical, not qua mathematical.
Postquam philosophus ostendit quid sit natura et quot modis dicitur, hic consequenter intendit ostendere de quibus considerat scientia naturalis. 157. After the Philosopher has explained what nature is and how many ways the name is used, he here intends to show what it is that natural science considers.
Et dividitur in partes duas: in prima ostendit quomodo differat naturalis a mathematico; in secunda ostendit ad quae se extendat consideratio scientiae naturalis, ibi: quoniam autem natura et cetera. This section is divided into two parts. First he shows how natural science differs from mathematics. Secondly, where he says, ‘Since nature has...’ (194 a 12; L4 #166), he designates that to which the consideration of natural science extends.
Circa primum tria facit: primo movet quaestionem; secundo ponit rationes ad quaestionem, ibi: etenim plana etc.; tertio solvit quaestionem, ibi: de his igitur negotiatur et cetera. Concerning the first part he makes three points. First he states the question. Secondly, where he says, ‘Obviously physical bodies...’ (193 b 23 #158), he gives his reasons for [raising] the question. Thirdly, he answers the question where he says, ‘Now the mathematician...’ (193 b 31 #159).
Dicit ergo primo quod postquam determinatum est quot modis natura dicitur, considerandum est in quo differat mathematicus a naturali philosopho. He says, therefore, first that after the uses of the name ‘nature’ have been determined, it is necessary to consider how mathematics differs from natural philosophy.
Deinde cum dicit: etenim plana etc., ponit rationes ad quaestionem. Quarum prima talis est.. 158. Next where he says, ‘Obviously physical bodies...’ (193 b 23), he gives his reasons for [raising] the question. The first of these is as follows.
Quaecumque scientiae considerant eadem subiecta, vel sunt eaedem, vel una est pars alterius; sed mathematicus philosophus considerat de punctis, lineis et superficiebus et corporibus, et similiter naturalis (quod probat ex hoc quod corpora naturalia habent plana, idest superficies, et firma, idest soliditates, et longitudines et puncta; oportet autem quod naturalis consideret de omnibus quae insunt corporibus naturalibus); ergo videtur quod scientia naturalis et mathematica vel sint eaedem, vel una sit pars alterius Whenever sciences consider the same subjects, they are either the same science, or one is a part of the other. But the mathematical philosopher considers points and lines and surfaces and bodies, and so does the natural philosopher. (For he proves from the fact that natural bodies have planes, i.e., surfaces, and volumes, i.e., solidity, and lengths and points. Moreover the natural philosopher must consider all things that are in natural bodies.) Therefore it seems that natural science and mathematics are either the same or that one is a part of the other.
Secundam rationem ponit ibi: amplius, astrologia et cetera. Et circa hanc rationem primo movet quaestionem, utrum astrologia sit omnino altera a naturali philosophia, vel sit pars eius. Manifestum est enim quod est pars mathematicae: unde si est etiam pars naturalis philosophiae, sequitur quod mathematica et physica conveniunt ad minus in hac parte. He gives the second reason where he says, ‘Further, is astronomy...’ (193 b 25). In connection with this reason he raises the question whether astronomy is altogether other than natural philosophy or a part of it. For it is clear that astronomy is a part of mathematics. Whence, if it is also a part of natural philosophy, it follows that mathematics and physics agree at least in this part.
Quod autem astrologia sit pars physicae, probat dupliciter. Primo quidem per rationem talem. Ad quemcumque pertinet cognoscere substantias et naturas aliquarum rerum, ad eum etiam pertinet considerare accidentia illarum; sed ad naturalem pertinet considerare naturam et substantiam solis et lunae, cum sint quaedam corpora naturalia; ergo ad eum pertinet etiam considerare per se accidentia ipsorum. That astronomy is a part of physics he proves in two ways. First by the following argument. To whomever it belongs to know the substances and natures of certain things, also belongs the consideration of their accidents. But it belongs to the natural philosopher to consider the nature and substance of the sun and the moon, since they are certain natural bodies. Therefore it belongs to the natural philosopher to consider their per se accidents.
Hoc etiam probat ex consuetudine philosophorum: nam philosophi naturales inveniuntur determinasse de figura solis et lunae et terrae et totius mundi, circa quod insudat etiam astrologorum intentio. Sic igitur astrologia et scientia naturalis conveniunt non solum in eisdem subiectis, sed etiam in consideratione eorundem accidentium, et in demonstratione earundem conclusionum. Unde videtur quod astrologia sit pars physicae; et per consequens physica non totaliter differat a mathematica. He proves this also from the custom of the philosophers. For natural philosophers are found to have treated the shape of the sun and of the moon and of the earth and of the whole world. And these are topics which claim the attention of the astronomers. Therefore astronomy and natural science agree not only in [having] the same subjects but also in the consideration of the same accidents, and in demonstrating the same conclusions. Whence it seems that astronomy is a part of physics, and as a result physics does not differ totally from mathematics.
Deinde cum dicit: de his quidem igitur etc., solvit praemissam quaestionem. Et circa hoc duo facit: primo ponit solutionem; secundo confirmat eam, ibi: fiet autem utique et cetera. 159. Next where he says, ‘Now the mathematician...’ (193 b 3 1), he answers the question raised above. Concerning this he makes two points. First he gives his solution, and secondly he confirms it, where he says, ‘This becomes plain...’ (194 a 1 #163).
Circa primum tria facit: primo solvit quaestionem; secundo concludit quoddam corollarium ex praedictis, ibi: unde et abstrahit etc.; tertio excludit errorem, ibi: latet autem hoc et cetera. Concerning the first part he makes three points. First he answers the question. Secondly, where he says, ‘That is why he separates...’ (193 b 33 #161), he concludes to a sort of corollary from the above. Thirdly, where he says, ‘The holders of...’ (193 b 35 #162), he excludes an error.
Dicit ergo primo quod mathematicus et naturalis determinant de eisdem, scilicet punctis, lineis et superficiebus et huiusmodi, sed non eodem modo. Non enim mathematicus determinat de eis inquantum unumquodque eorum est terminus corporis naturalis; neque considerat ea quae accidunt eis inquantum sunt termini corporis naturalis; per quem modum de eis considerat scientia naturalis. Non est autem inconveniens quod idem cadat sub consideratione diversarum scientiarum secundum diversas considerationes. 160. He says, therefore, first that the mathematician and the natural philosopher treat the same things, i.e., points, and lines, and surfaces, and things of this sort, but not in the same way. For the mathematician does not treat these things insofar as each of them is a boundary of a natural body, nor does he consider those things which belong to them insofar as they are the boundaries of a natural body. But this is the way in which natural science treats them. And, it is not inconsistent that the same thing should fall under the consideration of different sciences according to different points of view.
Deinde cum dicit: unde et abstrahit etc., concludit quoddam corollarium ex praedictis. Quia enim mathematicus considerat lineas et puncta et superficies et huiusmodi et accidentia eorum non inquantum sunt termini corporis naturalis, ideo dicitur abstrahere a materia sensibili et naturali. Et causa quare potest abstrahere, est ista: quia secundum intellectum sunt abstracta a motu. 161. Next where he says, ‘That is why he separates...’(193 b 33), he concludes to a sort of corollary from what he has just said. Because the mathematician does not consider lines, and points, and surfaces, and things of this sort, and their accidents, insofar as they are the boundaries of a natural body, he is said to abstract from sensible and natural matter. And the reason why he is able to abstract is this: according to the intellect these things are abstracted from motion.
Ad cuius causae evidentiam considerandum est quod multa sunt coniuncta secundum rem, quorum unum non est de intellectu alterius: sicut album et musicum coniunguntur in aliquo subiecto, et tamen unum non est de intellectu alterius, et ideo potest unum separatim intelligi sine alio. Et hoc est unum intellectum esse abstractum ab alio. Manifestum est autem quod posteriora non sunt de intellectu priorum, sed e converso: unde priora possunt intelligi sine posterioribus, et non e converso. Sicut patet quod animal est prius homine, et homo est prius hoc homine (nam homo se habet ex additione ad animal, et hic homo ex additione ad hominem); et propter hoc homo non est de intellectu animalis, nec Socrates de intellectu hominis: unde animal potest intelligi absque homine, et homo absque Socrate et aliis individuis. Et hoc est abstrahere universale a particulari. As evidence for this reason we must note that many things are joined in the thing, but the understanding of one of them is not derived from the understanding of another. Thus white and musical are joined in the same subject, nevertheless the understanding of one of these is not derived from an understanding of the other. And so one can be separately understood without the other. And this one is understood as abstracted from the other. It is clear, however, that the posterior is not derived from the understanding of the prior, but conversely. Hence the prior can be understood without the posterior, but not conversely. Thus it is clear that animal is prior to man, and man is prior to this man (for man is had by addition to animal, and this man by addition to man). And because of this our understanding of man is not derived from our understanding of animal, nor our understanding of Socrates from our understanding of man. Hence animal can be understood without man, and man without Socrates and other individuals. And this is to abstract the universal from the particular.
Similiter autem inter accidentia omnia quae adveniunt substantiae, primo advenit ei quantitas, et deinde qualitates sensibiles et actiones et passiones et motus consequentes sensibiles qualitates. Sic igitur quantitas non claudit in sui intellectu qualitates sensibiles vel passiones vel motus: claudit tamen in sui intellectu substantiam. Potest igitur intelligi quantitas sine materia subiecta motui et qualitatibus sensibilibus, non tamen absque substantia. Et ideo huiusmodi quantitates et quae eis accidunt, sunt secundum intellectum abstracta a motu et a materia sensibili, non autem a materia intelligibili, ut dicitur in VII Metaphys. In like manner, among all the accidents which come to substance, quantity comes first, and then the sensible qualities, and actions and passions, and the motions consequent upon sensible qualities. Therefore quantity does not embrace in its intelligibility the sensible qualities or the passions or the motions. Yet it does include substance in its intelligibility. Therefore quantity can be understood without matter, which is subject to motion, and without sensible qualities, but not without substance. And thus quantities and those things which belong to them are understood as abstracted from motion and sensible matter, but not from intelligible matter, as is said in Metaphysics, VII:10.
Quia igitur sic sunt abstracta a motu secundum intellectum, quod non claudunt in suo intellectu materiam sensibilem subiectam motui; ideo mathematicus potest ea abstrahere a materia sensibili. Et nihil differt quantum ad veritatem considerationis, utrum sic vel sic considerentur. Quamvis enim non sint abstracta secundum esse, non tamen mathematici abstrahentes ea secundum intellectum, mentiuntur: quia non asserunt ea esse extra materiam sensibilem (hoc enim esset mendacium), sed considerant de eis absque consideratione materiae sensibilis, quod absque mendacio fieri potest: sicut aliquis potest considerare albedinem absque musica, et vere, licet conveniant in eodem subiecto: non tamen esset vera consideratio, si assereret album non esse musicum. Since, therefore, the objects of mathematics are abstracted from motion according to the intellect, and since they do not include in their intelligibility sensible matter, which is a subject of motion, the mathematician can abstract them from sensible matter. And it makes no difference as far as the truth is concerned whether they are considered one way or the other. For although the objects of mathematics are not separated according to existence, the mathematicians, in abstracting them according to their understanding, do not lie, because they do not assert that these things exist apart from sensible matter (for this would be a lie). But they consider them without any consideration of sensible matter, which can be done without lying. Thus one can truly consider the white without the musical, even though they exist together in the same subject. But it would not be a true consideration if one were to assert that the white is not musical.
Deinde cum dicit: latet autem hoc facientes etc., excludit ex praedictis errorem Platonis. 162. Next where he says, “The holders of the theory...’ (193 b 35), he excludes from what he has said an error of Plato.
Quia enim latebat eum quomodo intellectus vere posset abstrahere ea quae non sunt abstracta secundum esse, posuit omnia quae sunt abstracta secundum intellectum, esse abstracta secundum rem. Unde non solum posuit mathematica abstracta, propter hoc quod mathematicus abstrahit a materia sensibili; sed etiam posuit ipsas res naturales abstractas, propter hoc quod naturalis scientia est de universalibus et non de singularibus. Unde posuit hominem esse separatum, et equum et lapidem et alia huiusmodi; quae quidem separata dicebat esse ideas: cum tamen naturalia sint minus abstracta quam mathematica. Mathematica enim sunt omnino abstracta a materia sensibili secundum intellectum, quia materia sensibilis non includitur in intellectu mathematicorum, neque in universali neque in particulari: sed in intellectu specierum naturalium includitur quidem materia sensibilis, sed non materia individualis; in intellectu enim hominis includitur caro et os, sed non haec caro et hoc os. Since Plato was puzzled as to how the intellect could truly separate those things which were not separated in their existence, he held that all things which are separated in the understanding are separated in the thing. Hence he not only held that mathematical entities are separated, because of the fact that the mathematician abstracts from sensible matter, but he even held that natural things themselves are separated, because of the fact that natural science is of universals and not of singulars. Hence he held that man is separated, and horse, and stone, and other such things. And he said these separated things are ideas, although natural things are less abstract than mathematical entities. For mathematical entities are altogether separated from sensible matter in the understanding, because sensible matter is not included in the understanding of the mathematicals, neither in the universal nor in the particular. But sensible matter is included in the understanding of natural things, whereas individual matter is not. For in the understanding of man flesh and bone is included, but not this flesh and this bone.
Deinde cum dicit: fiet autem utique manifestum etc., manifestat positam solutionem dupliciter: primo quidem per differentiam definitionum quas assignat mathematicus et naturalis; secundo per scientias medias, ibi: demonstrant autem et quae magis et cetera. 163. Next where he says, ‘This becomes plain...’ (194 a 1), he clarifies the solution he has given in two ways, first by means of the difference in the definitions which the mathematician and the natural philosopher assign, and secondly by means of the intermediate sciences, where he says, ‘Similar evidence...’ (194 a 7 #164).
Dicit ergo primo quod hoc quod dictum est de diverso modo considerationis mathematici et physici, fiet manifestum si quis tentaverit dicere definitiones naturalium et mathematicorum, et accidentium eorum: quia mathematica, ut par et impar, et rectum et curvum, et numerus et linea et figura, definiuntur sine motu et materia; non autem caro et os et homo: sed horum definitio est sicut definitio simi, in cuius definitione ponitur subiectum sensibile, scilicet nasus; non autem sicut definitio curvi, in cuius definitione non ponitur aliquod subiectum sensibile. He says, therefore, first that what has been said of the different modes of consideration of the mathematician and the natural philosopher will become evident if one attempts to give definitions of the mathematicals, and of natural things and of their accidents. For the mathematicals, such as equal and unequal, straight and curved, and number, and line, and figure, are defined without motion and matter, but this is not so with flesh and bone and man. Rather the definition of these latter is like the definition of the snub in which definition a sensible subject is placed, i.e., nose. But this is not the case with the definition of the curved in which definition a sensible subject is not placed.
Et sic ex ipsis definitionibus naturalium et mathematicorum apparet quod supra dictum est de differentia mathematici et naturalis. And thus from the very definitions of natural things and of the mathematicals, what was said above [#160ff] about the difference between the mathematician and the natural philosopher is apparent.
Deinde cum dicit: demonstrant autem etc., probat idem per scientias quae sunt mediae inter mathematicam et naturalem. 164. Next where he says, ‘Similar evidence...’ (194 a 7), he proves the same thing by means of those sciences which are intermediates between mathematics and natural philosophy.
Dicuntur autem scientiae mediae, quae accipiunt principia abstracta a scientiis pure mathematicis, et applicant ad materiam sensibilem; sicut perspectiva applicat ad lineam visualem ea quae demonstrantur a geometria circa lineam abstractam; et harmonica, idest musica, applicat ad sonos ea quae arithmeticus considerat circa proportiones numerorum; et astrologia considerationem geometriae et arithmeticae applicat ad caelum et ad partes eius. Those sciences are called intermediate sciences which take principles abstracted by the purely mathematical sciences and apply them to sensible matter. For example, perspective applies to the visual line those things which are demonstrated by geometry about the abstracted line; and harmony, that is music, applies to sound those things which arithmetic considers about the proportions of numbers; and astronomy applies the consideration of geometry and arithmetic to the heavens and its parts.
Huiusmodi autem scientiae, licet sint mediae inter scientiam naturalem et mathematicam, tamen dicuntur hic a philosopho esse magis naturales quam mathematicae, quia unumquodque denominatur et speciem habet a termino: unde, quia harum scientiarum consideratio terminatur ad materiam naturalem, licet per principia mathematica procedant, magis sunt naturales quam mathematicae. However, although sciences of this sort are intermediates between natural science and mathematics, they are here said by the Philosopher to be more natural than mathematical, because each thing is named and takes its species from its terminus. Hence, since the consideration of these sciences is terminated in natural matter, then even though they proceed by mathematical principles, they are more natural than mathematical sciences.
Dicit ergo de huiusmodi scientiis, quod contrario modo se habent cum scientiis quae sunt pure mathematicae, sicut geometria vel arithmetica. Nam geometria considerat quidem de linea quae habet esse in materia sensibili, quae est linea naturalis: non tamen considerat de ea inquantum est in materia sensibili, secundum quod est naturalis, sed abstracte, ut dictum est. Sed perspectiva e converso accipit lineam abstractam secundum quod est in consideratione mathematici, et applicat eam ad materiam sensibilem; et sic determinat de ea non inquantum est mathematica, sed inquantum est physica. He says, therefore, that sciences of this sort are established in a way contrary to the sciences which are purely mathematical, such as geometry or arithmetic. For geometry considers the line which has existence in sensible matter, which is the natural line. But it does not consider it insofar as it is in sensible matter, insofar as it is natural, but abstractly, as was said [#160ff]. But perspective conversely takes the abstract line which is in the consideration of mathematics, and applies it to sensible matter, and thus treats it not insofar as it is a mathematical, but insofar as it is a physical thing.
Ex ipsa ergo differentia scientiarum mediarum ad scientias pure mathematicas, apparet quod supra dictum est. Nam si huiusmodi scientiae mediae abstracta applicant ad materiam sensibilem, manifestum est quod mathematicae e converso ea quae sunt in materia sensibili abstrahunt. Therefore from this difference between intermediate sciences and the purely mathematical sciences, what was said above is clear. For if intermediate sciences of this sort apply the abstract to sensible matter, it is clear that mathematics conversely separates those things which are in sensible matter.
Et per hoc etiam patet responsio ad id quod supra obiiciebatur de astrologia. Unde astrologia est magis naturalis quam mathematica. Unde non est mirum si communicet in conclusionibus cum scientia naturali. 165. And from this it is clear what his answer is to the objection raised above [#158] concerning astronomy. For astronomy is a natural science more than a mathematical science. Hence it is no wonder that astronomy agrees in its conclusions with natural science.
Quia tamen non est pure naturalis, per aliud medium eandem conclusionem demonstrat. Sicut quod terra sit sphaerica demonstratur a naturali per medium naturale, ut puta quia partes eius undique et aequaliter concurrunt ad medium: ab astrologo autem ex figura eclipsis lunaris, vel ex hoc quod non eadem sidera ex omni parte terrae aspiciuntur. However, since it is not a purely natural science, it demonstrates the same conclusion through another method. Thus, the fact that the earth is spherical is demonstrated by natural science by a natural method, e.g., because its parts everywhere and equally come together at the middle. But this is demonstrated by astronomy from the figure of the lunar eclipse, or from the fact that the same stars are not seen from every part of the earth.

Lectio 4 (194 a 12-b 15)
PHYSICS CONSIDERS NOT ONLY MATTER BUT ALSO EVERY FORM EXISTING IN MATTER
Chapter 2 cont.
ἐπεὶ δ' ἡ φύσις διχῶς, τό τε εἶδος καὶ ἡ ὕλη, ὡς ἂν εἰ περὶ σιμότητος σκοποῖμεν τί ἐστιν, οὕτω θεωρητέον· ὥστ' οὔτ' ἄνευ ὕλης τὰ τοιαῦτα οὔτε κατὰ τὴν ὕλην. Since 'nature' has two senses, the form and the matter, we must investigate its objects as we would the essence of snubness. That is, such things are neither independent of matter nor can be defined in terms of matter only.
καὶ γὰρ δὴ καὶ περὶ τούτου ἀπορήσειεν ἄν τις, ἐπεὶ δύο αἱ φύσεις, περὶ ποτέρας τοῦ φυσικοῦ. ἢ περὶ τοῦ ἐξ ἀμφοῖν; ἀλλ' εἰ περὶ τοῦ ἐξ ἀμφοῖν, καὶ περὶ ἑκατέρας. πότερον οὖν τῆς αὐτῆς ἢ ἄλλης ἑκατέραν γνωρίζειν; Here too indeed one might raise a difficulty. Since there are two natures, with which is the physicist concerned? Or should he investigate the combination of the two? But if the combination of the two, then also each severally. Does it belong then to the same or to different sciences to know each severally?
εἰς μὲν γὰρ τοὺς ἀρχαίους ἀποβλέψαντι δόξειεν ἂν εἶναι τῆς ὕλης (ἐπὶ μικρὸν γάρ τι μέρος Ἐμπεδοκλῆς καὶ Δημόκριτος τοῦ εἴδους καὶ τοῦ τί ἦν εἶναι ἥψαντο)· If we look at the ancients, physics would to be concerned with the matter. (It was only very slightly that Empedocles and Democritus touched on the forms and the essence.)
εἰ δὲ ἡ τέχνη μιμεῖται τὴν φύσιν, τῆς δὲ αὐτῆς ἐπιστήμης εἰδέναι τὸ εἶδος καὶ τὴν ὕλην μέχρι του (οἷον ἰατροῦ ὑγίειαν καὶ χολὴν καὶ φλέγμα, ἐν οἷς ἡ ὑγίεια, ὁμοίως δὲ καὶ οἰκοδόμου τό τε εἶδος τῆς οἰκίας καὶ τὴν ὕλην, ὅτι πλίνθοι καὶ ξύλα· ὡσαύτως δὲ καὶ ἐπὶ τῶν ἄλλων), καὶ τῆς φυσικῆς ἂν εἴη τὸ γνωρίζειν ἀμφοτέρας τὰς φύσεις. But if on the other hand art imitates nature, and it is the part of the same discipline to know the form and the matter up to a point (e.g. the doctor has a knowledge of health and also of bile and phlegm, in which health is realized, and the builder both of the form of the house and of the matter, namely that it is bricks and beams, and so forth): if this is so, it would be the part of physics also to know nature in both its senses.
ἔτι τὸ οὗ ἕνεκα καὶ τὸ τέλος τῆς αὐτῆς, καὶ ὅσα τούτων ἕνεκα. ἡ δὲ φύσις τέλος καὶ οὗ ἕνεκα (ὧν γὰρ συνεχοῦς τῆς κινήσεως οὔσης ἔστι τι τέλος, τοῦτο <�τὸ> ἔσχατον καὶ τὸ οὗ ἕνεκα· διὸ καὶ ὁ ποιητὴς γελοίως προήχθη εἰπεῖν "ἔχει τελευτήν, ἧσπερ οὕνεκ' ἐγένετο"· βούλεται γὰρ οὐ πᾶν εἶναι τὸ ἔσχατον τέλος, ἀλλὰ τὸ βέλτιστον)· ἐπεὶ καὶ ποιοῦσιν αἱ τέχναι τὴν ὕλην αἱ μὲν ἁπλῶς αἱ δὲ εὐεργόν, καὶ χρώμεθα ὡς ἡμῶν ἕνεκα πάντων ὑπαρχόντων (ἐσμὲν γάρ πως καὶ ἡμεῖς τέλος· διχῶς γὰρ τὸ οὗ ἕνεκα· εἴρηται δ' ἐν τοῖς περὶ φιλοσοφίας). δύο (194b.) δὲ αἱ ἄρχουσαι τῆς ὕλης καὶ γνωρίζουσαι τέχναι, ἥ τε χρωμένη καὶ τῆς ποιητικῆς ἡ ἀρχιτεκτονική. διὸ καὶ ἡ χρωμένη ἀρχιτεκτονική πως, διαφέρει δὲ ᾗ ἡ μὲν τοῦ εἴδους γνωριστική, ἡ ἀρχιτεκτονική, ἡ δὲ ὡς ποιητική, τῆς ὕλης· ὁ μὲν γὰρ κυβερνήτης ποῖόν τι τὸ εἶδος τοῦ πηδαλίου γνωρίζει καὶ ἐπιτάττει, ὁ δ' ἐκ ποίου ξύλου καὶ ποίων κινήσεων ἔσται. ἐν μὲν οὖν τοῖς κατὰ τέχνην ἡμεῖς ποιοῦμεν τὴν ὕλην τοῦ ἔργου ἕνεκα, ἐν δὲ τοῖς φυσικοῖς ὑπάρχει οὖσα. Again, 'that for the sake of which', or the end, belongs to the same department of knowledge as the means. But the nature is the end or 'that for the sake of which'. For if a thing undergoes a continuous change and there is a stage which is last, this stage is the end or 'that for the sake of which'. (That is why the poet was carried away into making an absurd statement when he said 'he has the end for the sake of which he was born'. For not every stage that is last claims to be an end, but only that which is best.) For the arts make their material (some simply 'make' it, others make it serviceable), and we use everything as if it was there for our sake. (We also are in a sense an end. 'That for the sake of which' has two senses: the distinction is made in our work On Philosophy.) The arts, therefore, which govern the matter and have knowledge are two, namely the art which uses the product and the art which directs the production of it. That is why the using art also is in a sense directive; but it differs in that it knows the form, whereas the art which is directive as being concerned with production knows the matter. For the helmsman knows and prescribes what sort of form a helm should have, the other from what wood it should be made and by means of what operations. In the products of art, however, we make the material with a view to the function, whereas in the products of nature the matter is there all along.
ἔτι τῶν πρός τι ἡ ὕλη· ἄλλῳ γὰρ εἴδει ἄλλη ὕλη. Again, matter is a relative term: to each form there corresponds a special matter.
μέχρι δὴ πόσου τὸν φυσικὸν δεῖ εἰδέναι τὸ εἶδος καὶ τὸ τί ἐστιν; ἢ ὥσπερ ἰατρὸν νεῦρον ἢ χαλκέα χαλκόν, μέχρι τοῦ τίνος [γὰρ] ἕνεκα ἕκαστον, καὶ περὶ ταῦτα ἅ ἐστι χωριστὰ μὲν εἴδει, ἐν ὕλῃ δέ; ἄνθρωπος γὰρ ἄνθρωπον γεννᾷ καὶ ἥλιος. πῶς δ' ἔχει τὸ χωριστὸν καὶ τί ἐστι, φιλοσοφίας ἔργον διορίσαι τῆς πρώτης. How far then must the physicist know the form or essence? Up to a point, perhaps, as the doctor must know sinew or the smith bronze (i.e. until he understands the purpose of each): and the physicist is concerned only with things whose forms are separable indeed, but do not exist apart from matter. Man is begotten by man and by the sun as well. The mode of existence and essence of the separable it is the business of the primary type of philosophy to define.
Postquam philosophus ostendit differentiam inter naturalem et mathematicum, hic ostendit ad quid se extendat consideratio naturalis. 166. Having shown the difference between natural science and mathematics, the Philosopher here designates that to which the consideration of natural science extends.
Et circa hoc duo facit: primo ostendit quod ad naturalem pertinet considerare formam et materiam; secundo ostendit quid sit terminus considerationis naturalis circa formam, ibi: usque ad quantum et cetera. Concerning this he makes two points. First he shows that it pertains to natural science to consider both form and matter. Secondly, where he says, ‘How far then. (194 b 10 #175), he points out the limits of natural science in its consideration of form.
Circa primum duo facit: primo ex praemissis concludit propositum; secundo movet dubitationes circa determinatum, ibi: etenim iam et cetera. Concerning the first part he makes two points. First he draws his conclusion from what has gone before. Secondly, where he says, ‘Here too indeed...’ (194 a 15 #168), he raises difficulties against his own position.
Dicit ergo primo quod quia natura dicitur dupliciter, scilicet de materia et forma, ut supra dictum est, sic est considerandum in scientia naturali, sicut cum intendimus de simo quid est: tunc enim non solum formam, idest curvitatem, sed etiam materiam, idest nasum attendimus. Unde in scientia naturali neque est consideratio sine materia sensibili, neque etiam solum secundum materiam, sed etiam secundum formam. 167. He says, therefore, first that since ‘nature’ is used in two ways, i.e., of the matter and of the form, as was said above [L2 #145ff], so must it be considered in natural science. Thus when we consider what the snub is, we consider not only its form, i.e., its curvature, but we also consider its matter, i.e., the nose. Hence in natural science nothing is considered, in respect to matter and also in respect to form, without sensible matter.
Et est notandum quod iste processus Aristotelis includit duo media. And it must be noted that this argument of Aristotle includes two approaches.
Per unum quorum sic potest argumentari. Naturalis philosophus debet considerare de natura; sed natura est tam forma quam materia; ergo debet tam de materia quam de forma considerare. In one way we can argue as follows. The natural philosopher ought to consider nature. But nature is both form and matter. Therefore he ought to consider both matter and form.
Per aliud vero sic. Naturalis differt a mathematico, ut dictum est, quia consideratio naturalis est sicut consideratio simi, consideratio vero mathematici est sicut consideratio curvi; sed consideratio simi est consideratio formae et materiae; ergo et consideratio naturalis est consideratio utriusque. The other way is as follows. The natural philosopher differs from the mathematician, as was said above [L3 #163], because the consideration of the natural philosopher is like the consideration of the snub, whereas that of the mathematician is like the consideration of the curved. But the consideration of the snub is a consideration of the form and the matter. Therefore the consideration of the natural philosopher is a consideration of both.
Deinde cum dicit: etenim iam etc., movet circa praemissa dubitationem duplicem. 168. Next where he says, ‘Here too indeed...’ (194 a 15), he raises a two-fold problem relative to what he has just said.
Quarum prima est: cum natura dicatur de materia et de forma, utrum scientia naturalis sit tantum de materia, vel tantum de forma, vel de eo quod est ex utroque compositum. The first is as follows. Since ‘nature’ is used for matter and form, is natural science about the matter alone, or the form alone, or about that which is a composite of both?
Secunda dubitatio est: supposito quod de utroque consideret scientia naturalis, utrum sit eadem scientia naturalis quae consideret de forma et materia, vel alia et alia de utroque. The second problem is as follows. Supposing that natural science does consider both, is it the same natural science which considers form and matter, or are there different sciences which consider each?
Deinde cum dicit: in antiquos quidem enim etc., solvit praedictas dubitationes, et maxime secundam; ostendens quod ad eiusdem scientiae naturalis considerationem pertinet considerare de forma et de materia. Nam prima quaestio satis videbatur soluta esse per hoc quod dixerat, quod consideratio naturalis est sicut cum intendimus de simo quid sit. 169. Next where he says, ‘If we look at the ancients...’ (194 a 19), he answers the above mentioned problems, and especially the second, showing that it pertains to the consideration of the same natural science to consider both form and matter. For the first question seems to have been adequately answered by what he has said, namely, that the consideration of natural science is the same as the consideration of what the snub is.
Circa hoc ergo duo facit. Primo ponit quid antiqui sensisse videntur. Et dicit quod si aliquis velit aspicere ad dicta antiquorum naturalium, videtur quod scientia naturalis non sit nisi de materia: quia vel nihil tractaverunt de forma, vel aliquid modicum; sicut tetigerunt eam Democritus et Empedocles, inquantum posuerunt aliquid fieri ex multis secundum aliquem determinatum modum mixtionis vel congregationis. Concerning this, therefore, he makes two points. First he states what the ancients seem to have thought. He says that if one wishes to look at the sayings of the ancient natural philosophers, it seems that [for them] natural science is concerned only with matter. For they said either nothing about form, or some small bit, as when Democritus and Empedocles touched upon it insofar as they held that a thing comes to be from many according to a determinate mode of mixing or joining.
Secundo, ibi: si autem ars imitatur etc., ostendit propositum tribus rationibus: quarum prima talis est. 170. Secondly, where he says, ‘But if on the other hand...’(194 a 21), he proves his position with three arguments, the first of which is as follows.
Ars imitatur naturam; oportet igitur quod sic se habeat scientia naturalis circa naturalia, sicut se habet scientia artificialis circa artificialia. Sed eiusdem scientiae artificialis est cognoscere materiam et formam usque ad aliquem certum terminum; sicut medicus cognoscit sanitatem ut formam, et choleram et phlegma et huiusmodi sicut materiam in qua est sanitas, nam in contemperatione humorum sanitas consistit; et similiter aedificator considerat formam domus, et lateres et ligna, quae sunt materia domus; et ita est in omnibus aliis artibus. Ergo eiusdem scientiae naturalis est cognoscere tam materiam quam formam. Art imitates nature. Therefore natural science must be related to natural things as the science of the artificial is related to artificial things. But it belongs to the same science of the artificial to know the matter and the form up to a certain point, as the doctor knows health as a form, and bile and phlegm and such things as the matter in which health is. For health consists in a harmony of humours. And in like manner the builder considers the form of the house and also the bricks and the wood which are the matter of the house. And so it is in all the other arts. Therefore it belongs to the same natural science to know both the matter and the form.
Eius autem quod ars imitatur naturam, ratio est, quia principium operationis artificialis cognitio est; omnis autem nostra cognitio est per sensus a rebus sensibilibus et naturalibus accepta: unde ad similitudinem rerum naturalium in artificialibus operamur. Ideo autem res naturales imitabiles sunt per artem, quia ab aliquo principio intellectivo tota natura ordinatur ad finem suum, ut sic opus naturae videatur esse opus intelligentiae, dum per determinata media ad certos fines procedit: quod etiam in operando ars imitatur. 171. The reason for saying that art imitates nature is as follows. Knowledge is the principle of operation in art. But an of our knowledge is through the senses and taken from sensible, natural things. Hence in artificial things we work to a likeness of natural things. And so imitable natural things are [i.e., are produced] through art, because all nature is ordered to its end by some intellective principle, so that the work of nature thus seems to be the work of intelligence as it proceeds to certain ends through determinate means. And this order is imitated by art in its operation.
Secundam rationem ponit ibi: adhuc quod cuius causa et cetera. 172. He gives the second argument where he says, ‘Again “that for the sake of which”...’ (194 a 27).
Eiusdem scientiae est considerare finem et ea quae sunt ad finem: et hoc ideo quia ratio eorum quae sunt ad finem, a fine sumitur. Sed natura quae est forma, est finis materiae; ergo eiusdem scientiae naturalis est considerare materiam et formam. It belongs to the same science to consider the end and those things which are for the end. This is so because the reason [ ratio ] for those things which are for the end is taken from the end. But nature, which is form, is the end of matter. Therefore it belongs to the same natural science to consider matter and form.
Quod autem forma sit finis materiae, sic probat. Ad hoc quod aliquid sit finis alicuius motus continui, duo requiruntur: quorum unum est quod sit ultimum motus, et aliud est quod sit cuius causa fit. Aliquid enim potest esse ultimum, sed non est cuius causa fit; unde non habet rationem finis. Et quia de ratione finis est quod sit cuius causa fit, poeta hoc apposuit, quod derisorie se habet dicere finem cuius causa fit. Videtur enim esse nugatio, sicut si diceretur homo animal: quia animal est de ratione hominis, sicut et cuius causa fit de ratione finis. Vult enim poeta quod non omne ultimum sit finis, sed illud quod est ultimum et optimum, hoc est cuius causa fit. 173. That form is the end of matter he proves as follows. In order for something to be the end of a continuous motion two things are required. First it must be the final stage of the motion, and secondly it must be that for the sake of which the thing comes to be. For something can be last, but not be that for the sake of which something comes to be, and hence not have the nature [ ratio ] of an end. And because it is of the nature [ ratio ] of an end that it be that for the sake of which something comes to be, the poet maintained that it would be a jest to say that the end is that for the sake of which something comes to be. This seemed to him to be a trifle, for just as if we were to say ‘man animal’ because animal is in the nature [ ratio ] of man, so also, that for the sake of which something comes to be is in the nature [ ratio ] of end. For the poet wished to say that not every last thing is an end, but rather only that which is last and best. This is that for the sake of which something comes to be.
Et quidem quod forma sit ultimum generationis, hoc est per se manifestum. Sed quod sit cuius causa fit respectu materiae, manifestat per similitudinem in artibus. Inveniuntur enim quaedam artes quae faciunt materiam: quarum quaedam faciunt eam simpliciter, sicut ars figuli facit lateres, quae sunt materia domus; quaedam vero faciunt eam operose, idest materiam praeexistentem in natura disponunt ad receptionem formae, sicut ars carpentaria praeparat ligna ad formam navis. And indeed that the form is last in generation is per se evident. But that it is that for the sake of which something comes to be with respect to matter is made clear by a simile taken from the arts. Certain arts make matter. And of these some make it simply, as the art of the moulder makes tiles which are the matter of a house, while others make it operative, i.e., they dispose matter pre-existing in nature for the reception of a form, as the art of the carpenter prepares wood for the form of a ship.
Item considerandum est quod nos utimur omnibus quae sunt secundum artem facta, sicut propter nos existentibus. Nos enim sumus quodammodo finis omnium artificialium. Et dicit quodammodo: quia sicut dictum est in philosophia prima, dupliciter dicitur id cuius causa fit, scilicet cuius et quo; sicut finis domus ut cuius est habitator, ut quo est habitatio. It must further be noted that we use all things which are made by art as though they exist for us. For we are in a sense the end of all artificial things. And he says ‘in a sense’ because, as is said in first philosophy [ Metaph. XII:7], that for the sake of which something comes to be is used in two ways, i.e., ‘of which’ and ‘for which’. Thus the end of a house as ‘of which’ is the dweller, as ‘for which’ it is a dwelling.
Ex his igitur accipere possumus quod duae artes sunt principantes materiam, idest quae praecipiunt artibus facientibus materiam, et cognoscentes, idest diiudicantes de ipsis; una scilicet quae utitur, et alia quae est factiva artificiati, inducens scilicet formam. Et haec est sicut architectonica respectu eius quae disponit materiam, sicut navifactiva respectu carpentariae, quae secat ligna: unde etiam oportet quod ipsa ars usualis sit quodammodo architectonica, idest principalis ars, respectu factivae. From this, therefore, we can conclude that matter is ordered by two arts, that is, those that direct the arts which make matter, and those that pass judgment on the former. Thus there is one art which uses, and another art which is productive of the artifact, as it were, inducing the form. And this latter art is architectonic with reference to that which disposes matter. Thus the art of the ship builder is architectonic with respect to the art of the carpenter who cuts wood. Hence it is necessary that the art which uses be in a sense architectonic, i.e., the principal art, with respect to the productive art.
Quamvis igitur utraque sit architectonica, scilicet usualis et factiva, tamen differunt: quia usualis est architectonica inquantum est cognoscitiva et diiudicativa de forma; alia autem, quae est architectonica tanquam factiva formae, est cognoscitiva materiae, idest diiudicat de materia. Et hoc manifestat per exemplum. Usus enim navis pertinet ad gubernatorem; et sic gubernatoria est usualis; et sic est architectonica respectu navifactivae, et cognoscit et diiudicat de forma. Et hoc est quod dicit, quod gubernator cognoscit et instituit qualis debeat esse forma temonis. Alius autem, scilicet factor navis, cognoscit et diiudicat ex quibus et qualibus lignis debeat fieri navis. Therefore, although each is architectonic, i.e., the art which uses and the productive art, they nevertheless differ. For the art which uses is architectonic insofar as it knows and passes judgment on the form, whereas the other, which is architectonic as productive of the form, knows the matter, i.e., passes judgment on the matter. He makes this clear by an example. The use of a ship pertains to the navigator, and thus the art of the navigator is an art which uses, and hence it is architectonic with respect to the art of the ship builder, and knows and passes judgment on the form. He says that the navigator knows and judges what the shape of the rudder should be. The other art, however, i.e., the art of the ship builder, knows and judges from what wood and from what kind of wood the ship should be made.
Sic ergo manifestum est quod ars quae inducit formam, praecipit arti quae facit vel disponit materiam; ars autem quae utitur artificiato iam facto, praecipit arti quae inducit formam. It is clear, therefore, that the art which produces the form directs the art which makes or disposes the matter. However the art which uses the completed artifact directs the art which produces the form.
Ex quo possumus accipere quod sic se habet materia ad formam, sicut forma ad usum. Sed usus est cuius causa fit artificiatum: ergo et forma est cuius causa est materia in artificialibus. Et sicut in his quae sunt secundum artem, nos facimus materiam propter opus artis, quod est ipsum artificiatum; ita in naturalibus materia inest a natura non a nobis facta, nihilominus eundem habens ordinem ad formam, scilicet quod est propter formam. From this, then, we can conclude that matter is related to form as form is related to use. But use is that for the sake of which the artifact comes to be. Therefore, form also is that for the sake of which matter is in artificial things. And so as in those things which are according to art we make matter for the sake of the work of art, which is the artifact itself, likewise matter is in natural things from nature, and not made by us; nevertheless it has the same ordination to form, i.e., it is for the sake of form.
Unde sequitur quod eiusdem scientiae naturalis sit considerare materiam et formam. Hence it follows that it belongs to the same natural science to consider the matter and the form.
Tertiam rationem ponit ibi: amplius eorum etc.: quae talis est. 174. He gives the third argument where he says, ‘Again matter is...’ (194 b 9). The argument is as follows.
Eorum quae sunt ad aliquid, una est scientia. Sed materia est de numero eorum quae sunt ad aliquid, quia dicitur ad formam. Quod non ideo dicitur quasi ipsa materia sit in genere relationis, sed quia cuilibet formae determinatur propria materia: et hoc est quod subdit, quod sub alia forma oportet esse aliam materiam. Unde relinquitur quod eiusdem scientiae naturalis sit considerare formam et materiam. Things which are related belong to one science. But matter is one of the things which are related, because it is spoken of in relation to form. However it is not spoken of as if matter itself were in the genus of relation, but rather because a proper matter is determined for each form. And he adds that there must be a different matter under a different form. Hence it follows that the same natural science considers form and matter.
Deinde cum dicit: usque ad quantum etc., ostendit quantum se extendat consideratio scientiae naturalis circa formam. 175. Next where he says, ‘How far then...’ (194 b 10), he shows to what extent natural science considers form.
Et circa hoc duo facit: primo movet quaestionem hanc, scilicet usque ad quantum oporteat naturalem considerare de forma et quidditate rei (nam considerare formas et quidditates rerum absolute videtur pertinere ad philosophum primum); Concerning this he makes two points. First he raises the question, i.e., to what extent should natural science consider the form and quiddity of a thing. (For to consider the forms and quiddities of things absolutely seems to belong to first philosophy.)
secundo solvit quod sicut medicus considerat nervum, et faber aes usque ad aliquem terminum, ita et naturalis formas. Medicus enim non considerat de nervo inquantum est nervus, hoc enim pertinet ad naturalem, sed inquantum est subiectum sanitatis; et similiter faber de aere non inquantum est aes, sed inquantum est subiectum statuae aut alicuius huiusmodi. Et similiter naturalis non considerat de forma inquantum est forma, sed inquantum est in materia. Et ideo sicut medicus in tantum considerat de nervo in quantum pertinet ad sanitatem, cuius causa considerat nervum; similiter naturalis in tantum considerat de forma in quantum habet esse in materia. Secondly, he answers the question by saying that as the doctor considers nerves, and the smith considers bronze, up to a certain point, so also the natural philosopher considers forms. For the doctor does not consider nerve insofar as it is nerve, for this belongs to the natural philosopher. Rather he considers it as a subject of health. So also the smith does not consider bronze insofar as it is bronze, but insofar as it is the subject of a statue or something of the sort. So also the natural philosopher does not consider form insofar as it is form, but insofar as it is in matter. And thus, as the doctor considers nerve only insofar as it pertains to health, for the sake of which he considers nerve, so also the natural philosopher considers form only insofar as it has existence in matter.
Et ideo terminus considerationis scientiae naturalis est circa formas quae quidem sunt aliquo modo separatae, sed tamen esse habent in materia. Et huiusmodi formae sunt animae rationales: quae quidem sunt separatae inquantum intellectiva virtus non est actus alicuius organi corporalis, sicut virtus visiva est actus oculi; sed in materia sunt inquantum dant esse naturale tali corpori. And so the last things considered by natural science are forms which are, indeed, in some way separated, but which have existence in matter. And rational souls are forms of this sort. For such souls are, indeed, separated insofar as the intellective power is not the act of a corporeal organ, as the power of seeing is the act of an eye. But they are in matter insofar as they give natural existence to such a body.
Et quod sint in materia, per hoc probat, quod forma cuiuslibet rei generatae ex materia est forma in materia: ad hoc enim terminatur generatio, ut forma sit in materia. Sed homo generatur ex materia et ab homine, quasi ab agente proprio, et a sole tanquam ab agente universali respectu generabilium: unde sequitur quod anima, quae est forma humana, sit forma in materia. Unde usque ad animam rationalem se extendit consideratio naturalis, quae est de formis. That such souls are in matter he proves as follows. The form of anything generated from matter is a form which is in matter. For the generation is-terminated when the form is in matter. But man is generated from matter and by man, as by a proper agent, and by the sun, as by a universal agent with respect to the generable. Whence it follows that the soul, which is the human form, is a form in matter. Hence the consideration of natural science about forms extends to the rational soul.
Sed quomodo se habeant formae totaliter a materia separatae, et quid sint, vel etiam quomodo se habeat haec forma, idest anima rationalis, secundum quod est separabilis et sine corpore existere potens, et quid sit secundum suam essentiam separabile, hoc determinare pertinet ad philosophum primum. But how forms are totally separated from matter, and what they are, or even how this form, i.e., the rational soul, exists insofar as it is separable and capable of existence without a body, and what it is according to its separable essence, are questions which pertain to first philosophy.

Lectio 5 (194 b 16-195 a 27)
PHYSICS DETERMINES WHAT THE CAUSES ARE
AND HOW MANY SPECIES OF CAUSES THERE ARE
Chapter 3
Διωρισμένων δὲ τούτων ἐπισκεπτέον περὶ τῶν αἰτίων, ποῖά τε καὶ πόσα τὸν ἀριθμόν ἐστιν. ἐπεὶ γὰρ τοῦ εἰδέναι χάριν ἡ πραγματεία, εἰδέναι δὲ οὐ πρότερον οἰόμεθα ἕκαστον πρὶν ἂν λάβωμεν τὸ διὰ τί περὶ ἕκαστον (τοῦτο δ' ἐστὶ τὸ λαβεῖν τὴν πρώτην αἰτίαν), δῆλον ὅτι καὶ ἡμῖν τοῦτο ποιητέον καὶ περὶ γενέσεως καὶ φθορᾶς καὶ πάσης τῆς φυσικῆς μεταβολῆς, ὅπως εἰδότες αὐτῶν τὰς ἀρχὰς ἀνάγειν εἰς αὐτὰς πειρώμεθα τῶν ζητουμένων ἕκαστον. Now that we have established these distinctions, we must proceed to consider causes, their character and number. Knowledge is the object of our inquiry, and men do not think they know a thing till they have grasped the 'why' of (which is to grasp its primary cause). So clearly we too must do this as regards both coming to be and passing away and every kind of physical change, in order that, knowing their principles, we may try to refer to these principles each of our problems.
ἕνα μὲν οὖν τρόπον αἴτιον λέγεται τὸ ἐξ οὗ γίγνεταί τι ἐνυπάρχοντος, οἷον ὁ χαλκὸς τοῦ ἀνδριάντος καὶ ὁ ἄργυρος τῆς φιάλης καὶ τὰ τούτων γένη· ἄλλον δὲ τὸ εἶδος καὶ τὸ παράδειγμα, τοῦτο δ' ἐστὶν ὁ λόγος ὁ τοῦ τί ἦν εἶναι καὶ τὰ τούτου γένη (οἷον τοῦ διὰ πασῶν τὰ δύο πρὸς ἕν, καὶ ὅλως ὁ ἀριθμός) καὶ τὰ μέρη τὰ ἐν τῷ λόγῳ. ἔτι ὅθεν ἡ ἀρχὴ τῆς μεταβολῆς ἡ πρώτη ἢ τῆς ἠρεμήσεως, οἷον ὁ βουλεύσας αἴτιος, καὶ ὁ πα τὴρ τοῦ τέκνου, καὶ ὅλως τὸ ποιοῦν τοῦ ποιουμένου καὶ τὸ μεταβάλλον τοῦ μεταβαλλομένου. ἔτι ὡς τὸ τέλος· τοῦτο δ' ἐστὶν τὸ οὗ ἕνεκα, οἷον τοῦ περιπατεῖν ἡ ὑγίεια· διὰ τί γὰρ περιπατεῖ; φαμέν "ἵνα ὑγιαίνῃ", καὶ εἰπόντες οὕτως οἰόμεθα ἀποδεδωκέναι τὸ αἴτιον. καὶ ὅσα δὴ κινήσαντος ἄλλου μεταξὺ γίγνεται τοῦ τέλους, οἷον τῆς ὑγιείας ἡ ἰσχνασία ἢ ἡ (195a.) κάθαρσις ἢ τὰ φάρμακα ἢ τὰ ὄργανα· πάντα γὰρ ταῦτα τοῦ τέλους ἕνεκά ἐστιν, διαφέρει δὲ ἀλλήλων ὡς ὄντα τὰ μὲν ἔργα τὰ δ' ὄργανα. τὰ μὲν οὖν αἴτια σχεδὸν τοσαυταχῶς λέγεται, In one sense, then, (1) that out of which a thing comes to be and which persists, is called 'cause', e.g. the bronze of the statue, the silver of the bowl, and the genera of which the bronze and the silver are species. In another sense (2) the form or the archetype, i.e. the statement of the essence, and its genera, are called 'causes' (e.g. of the octave the relation of 2:1, and generally number), and the parts in the definition. Again (3) the primary source of the change or coming to rest; e.g. the man who gave advice is a cause, the father is cause of the child, and generally what makes of what is made and what causes change of what is changed. Again (4) in the sense of end or 'that for the sake of which' a thing is done, e.g. health is the cause of walking about. ('Why is he walking about?' we say. 'To be healthy', and, having said that, we think we have assigned the cause.) The same is true also of all the intermediate steps which are brought about through the action of something else as means towards the end, e.g. reduction of flesh, purging, drugs, or surgical instruments are means towards health. All these things are 'for the sake of' the end, though they differ from one another in that some are activities, others instruments. This then perhaps exhausts the number of ways in which the term 'cause' is used.
συμβαίνει δὲ πολλαχῶς λεγομένων τῶν αἰτίων καὶ πολλὰ τοῦ αὐτοῦ αἴτια εἶναι, οὐ κατὰ συμβεβηκός, οἷον τοῦ ἀνδριάντος καὶ ἡ ἀνδριαντοποιικὴ καὶ ὁ χαλκός, οὐ καθ' ἕτερόν τι ἀλλ' ᾗ ἀνδριάς, ἀλλ' οὐ τὸν αὐτὸν τρόπον, ἀλλὰ τὸ μὲν ὡς ὕλη τὸ δ' ὡς ὅθεν ἡ κίνησις. ἔστιν δέ τινα καὶ ἀλλήλων αἴτια, οἷον τὸ πονεῖν τῆς εὐεξίας καὶ αὕτη τοῦ πονεῖν· ἀλλ' οὐ τὸν αὐτὸν τρόπον, ἀλλὰ τὸ μὲν ὡς τέλος τὸ δ' ὡς ἀρχὴ κινήσεως. ἔτι δὲ τὸ αὐτὸ τῶν ἐναντίων ἐστίν· ὃ γὰρ παρὸν αἴτιον τοῦδε, τοῦτο καὶ ἀπὸν αἰτιώμεθα ἐνίοτε τοῦ ἐναντίου, οἷον τὴν ἀπουσίαν τοῦ κυβερνήτου τῆς τοῦ πλοίου ἀνατροπῆς, οὗ ἦν ἡ παρουσία αἰτία τῆς σωτηρίας. As the word has several senses, it follows that there are several causes of the same thing not merely in virtue of a concomitant attribute), e.g. both the art of the sculptor and the bronze are causes of the statue. These are causes of the statue qua statue, not in virtue of anything else that it may be—only not in the same way, the one being the material cause, the other the cause whence the motion comes. Some things cause each other reciprocally, e.g. hard work causes fitness and vice versa, but again not in the same way, but the one as end, the other as the origin of change. Further the same thing is the cause of contrary results. For that which by its presence brings about one result is sometimes blamed for bringing about the contrary by its absence. Thus we ascribe the wreck of a ship to the absence of the pilot whose presence was the cause of its safety.
ἅπαντα δὲ τὰ νῦν εἰρημένα αἴτια εἰς τέτταρας πίπτει τρόπους τοὺς φανερωτάτους. τὰ μὲν γὰρ στοιχεῖα τῶν συλλαβῶν καὶ ἡ ὕλη τῶν σκευαστῶν καὶ τὸ πῦρ καὶ τὰ τοιαῦτα τῶν σωμάτων καὶ τὰ μέρη τοῦ ὅλου καὶ αἱ ὑποθέσεις τοῦ συμπεράσματος ὡς τὸ ἐξ οὗ αἴτιά ἐστιν, τούτων δὲ τὰ μὲν ὡς τὸ ὑποκείμενον, οἷον τὰ μέρη, τὰ δὲ ὡς τὸ τί ἦν εἶναι, τό τε ὅλον καὶ ἡ σύνθεσις καὶ τὸ εἶδος· τὸ δὲ σπέρμα καὶ ὁ ἰατρὸς καὶ ὁ βουλεύσας καὶ ὅλως τὸ ποιοῦν, πάντα ὅθεν ἡ ἀρχὴ τῆς μεταβολῆς ἢ στάσεως [ἢ κινήσεως]· τὰ δ' ὡς τὸ τέλος καὶ τἀγαθὸν τῶν ἄλλων· τὸ γὰρ οὗ ἕνεκα βέλτιστον καὶ τέλος τῶν ἄλλων ἐθέλει εἶναι· διαφερέτω δὲ μηδὲν εἰπεῖν αὐτὸ ἀγαθὸν ἢ φαινόμενον ἀγαθόν. τὰ μὲν οὖν αἴτια ταῦτα καὶ τοσαῦτά ἐστι τῷ εἴδει· All the causes now mentioned fall into four familiar divisions. The letters are the causes of syllables, the material of artificial products, fire, etc., of bodies, the parts of the whole, and the premisses of the conclusion, in the sense of 'that from which'. Of these pairs the one set are causes in the sense of substratum, e.g. the parts, the other set in the sense of essence—the whole and the combination and the form. But the seed and the doctor and the adviser, and generally the maker, are all sources whence the change or stationariness originates, while the others are causes in the sense of the end or the good of the rest; for 'that for the sake of which' means what is best and the end of the things that lead up to it. (Whether we say the 'good itself or the 'apparent good' makes no difference.) Such then is the number and nature of the kinds of cause.
Postquam philosophus ostendit de quibus considerat scientia naturalis, hic incipit ostendere ex quibus causis demonstret. 176. Having shown what natural science considers, the Philosopher here begins to designate the causes from which it should demonstrate.
Et dividitur in partes duas: in prima determinat de causis; in secunda vero ostendit ex quibus causis naturalis demonstret, ibi: quoniam autem causae quatuor et cetera. This section is divided into two parts. First he treats the causes. Secondly, where he says, ‘Now the causes...’ (198 a 23; L11 #241), he points out the causes from which natural science should demonstrate.
Circa primum duo facit: primo ostendit necessitatem determinandi de causis; secundo incipit de causis determinare, ibi: uno quidem modo et cetera. Concerning the first part he makes two points. First he shows the need for treating the causes. Secondly, where he says, ‘In one sense...’ (194 b 23 #177), he begins to treat the causes.
Dicit ergo primo quod postquam determinatum est quid cadat sub consideratione scientiae naturalis, restat considerandum de causis, quae et quot sunt. He says, therefore, first that after it has been determined what falls under the consideration of natural science, there remains to be considered the causes—what they are and how many there are.
Et hoc ideo, quia hoc negotium quo intendimus de natura tractare, non ordinatur ad operationem, sed ad scientiam: quia nos non possumus facere res naturales, sed solum de eis scientiam habere.. This is so because the business of studying nature is not ordered to operation, but to science. For we are not able to make natural things, but only to have science of them.
Sed nos non opinamur nos scire unumquodque, nisi cum accipimus propter quid, quod est accipere causam: unde manifestum est quod hoc observandum est nobis circa generationem et corruptionem et omnem naturalem mutationem, ut cognoscamus causas, et reducamus unumquodque de quo quaeritur propter quid, in proximam causam Now we do not think that we know anything unless we grasp the ‘why’, which is to grasp the cause. Hence it is clear that we must observe generation and corruption and every natural change in such a way that we know the causes and that we reduce to its proximate cause each thing concerning which we seek the ‘why’.
Hoc autem ideo dicit, quia considerare de causis inquantum huiusmodi, proprium est philosophi primi: nam causa in eo quod causa est non dependet a materia secundum esse, eo quod in his etiam quae a materia sunt separata, invenitur ratio causae. Sed a philosopho naturali assumitur consideratio de causis propter aliquam necessitatem; nec tamen assumitur ab eo considerare de causis nisi secundum quod sunt causae naturalium mutationum. He says this because the consideration of causes insofar as they are causes is proper to first philosophy. For a cause insofar as it is a cause does not depend upon matter for its existence, because the nature [ ratio ] of cause is found also in those things which are separated from matter. But the consideration of causes because of a certain necessity is taken up by the natural philosopher. However he considers causes only insofar as they are the causes of natural mutations.
Deinde cum dicit: uno quidem modo etc., determinat de causis. 177. Next where he says, ‘In one sense...’ (194 b 23), he treats the causes.
Et circa hoc tria facit: primo assignat diversas species causarum manifestas; secundo de quibusdam immanifestis causis determinat, ibi: dicitur autem fortuna etc.; tertio ostendit quod non sunt plures neque pauciores, ibi: quae autem sunt causae et cetera. Concerning this he makes three points. First he names the clearly diverse species of causes. Secondly, where he says, ‘But chance also (195 b 31; L7 #198), he treats certain less obvious causes. Thirdly, where he says, ‘They differ...’ (197 a 36; L10 #226) he shows that the causes are neither more nor less.
Prima dividitur in duas: in prima determinat species causarum; in secunda determinat modos diversarum causarum secundum unamquamque speciem, ibi: modi autem causarum et cetera. The first part is divided into two parts. First he treats the species of causes. Secondly, where hip says, ‘Now the modes...’ (195 a 27; L6 #187), he treats the modes of diverse causes in each species.
Circa primum duo facit: primo inducit diversas species causarum; secundo reducit eas ad quatuor, ibi: omnes autem nunc et cetera. Concerning the first part he makes two points. First he sets forth the different species of causes. Secondly, where he says, ‘All the causes... (195 a 15 #184) he reduces them to four.
Circa primum duo facit: primo ponit diversitatem causarum; secundo exponit quaedam consequentia ex diversitate praedicta, ibi: contingit autem multipliciter et cetera. Concerning the first part he makes two points. First he sets forth the different causes. Secondly, where he says, ‘As the word...’ (195 a 3 #182), he points out certain consequences which follow from the above mentioned diversity.
Dicit ergo primo quod uno modo dicitur causa ex quo fit aliquid cum insit, sicut aes dicitur causa statuae et argentum causa phialae: et etiam genera horum dicuntur causae earundem rerum, sicut metallum vel liquabile vel huiusmodi. 178. He says, therefore, first that in one way a cause is said to be that from which something comes to be when it is in it, as bronze is said to be the cause of a statue and* silver the cause of a vase. The genera of these things, i.e., the metallic, or the liquifiable, and such things, are also called causes of these same things.
Apposuit autem cum insit, ad differentiam privationis et contrarii: nam statua quidem fit ex aere, quod inest statuae iam factae; fit etiam ex infigurato, quod quidem non inest statuae iam factae. Unde aes est causa statuae, non autem infiguratum, cum sit principium per accidens tantum, ut in primo dictum est. He adds ‘when it is in it’ in order to differentiate this cause from the privation and the contrary. For the statue, indeed, comes to be from bronze, which is in the statue when it is made. It also comes to be from the unshaped, which, however, is not in the statue when it is made. Hence bronze is a cause of statue, but the unshaped is not, since it is only a per accidens principle, as was said in Book I [L13 #112].
Secundo modo dicitur causa species et exemplum: et hoc dicitur causa inquantum est ratio quidditativa rei; hoc enim est per quod scimus de unoquoque quid est. 179. Secondly a cause is said to be the species and exemplar. This is called a cause insofar as it is the quidditative nature [ ratio ] of the thing, for this is that through which we know of each thing ‘what it is’.
Et sicut dictum est circa materiam quod etiam genera materiae dicuntur causa, ita et genera speciei dicuntur causa. Et ponit exemplum in quadam consonantia musicae quae vocatur diapason, cuius forma est proportio dupla, quae est duorum ad unum. Nam proportiones numerales applicatae ad sonos sicut ad materiam, consonantias musicales constituunt: et cum duo vel duplum sit forma consonantiae quae est diapason, et genus duorum, quod est numerus, est causa. Sicut enim dicimus quod forma diapason est proportio duorum ad unum, quae est proportio dupla, ita possumus dicere quod forma diapason, est proportio duorum ad unum, quae est multiplicitas. Et ita ad hunc modum causae reducuntur omnes partes quae ponuntur in definitione: nam partes speciei ponuntur in definitione, non autem partes materiae, ut dicitur in VII Metaphys. Nec est hoc contra id quod supra dictum est, quod in definitione rerum naturalium ponitur materia: nam in definitione speciei non ponitur materia individualis, sed materia communis; sicut in definitione hominis ponuntur carnes et ossa, non autem hae carnes et haec ossa. And as was said above that even the genera of matter are called causes, so also the genera of a species are called causes. And he gives as an example that harmony of music which is called the octave. The form of an octave is a proportion of the double, which is a relation of two to one. For musical harmonies are constituted by the application of numerical proportions to sounds as to matter. And since two or the double is the form of that harmony which is the octave, the genus of two, which is number, is also a cause. Thus just as we say that the form of the octave is that proportion of two to one which is the proportion of the double, so also we can say that the form of the octave is that proportion of two to one which is multiplicity. And so all of the parts which are placed in the definition are reduced to this mode of cause. For the parts of the species are placed in the definition, but not the parts of the matter, as is said in Metaphysics, VII:10. Nor is this contrary to what was said above [L3 #163] about matter being placed in the definitions of natural things. For individual matter is not placed in the definition of the species, but common matter is. Thus flesh and bones are placed in’ the definition of man, but not this flesh and these bones.
Natura igitur speciei constituta ex forma et materia communi, se habet ut formalis respectu individui quod participat talem naturam; et pro tanto hic dicitur quod partes quae ponuntur in definitione, pertinent ad causam formalem. The nature of the species, therefore, which is constituted of form and common matter, is related as a formal cause to the individual which participates in such a nature, and to this extent it is said that the parts which are placed in the definition pertain to the formal cause.
Considerandum est etiam quod duo posuit pertinentia ad quidditatem rei, scilicet speciem et exemplum, propter diversas opiniones de essentiis rerum. It must be noted, however, that he posits two things which pertain to the quiddity of the thing, i.e., the species and the exemplar. For there is a diversity of opinions concerning the essences of things.
Nam Plato posuit naturas specierum esse quasdam formas abstractas, quas dicebat exemplaria et ideas; et propter hoc posuit exemplum vel paradigma. Plato held that the natures of species are certain abstracted forms, which he called exemplars and ideas, and because of this he posited the exemplar or paradigm.
Naturales autem philosophi qui aliquid de forma tetigerunt, posuerunt formas in materia; et propter hoc nominavit speciem. However those natural philosophers who said something about form placed the forms in matter, and because of this he named them species.
Ulterius autem dicit quod alio modo dicitur causa a quo est principium motus vel quietis; sicut consilians dicitur causa, et pater filii, et omne commutans commutati. 180. Next he says that that from which there is a beginning of motion or rest is in some way called a cause. Thus one who gives advice is a cause, and the father is a cause of the son, and everything which brings about a change is a cause of that which is changed.
Circa huiusmodi autem causas considerandum est quod quadruplex est causa efficiens, scilicet perficiens, praeparans, adiuvans et consilians. It must be noted with reference to causes of this sort that there are four kinds of efficient cause, namely, the perfecting, the preparing, the assisting, and the advising causes.
Perficiens enim est, quod dat complementum motui vel mutationi; sicut quod introducit formam substantialem in generatione. The perfecting cause is that which gives fulfilment to motion or mutation, as that which introduces the substantial form in generation.
Praeparans autem seu disponens est, quod aptat materiam seu subiectum ad ultimum complementum. The preparing or disposing cause is that which renders matter or the subject suitable for its ultimate completion.
Adiuvans vero est, quod non operatur ad proprium finem, sed ad finem alterius. The assisting cause is that which does not operate for its own proper end, but for the end of another.
Consilians autem in his quae agunt a proposito, est quod dat agenti formam per quam agit. Nam agens a proposito agit per suam scientiam, quam consilians sibi tradit; sicut et in rebus naturalibus generans dicitur movere gravia vel levia, inquantum dat formam per quam moventur. The advising cause, which operates in those things which act because of something proposed to them, is that which gives to the agent the form through which it acts. For the agent acts because of something proposed to him through his knowledge, which the advisor has given to him, just as in natural things the generator is said to move the heavy or the light insofar as he gives the form through which they are moved.
Quartum autem modum causae ponit, quod aliquid dicitur causa ut finis; et hoc est cuius causa aliquid fit, sicut sanitas dicitur ambulationis. Et hoc patet quia respondetur ad quaestionem factam propter quid: cum enim quaerimus propter quid ambulat? Dicimus ut sanetur; et hoc dicentes opinamur nos assignare causam. Ideo autem potius probat de fine quod sit causa quam de aliis, quia hoc minus videbatur propterea quia finis est ultimum in generatione. 181. Further, he posits a fourth mode of cause. A thing is called a cause as an end. This is that for the sake of which something comes to be, as health is said to be a cause of walking. And this is evident because it answers the proposed question ‘why’. For when we ask, ‘Why does he walk?’, we say, ‘That he may become healthy’; and we say this thinking that we assign a cause. And thus he gives more proof that the end is a cause than that the other things are causes, because the end is less evident, inasmuch as it is last in generation.
Et ulterius addit quod omnia quae sunt intermedia inter primum movens et ultimum finem, omnia sunt quodammodo fines: sicut medicus ad sanitatem inducendam extenuat corpus, et sic sanitas est finis maciei; maciem autem operatur per purgationem; purgationem autem per potionem; potionem autem praeparat per aliqua instrumenta. Unde omnia haec sunt quodammodo finis: nam macies est finis purgationis, et purgatio potionis, et potio organorum, et organa sunt fines in operatione vel inquisitione organorum. And he adds further that all things which are intermediates between the first mover and the ultimate end are in some way ends. Thus the doctor reduces the body in order to produce health, and so health is the end of thinness. But thinness is produced by purgation~ and purgation is produced by a drug, and the drug is prepared by instruments. Hence all of these things are in some way ends, for the thinness is the end of the purging, the purging is the end of the drug, and the drug is the end of the instruments, and the instruments are the ends in the operation or in the seeking for the instruments.
Et sic patet quod ista intermedia differunt ad invicem, inquantum quaedam sunt organa et quaedam opera, operata scilicet per organa. Et hoc inducit ne aliquis credat quod solum id quod est ultimum sit causa sicut cuius gratia, propter hoc quod hoc nomen finis ultimum quoddam esse videtur. Est igitur omnis finis ultimum non simpliciter, sed respectu alicuius. And thus it is clear that these intermediate things differ from each other insofar as some of them are instruments and some of them are operations performed by instruments. And he brings this out lest anyone think that only that which is last is a cause in the sense of ‘that for the sake of which’. For the name ‘end’ seems to refer to something which is last. Thus every end is last, not simply, but in respect to something.
Et ultimo concludit quod fere tot modis dicuntur causae. Et addit fere, propter causas quae sunt per accidens, sicut sunt casus et fortuna. He finally concludes that this is perhaps all the ways in which the name ‘cause’ is used. He adds ‘perhaps’ because of the causes which are per accidens, such as chance and fortune.
Deinde cum dicit: contingit autem multipliciter etc., manifestat tria consequentia ex iam dicta causarum diversitate. 182. Next where he says, ‘As the word has...’ (195 a 3), he makes clear three things which follow from what he has said about the different causes.
Quorum primum est quod cum causae dicantur multipliciter, contingit unius et eiusdem esse multas causas per se et non per accidens; sicut causa statuae est ars statuifica ut efficiens, et aes ut materia. Et inde est quod aliquando unius rei assignantur plures definitiones secundum diversas causas; sed perfecta definitio omnes causas complectitur. The first point is that since there are many causes, then one and the same thing has many causes per se, and not per accidens. Thus the art of the sculptor is a cause of a statue as an efficient cause, and bronze is a cause as matter. And so it is that many definitions of one thing are sometimes given in accordance with the different causes. But the perfect definition embraces all of the causes.
Secundum est quod quaedam sibi invicem sunt causae secundum diversam speciem causae; sicut laborare est causa efficiens bonae habitudinis, bona autem habitudo est causa finalis laboris. Nihil enim prohibet aliquid esse prius et posterius altero secundum diversas rationes: finis enim est prius secundum rationem, sed posterius in esse; agens autem e converso. Et similiter forma est prior quam materia secundum rationem complementi, materia autem est prius quam forma generatione et tempore in omni eo quod movetur de potentia in actum. The second point is that some things are causes of each other in respect to different species of cause. Thus work is an efficient cause of a good habit, yet a good habit is a final cause of work. For nothing prevents a thing from being prior and posterior to another according to different aspects [ ratio ]. The end is prior according to reason [ ratio ], but posterior in existence; the converse is true of the agent. And in like manner, the form is prior to matter in respect to the nature [ ratio ] of being a complement, but the matter is prior to form in respect to generation and time in everything which is moved from potency to act.
Tertium est quod idem est causa contrariorum quandoque; sicut per suam praesentiam gubernator est causa salutis navis, per absentiam autem suam causa est submersionis eius. The third point is that the same thing is, at times, the cause of contraries. Thus through his presence the navigator is the cause of the safety of the ship, through his absence, however, he is a cause of its sinking.
Deinde cum dicit: omnes autem nunc dictae causae etc., reducit omnes causas superius enumeratas in quatuor species: et dicit quod omnes causae quae enumeratae sunt superius, reducuntur ad quatuor modos, qui sunt manifesti. Nam elementa, idest litterae, sunt causae syllabarum; et similiter terra est causa vasorum et argentum phialae; et ignis et similia, corpora scilicet simplicia, sunt causae corporum; et similiter quaelibet partes sunt causa totius; et suppositiones, idest propositiones syllogismi, sunt causa conclusionum: et omnia ista habent unam rationem causae, prout dicitur causa id ex quo fit aliquid: hoc enim est commune in omnibus praemissis. 183. Next where he says, ‘All the causes...’(195 a 15), he reduces all the causes mentioned above to four species. He says that all the causes enumerated above are reduced to four modes, which are evident. For the elements, i.e., the letters, are causes of syllables, and in like manner earth is a cause of vases, and silver of a vial, and fire and such things, i.e., the simple bodies, are causes of bodies. And in the same way every part is a cause of the whole, and the propositions in a syllogism are a cause of the conclusion. And all of these things are understood as causes in the same way, namely, as that from which something comes to be is called a cause, for this is common to all the instances mentioned above.
Omnium autem nunc enumeratorum, quaedam se habent ut materia et quaedam ut forma, quae causat quidditatem rei: sicut omnes partes se habent ut materia, ut elementa syllabarum et quatuor elementa corporum mistorum; sed ea quae important totum vel compositionem vel quamcumque speciem, se habent in ratione formae; ut species referatur ad formas simplicium, totum autem et compositio ad formas compositorum. However, of all the things just enumerated some are causes as matter, and some as form, which causes the quiddity of the thing. Thus all parts, such as the elements of syllables, and the four elements of mixed bodies, are causes as matter. But those things which imply a whole or a composition or some species are understood as form. Thus species is referred to the forms of simple things, and the whole and composition are referred to the forms of composites.
Videntur autem hic esse duo dubia. 184. But there seems to be two difficulties here.
Primo quidem de hoc quod dicit, quod partes sunt causae materiales totius, cum supra partes definitionis reduxerit ad causam formalem.. The first is the fact that he says that the parts are material causes of the whole, whereas above [#179] he reduced the parts of the definition to the formal cause.
Et potest dici quod supra locutus est de partibus speciei, quae cadunt in definitione totius: hic autem loquitur de partibus materiae, in quarum definitione cadit totum, sicut circulus cadit in definitione semicirculi It can be said that he spoke above of the parts of the species which fall in the definition of the whole. But here he speaks of the parts of the matter in whose definition falls the whole. Thus circle falls in the definition of semicircle.
Sed melius dicendum est quod licet partes speciei quae ponuntur in definitione, comparentur ad suppositum naturae per modum causae formalis, tamen ad ipsam naturam cuius sunt partes, comparantur ut materia: nam omnes partes comparantur ad totum ut imperfectum ad perfectum, quae quidem est comparatio materiae ad formam. But it would be better to say that, although the parts of the species which are placed in the definition are related to the supposit of nature as a formal cause, they are, nevertheless, related to the very nature of which they are parts as matter. For all parts are related to the whole as the imperfect to the perfect, which is, indeed, the relation of matter to form.
Item potest esse dubium de hoc quod dicit, quod propositiones sunt materia conclusionis. Materia enim inest ei cuius est materia: unde supra notificans causam materialem, dixit quod est ex quo fit aliquid cum insit; propositiones autem sunt seorsum a conclusione. Further a difficulty can be raised with reference to what he says about propositions being the matter of conclusions. For matter is in that of which it is the matter. Hence speaking of the material cause above [#178] he said that it is that from which something comes to be when it is in it. But propositions are apart from the conclusion.
Sed dicendum quod ex terminis propositionum constituitur conclusio: unde secundum hoc propositiones dicuntur materia conclusionis, in quantum termini, qui sunt materia propositionum, sunt etiam materia conclusionis, licet non secundum quod stant sub ordine propositionum; sicut et farina dicitur materia panis, licet non secundum quod stat sub forma farinae. Ideo tamen potius dicuntur propositiones materia conclusionis quam e converso, quia termini qui coniunguntur in conclusione, separatim ponuntur in praemissis. Sic igitur habemus duos modos causae. But it must be pointed out that the conclusion is formed from the terms of the propositions. Hence in view of this the propositions are said to be the matter of the conclusion insofar as the terms which are the matter of the propositions are also the matter of the conclusion, although they are not in the same order as they are in the propositions. In this same way flour is called the matter of bread, but not insofar as it stands under the form of flour. And so propositions are better called the matter of the conclusion than conversely. For the terms which are joined in the conclusion are posited separately in the premises. Thus we have two modes of cause.
Quaedam vero dicuntur esse causae secundum aliam rationem, quia scilicet sunt principium motus et quietis. Et hoc modo semen, quod est activum in generatione, dicitur causa; et similiter medicus per hunc modum dicitur causa sanitatis; et consilians est causa per hunc modum, et omne faciens. 185. Some things are called causes for another reason, i.e., because they are a principle of motion and rest. And in this way the seed which is active in generation is called a cause. Likewise the doctor is called a cause of health according to this mode; so also the adviser is a cause according to this mode, and everyone who makes something.
Alia littera habet, et propositiones: nam propositiones quidem quantum ad terminos sunt materia conclusionis, ut dictum est; quantum autem ad vim illativam ipsarum reducuntur ad hoc genus causae; nam principium discursus rationis in conclusione est ex propositionibus. Another text has ‘and propositions’. For although propositions, insofar as their terms are concerned, are the matter of the conclusion, as was said above [#184], nevertheless insofar as their inferential power is concerned, they are reduced to this genus of cause. For the principle of the discourse of reason to its conclusion is from propositions.
In aliis vero causis invenitur alia ratio causae, secundum scilicet quod finis vel bonum habet rationem causae. Et haec species causae potissima est inter alias causas: est enim causa finalis aliarum causarum causa. Manifestum est enim quod agens agit propter finem; et similiter ostensum est supra in artificialibus, quod formae ordinantur ad usum sicut ad finem, et materiae in formas sicut in finem: et pro tanto dicitur finis causa causarum. 186. Another meaning of cause is found in other causes, i.e., insofar as the end or the good has the nature [ ratio ] of a cause. And this species of cause is the most powerful of all the causes, for the final cause is the cause of the other causes. It is clear that the agent acts for the sake of the end. And likewise it was shown above [L4 #173] in regard to artificial things that the form is ordered to use as to an end, and matter is ordered to form as to an end. And to this extent the end is called the cause of causes.
Et quia dixerat quod haec species causae habet rationem boni, et quandoque in his quae agunt per electionem contingit finem esse malum; ideo ad hanc dubitationem tollendam, dicit quod nihil differt utrum causa finalis sit vere bona vel apparens bona, quia quod apparet bonum non movet nisi sub ratione boni. Now since he has said that this species of cause has the nature of a good, while sometimes in those things which act by choice it happens that the end is evil, he forestalls this difficulty by saying that it makes no difference whether the final cause is a true or an apparent good. For what appears good does not move except under the aspect [ ratio ] of good.
Et sic ultimo concludit tot esse species causarum quot dictae sunt. And thus he finally concludes that the species of cause are as many as were mentioned.

Lectio 6 (195 a 28-b 30)
CONCERNING THE DIFFERENT MODES OF CAUSING
AND THOSE THINGS WHICH ARE CONSEQUENT UPON THESE DIFFERENT MODES OF CAUSING
Chapter 3 cont.
τρόποι δὲ τῶν αἰτίων ἀριθμῷ μὲν εἰσὶ πολλοί, κεφαλαιούμενοι δὲ καὶ οὗτοι ἐλάττους. λέγεται γὰρ αἴτια πολλαχῶς, καὶ αὐτῶν τῶν ὁμοειδῶν προτέρως καὶ ὑστέρως ἄλλο ἄλλου, οἷον ὑγιείας ἰατρὸς καὶ τεχνίτης, καὶ τοῦ διὰ πασῶν τὸ διπλάσιον καὶ ἀριθμός, καὶ ἀεὶ τὰ περιέχοντα πρὸς τὰ καθ' ἕκαστον. Now the modes of causation are many, though when brought under heads they too can be reduced in number. For 'cause' is used in many senses and even within the same kind one may be prior to another (e.g. the doctor and the expert are causes of health, the relation 2:1 and number of the octave), and always what is inclusive to what is particular.
ἔτι δ' ὡς τὸ συμβεβηκὸς καὶ τὰ τούτων γένη, οἷον ἀνδριάντος ἄλλως Πολύκλειτος καὶ ἄλλως ἀνδριαντοποιός, ὅτι συμβέβηκε τῷ ἀνδριαντοποιῷ τὸ Πολυκλείτῳ εἶναι. καὶ τὰ περιέχοντα δὲ τὸ συμβεβηκός, οἷον εἰ ὁ ἄνθρωπος αἴτιος εἴη ἀνδριάντος ἢ (195b.) ὅλως ζῷον. ἔστι δὲ καὶ τῶν συμβεβηκότων ἄλλα ἄλλων πορρώτερον καὶ ἐγγύτερον, οἷον εἰ ὁ λευκὸς καὶ ὁ μουσικὸς αἴτιος λέγοιτο τοῦ ἀνδριάντος. Another mode of causation is the incidental and its genera, e.g. in one way 'Polyclitus', in another 'sculptor' is the cause of a statue, because 'being Polyclitus' and 'sculptor' are incidentally conjoined. Also the classes in which the incidental attribute is included; thus 'a man' could be said to be the cause of a statue or, generally, 'a living creature'. An incidental attribute too may be more or less remote, e.g. suppose that 'a pale man' or 'a musical man' were said to be the cause of the statue.
πάντα δὲ καὶ τὰ οἰκείως λεγόμενα καὶ τὰ κατὰ συμβεβηκὸς τὰ μὲν ὡς δυνάμενα λέγεται τὰ δ' ὡς ἐνεργοῦντα, οἷον τοῦ οἰκοδομεῖσθαι οἰκίαν οἰκοδόμος ἢ οἰκοδομῶν οἰκοδόμος. ὁμοίως δὲ λεχθήσεται καὶ ἐφ' ὧν αἴτια τὰ αἴτια τοῖς εἰρημένοις, οἷον τουδὶ τοῦ ἀνδριάντος ἢ ἀνδριάντος ἢ ὅλως εἰκόνος, καὶ χαλκοῦ τοῦδε ἢ χαλκοῦ ἢ ὅλως ὕλης· καὶ ἐπὶ τῶν συμβεβηκότων ὡσαύτως. All causes, both proper and incidental, may be spoken of either as potential or as actual; e.g. the cause of a house being built is either 'house-builder' or 'house-builder building'. Similar distinctions can be made in the things of which the causes are causes, e.g. of 'this statue' or of 'statue' or of 'image' generally, of 'this bronze' or of 'bronze' or of 'material' generally. So too with the incidental attributes.
ἔτι δὲ συμπλεκόμενα καὶ ταῦτα κἀκεῖνα λεχθήσεται, οἷον οὐ Πολύκλειτος οὐδὲ ἀνδριαντοποιός, ἀλλὰ Πολύκλειτος ἀνδριαντοποιός. Again we may use a complex expression for either and say, e.g. neither 'Polyclitus' nor 'sculptor' but 'Polyclitus, sculptor'.
ἀλλ' ὅμως ἅπαντα ταῦτά ἐστι τὸ μὲν πλῆθος ἕξ, λεγόμενα δὲ διχῶς· ἢ γὰρ ὡς τὸ καθ' ἕκαστον, ἢ ὡς τὸ γένος, ἢ ὡς τὸ συμβεβηκός, ἢ ὡς τὸ γένος τοῦ συμβεβηκότος, ἢ ὡς συμπλεκόμενα ταῦτα ἢ ὡς ἁπλῶς λεγόμενα· πάντα δὲ ἢ ἐνεργοῦντα ἢ κατὰ δύναμιν. All these various uses, however, come to six in number, under each of which again the usage is twofold. Cause means either what is particular or a genus, or an incidental attribute or a genus of that, and these either as a complex or each by itself; and all six either as actual or as potential.
διαφέρει δὲ τοσοῦτον, ὅτι τὰ μὲν ἐνεργοῦντα καὶ τὰ καθ' ἕκαστον ἅμα ἔστι καὶ οὐκ ἔστι καὶ ὧν αἴτια, οἷον ὅδ' ὁ ἰατρεύων τῷδε τῷ ὑγιαζομένῳ καὶ ὅδε ὁ οἰκοδομῶν τῷδε τῷ οἰκοδομουμένῳ, τὰ δὲ κατὰ δύναμιν οὐκ ἀεί. φθείρεται γὰρ οὐχ ἅμα ἡ οἰκία καὶ ὁ οἰκοδόμος. The difference is this much, that causes which are actually at work and particular exist and cease to exist simultaneously with their effect, e.g. this healing person with this being-healed person and that house-building man with that being-built house; but this is not always true of potential causes—the house and the housebuilder do not pass away simultaneously.
δεῖ δ' ἀεὶ τὸ αἴτιον ἑκάστου τὸ ἀκρότατον ζητεῖν, ὥσπερ καὶ ἐπὶ τῶν ἄλλων (οἷον ἅνθρωπος οἰκοδομεῖ ὅτι οἰκοδόμος, ὁ δ' οἰκοδόμος κατὰ τὴν οἰκοδομικήν· τοῦτο τοίνυν πρότερον τὸ αἴτιον, καὶ οὕτως ἐπὶ πάντων)· In investigating the cause of each thing it is always necessary to seek what is most precise (as also in other things): thus man builds because he is a builder, and a builder builds in virtue of his art of building. This last cause then is prior: and so generally.
ἔτι τὰ μὲν γένη τῶν γενῶν, τὰ δὲ καθ' ἕκαστον τῶν καθ' ἕκαστον (οἷον ἀνδριαντοποιὸς μὲν ἀνδριάντος, ὁδὶ δὲ τουδί)· καὶ τὰς μὲν δυνάμεις τῶν δυνατῶν, τὰ δ' ἐνεργοῦντα πρὸς τὰ ἐνεργούμενα. ὅσα μὲν οὖν τὰ αἴτια καὶ ὃν τρόπον αἴτια, ἔστω ἡμῖν διωρισμένα ἱκανῶς. Further, generic effects should be assigned to generic causes, particular effects to particular causes, e.g. statue to sculptor, this statue to this sculptor; and powers are relative to possible effects, actually operating causes to things which are actually being effected. This must suffice for our account of the number of causes and the modes of causation.
Postquam philosophus distinxit species causarum, hic distinguit diversos modos causarum, etiam secundum eandem speciem causae. 187. After the Philosopher has distinguished the species of causes, he here distinguishes the various modes of causes in respect to the same species of cause.
Et circa hoc duo facit: primo distinguit diversos modos causarum; secundo determinat quaedam consequentia ad distinctionem praedictam, ibi: differunt autem et cetera. Concerning this he makes two points. First he distinguishes the different modes of causes. Secondly, where he says, ‘The difference is...’ (195 b 17 #195), he treats certain consequences of this distinction.
Circa primum duo facit: primo distinguit diversos modos causarum; secundo reducit eos ad certum numerum, ibi: sed tamen hae omnes et cetera. Concerning the first part he makes two points. First he distinguishes the different modes of causes, and secondly, where he says, ‘An these various...’ (195 b 13 #194), he reduces them to a certain number.
Circa primum distinguit modos causarum secundum quatuor divisiones. Concerning the first part he distinguishes the modes of causes according to four divisions.
Dicit ergo primo quod multi numero sunt modi causarum: sed si reducantur capitulatim, sive in quadam summa, ad aliqua communia, inveniuntur pauciores. Vel capitales accipiuntur secundum combinationem: manifestum est enim quod pauciores sunt combinationes modorum quam modi. He says, therefore, first that the modes of causes are numerous, but if they are reduced to headings, either under some highest, or under some common aspect, they are found to be fewer. Or ‘headings’ may be taken as a combination, for it is obvious that combinations of the modes are fewer than the modes.
Prima ergo divisio vel combinatio modorum est, quod in eadem specie causae dicitur una causa prior altera, ut intelligamus causam priorem universaliorem: ut sanitatis causa est medicus ut causa propria et posterior, artifex autem ut communior et prior; et hoc in specie causae efficientis. Et simile est in specie causae formalis: nam causa formalis diapason propria et posterior est proportio dupla; causa autem prior et communior est proportio numeralis, quae dicitur multiplicitas. Et similiter ea quae continet unamquamque causam communitate sui ambitus, dicitur causa prior. 188. Therefore the first division or combination of modes is that in the same species of cause one cause is said to be prior to another, as when we understand that the more universal cause is prior. Thus the doctor is the proper and posterior cause of health, whereas the artisan is the more common and prior cause. This is in the species of efficient cause. And the same thing is true in the species of formal cause. For the proper and posterior formal cause of the octave is the proportion of the double, whereas the more common and prior is the numerical proportion which is called multiplicity. And in like manner a cause which contains any cause in the community of its extension is a prior cause.
Advertendum est autem quod causa universalis et propria, vel prior et posterior, potest accipi aut secundum communitatem praedicationis, secundum exempla hic posita de medico et artifice; vel secundum communitatem causalitatis, ut si dicamus solem esse causam universalem calefactionis, ignem vero causam propriam: et haec duo sibi invicem correspondent. 189. It must be noted, however, that the universal cause and the proper cause, and the prior cause and the posterior cause, can be taken either according to a commonness in predication, as in the example given about the doctor and the artisan, or according to a commonness in causality, as if we say the sun is a universal cause of heating, whereas fire is a proper cause. And these two divisions correspond to each other.
Manifestum est enim quod quaelibet virtus extenditur ad aliqua secundum quod communicant in una ratione obiecti; et quanto ad plura extenditur, tanto oportet illam rationem esse communiorem: et cum virtus proportionetur obiecto secundum eius rationem, sequitur quod causa superior agat secundum formam magis universalem et minus contractam. Et sic est considerare in ordine rerum: quia quanto aliqua sunt superiora in entibus, tanto habent formas minus contractas, et magis dominantes supra materiam, quae coarctat virtutem formae. Unde et id quod est prius in causando, invenitur esse prius quodammodo secundum rationem universalioris praedicationis; ut puta, si ignis est primum calefaciens, caelum non tantum est primum calefaciens, sed primum alterans. For it is clear that any power extends to certain things insofar as they share in one nature [ ratio ], and the farther that that power extends, the more common that nature [ ratio ] must be. And since a power is proportioned to its object according to its nature [ ratio ], it follows that a higher cause acts according to a form which is more universal and less contracted. And this can be seen in the order of things. For to the extent that among beings some things are superior, to that extent they have forms which are less contracted and more dominant over matter, which contracts the power of form. And so that which is prior in causing is found to be prior in some way under the aspect [ ratio ] of a more universal predication. For example, if fire is the first in heating, then the heavens are not only the first in heating but also the first in producing alteration.
Secundam divisionem ponit ibi: amplius autem secundum accidens et cetera. 190. He gives the second division where he says, ‘Another mode of causation...’ (195 a 33).
Et dicit quod sicut causae per se dividuntur per causas priores et posteriores, vel communes et proprias, ita etiam et causae per accidens. He says that just as per se causes are divided into prior and posterior or common and proper, so also are per accidens causes.
Est enim praeter causas per se, accipere causas per accidens, et genera horum; sicut causa statuae per accidens quidem est Polycletus, per se autem causa statuae est faciens statuam: Polycletus enim est causa statuae inquantum accidit ei esse statuam facientem. Et etiam ea quae sua communitate continent Polycletum, sunt causa statuae per accidens, sicut et homo et animal. For besides per se causes there are per accidens causes and their genera. Thus Polycletus is. a per accidens cause of the statue, while the sculptor is a per se cause. For Polycletus is a cause of statue insofar as he happens to be a sculptor. And in like manner those things which contain Polycletus in their commonness, e.g., man and animal, are per accidens causes of statue.
Et iterum considerandum est quod in causis per accidens quaedam sunt propinquiores causis per se, et quaedam magis remotae. Nam causa per accidens dicitur omne illud quod coniungitur causae per se, quod non est de ratione eius; hoc autem contingit esse vel propinquius rationi causae, vel remotius ab ea; et secundum hoc causae per accidens erunt vel propinquiores vel remotiores: sicut, si statuam facienti accidat esse album et musicum, musicum propinquius est, quia est in eodem subiecto et secundum idem, scilicet secundum animam, in qua est musica et ars statuae factiva; album autem inest secundum corpus. Sed subiectum propinquius se habet adhuc quam alia accidentia, sicut Polycletus quam album vel musicum: non enim coniunguntur haec statuam facienti nisi propter subiectum. Moreover it must be noted that among per accidens causes some are closer to the per se causes and some are more removed. For everything which is joined to the per se cause but is not of its nature [ ratio ] is called a per accidens cause. Now a thing can be closer to the nature [ ratio ] of the [ per se ] cause or more removed from it, and to this extent the per accidens causes are closer or more removed. Thus, if a sculptor happens to be white and musical, the musical is closer, because it is in the same subject in respect to the same thing, i.e., in respect to the soul in which are both [the art of the] musician and the art of statue making. But the subject itself is still more closely related than the other accidents. Thus Polycletus is closer than white or musical, for these latter are not joined to this sculptor except through the subject.
Tertiam divisionem ponit ibi: praeter autem omnes et cetera. 191. He gives the third division where he says, ‘All causes...’ (195 b 4).
Et dicit quod praeter causas proprie dictas, idest per se, et per accidens, quaedam dicuntur causae in potentia, sicut potentes operari; quaedam vero sicut operantes in actu; sicut causa aedificandi domum potest dici vel aedificans in habitu vel aedificans in actu. He says that besides the causes properly so called, i.e., the causes per se and the causes per accidens, some things are said to be causes in potency, as being able to operate, while other things are actually operating causes. Thus either the builder in habit or the builder in act can be called the cause of the building of a house.
Et sicut distinguuntur causae modis praedictis, similiter distinguuntur ea quorum sunt causae. Est enim aliquid causatum posterius et magis proprium, et aliquid quod est prius et magis commune: sicut si dicatur quod aliquid est causa huius statuae vel statuae in communi; et adhuc communius si dicatur causa imaginis. Et similiter si dicatur aliquid causa motiva huius aeris, vel aeris in universali, vel materiae. 192. And just as causes are distinguished according to the above mentioned modes, so also the things of which they are the causes are distinguished. For one thing is caused posteriorly and more properly, and another priorly and more commonly. Thus something might be called the cause of this statue, or of statue in general, or still more commonly it might be called the cause of an image. And likewise something might be called the moving cause of this bronze, or of bronze in the universal, or of matter.
Et ita etiam potest dici in effectibus per accidens, et quod aliquid sit communius, et aliquid minus commune. Et dicitur effectus per accidens, quod coniungitur effectui per se et est praeter rationem eius: sicut per se effectus coqui est cibus delectabilis, per accidens autem cibus sanativus; medici autem e converso. So also, in per accidens effects, it can be said that one thing is more common and another less common. An effect is said to be per accidens when it is joined to a per se effect and is outside its nature [ ratio ]. Thus the per se effect of cooking is delectable food, but the per accidens effect is healthful food. However the converse is true of medicine.
Quartam divisionem ponit ibi: amplius autem complexae et cetera. 193. He gives the fourth division where he says, ‘Again we may use...’ (195 b 10).
Et dicit quod quandoque complexe accipiuntur causae per se cum causis per accidens; ut si non dicamus causam statuae Polycletum, qui est causa per accidens, neque facientem statuam, qui est causa per se, sed Polycletum statuam facientem. He says that sometimes per se causes are taken as a complex with per accidens causes, as when we say that neither Polycletus, who is a per accidens cause, nor the sculptor, who is the cause per se, is the cause of the statue, but rather that the sculptor Polycletus is the cause.
Deinde cum dicit: sed tamen hae omnes etc., reducit praedictos modos ad certum numerum. 194. Next where he says, ‘All these various uses...’ (195 b 13), he reduces the above mentioned modes to a certain number.
Et dicit quod praedicti modi certo numero sunt sex; sed quilibet eorum dupliciter dicitur. Sex autem modi sunt isti: singulare et genus, quod supra dixit prius et posterius; accidens et genus accidentis; simplex et complexum. Et quodlibet horum dividitur per potentiam et actum: et sic fiunt omnes modi duodecim. Distinguit autem omnes modos per potentiam et actum, quia quod est in potentia, non simpliciter est. He says that the above mentioned modes are six in number, but each of them is used in two ways. These are the six modes: the singular and the genus, which above [#188] he called the prior and the posterior, the accident and the genus of the accident, the simple and the complex. And each of these is divided by potency and act; and so all the modes become twelve. He distinguishes all the modes by potency and act because what is in potency is not simply.
Deinde cum dicit: differunt autem etc., determinat tria consequentia ad praedictam distinctionem modorum. 195. Next where he says, ‘The difference is...’ (195 b 17), he treats three things which follow from the distinction of modes just made.
Primum est, quod inter causas in actu et causas in potentia est ista differentia, quod causae operantes in actu simul sunt et non sunt cum eis quorum causae sunt in actu; ita tamen quod accipiantur causae singulares, idest propriae; sicut hic medicans simul est et non est cum hoc qui fit sanus, et hic aedificans cum hoc quod aedificatur. Si vero non acciperentur causae propriae, licet acciperentur in actu, non esset verum quod dicitur. Non enim aedificans est et non est simul cum hoc quod aedificatur: potest enim esse quod est aedificans in actu, sed tamen hoc aedificium non aedificatur, sed aliud. Sed si accipiamus aedificantem hoc aedificium, et hoc aedificium secundum quod est in aedificari, necesse est quod posito uno ponatur et alterum, et remoto uno removeatur et alterum. Hoc autem non accidit semper in causis quae sunt in potentia: non enim simul corrumpitur domus et homo qui aedificavit ipsam. The first point is that causes in act and causes in potency differ as follows. Causes operating in act exist and do not exist simultaneously with those things of which they are the causes in act. For example, if we take singular causes, i.e., proper causes, then this healer exists and does not exist simultaneously with him who becomes healed, and this builder exists simultaneously with that which is built. But this is not true if we take causes in act which are not proper causes. For it is not true that builder exists and does not exist simultaneously with that which is built. For it can happen that the builder is in act but this building is not being built, but some other. But if we take the one who is building this building, and if we take this building insofar as it is being built, then it is necessary that when one is posited, the other must be posited also, and when one is removed the other is removed. But this does not always happen in regard to causes which are in potency. For a home and the man who built it are not corrupted simultaneously.
Unde habetur quod sicut agentia inferiora, quae sunt causa rerum quantum ad suum fieri, oportet simul esse cum iis quae fiunt quandiu fiunt; ita agens divinum, quod est causa existendi in actu, simul est cum esse rei in actu. Unde subtracta divina actione a rebus, res in nihilum deciderent, sicut remota praesentia solis lumen in aere deficeret. And thus it follows that just as inferior agents, which are causes of the coining to be of things, must exist simultaneously with the things which come to be as long as they are coming to be, so also the divine agent, which is the cause of existing in act, is simultaneous with the existence of the thing in act. Hence if the divine action were removed from things, things would fall into nothingness, just as when the presence of the sun is removed, light ceases to be in the air.
Secundum ponit ibi: oportet autem semper etc.; dicens quod in naturalibus oportet semper supremam causam uniuscuiusque requirere, sicut contingit in artificialibus. Ut si quaeramus quare homo aedificat, respondetur, quia est aedificator; et similiter si quaeramus quare est aedificator, respondetur, quia habet artem aedificativam: et hic statur, quia haec est prima causa in hoc ordine. Et ideo oportet in rebus naturalibus procedere usque ad causam supremam. Et hoc ideo est, quia effectus nescitur nisi sciatur causa; unde si alicuius effectus causa sit etiam alterius causae effectus, sciri non poterit nisi causa eius sciatur; et sic quousque perveniatur ad primam causam. 196. He sets forth the second point where he says, ‘In investigating the cause...’ (195 b 21). He says that it is necessary to seek in natural things the first cause of each thing, just as we do in artificial things. So if we should ask why it is that a man builds, we answer ‘because he is a builder’. Likewise, if we ask why he is a builder, we answer, ‘because he possesses the builder’s art’. And here the inquiry stops, because this is the first cause in this order. Hence in natural things we should proceed to the first cause. This is so because the effect is not known unless the cause is known. Hence if the cause of an effect is also the effect of some other cause, then it cannot be known unless its cause is known, and so on until we arrive at a first cause.
Tertium ponit ibi: amplius autem aliae et cetera. Et est, quod causis debent proportionaliter respondere effectus, ita quod generalibus causis generales effectus reddantur, et singularibus singulares; puta, si dicatur quod statuae causa est statuam faciens, et huius statuae hic statuam faciens. Et similiter causis in potentia respondent effectus in potentia, et causis in actu effectus in actu. 197. He sets forth the third point where he says, ‘Further generic effects...’ (195 b 25). Effects should correspond proportionally to causes so that general effects be referred to general causes and singular effects to singular causes. For example, if it is said that the cause of statue is sculptor, then the cause of this statue is this sculptor. In like manner effects in potency should correspond to causes in potency and effects in act to causes in act.
Et ultimo epilogando concludit quod sufficienter determinatum est de speciebus et modis causarum. And finally in summary he concludes that this is a sufficient treatment of the species and modes of causes.

Lectio 7 (195 b 31-196 b 9)
DIFFERENT OPINIONS ABOUT FORTUNE AND CHANCE, THE HIDDEN CAUSES
Chapter 4
Λέγεται δὲ καὶ ἡ τύχη καὶ τὸ αὐτόματον τῶν αἰτίων, καὶ πολλὰ καὶ εἶναι καὶ γίγνεσθαι διὰ τύχην καὶ διὰ τὸ αὐτόματον· τίνα οὖν τρόπον ἐν τούτοις ἐστὶ τοῖς αἰτίοις ἡ τύχη καὶ τὸ αὐτόματον, καὶ πότερον τὸ αὐτὸ ἡ τύχη καὶ τὸ αὐτόματον ἢ ἕτερον, καὶ ὅλως τί ἐστιν ἡ τύχη καὶ τὸ αὐτόματον, ἐπισκεπτέον. But chance also and spontaneity are reckoned among causes: many things are said both to be and to come to be as a result of chance and spontaneity. We must inquire therefore in what manner chance and spontaneity are present among the causes enumerated, and whether they are the same or different, and generally what chance and spontaneity are.
ἔνιοι γὰρ καὶ εἰ ἔστιν ἢ μὴ ἀποροῦσιν· (196a.) οὐδὲν γὰρ δὴ γίγνεσθαι ἀπὸ τύχης φασίν, ἀλλὰ πάντων εἶναί τι αἴτιον ὡρισμένον ὅσα λέγομεν ἀπὸ ταὐτομάτου γίγνεσθαι ἢ τύχης, οἷον τοῦ ἐλθεῖν ἀπὸ τύχης εἰς τὴν ἀγοράν, καὶ καταλαβεῖν ὃν ἐβούλετο μὲν οὐκ ᾤετο δέ, αἴτιον τὸ βούλεσθαι ἀγοράσαι ἐλθόντα· ὁμοίως δὲ καὶ ἐπὶ τῶν ἄλλων τῶν ἀπὸ τύχης λεγομένων ἀεί τι εἶναι λαβεῖν τὸ αἴτιον, ἀλλ' οὐ τύχην, Some people even question whether they are real or not. They say that nothing happens by chance, but that everything which we ascribe to chance or spontaneity has some definite cause, e.g. coming 'by chance' into the market and finding there a man whom one wanted but did not expect to meet is due to one's wish to go and buy in the market. Similarly in other cases of chance it is always possible, they maintain, to find something which is the cause; but not chance,
ἐπεὶ εἴ γέ τι ἦν ἡ τύχη, ἄτοπον ἂν φανείη ὡς ἀληθῶς, καὶ ἀπορήσειεν ἄν τις διὰ τί ποτ' οὐδεὶς τῶν ἀρχαίων σοφῶν τὰ αἴτια περὶ γενέσεως καὶ φθορᾶς λέγων περὶ τύχης οὐδὲν διώρισεν, ἀλλ' ὡς ἔοικεν, οὐδὲν ᾤοντο οὐδ' ἐκεῖνοι εἶναι ἀπὸ τύχης. for if chance were real, it would seem strange indeed, and the question might be raised, why on earth none of the wise men of old in speaking of the causes of generation and decay took account of chance; whence it would seem that they too did not believe that anything is by chance.
ἀλλὰ καὶ τοῦτο θαυμαστόν· πολλὰ γὰρ καὶ γίγνεται καὶ ἔστιν ἀπὸ τύχης καὶ ἀπὸ ταὐτομάτου, ἃ οὐκ ἀγνοοῦντες ὅτι ἔστιν ἐπανενεγκεῖν ἕκαστον ἐπί τι αἴτιον τῶν γιγνομένων, καθάπερ ὁ παλαιὸς λόγος εἶπεν ὁ ἀναιρῶν τὴν τύχην, ὅμως τούτων τὰ μὲν εἶναί φασι πάντες ἀπὸ τύχης τὰ δ' οὐκ ἀπὸ τύχης· διὸ καὶ ἁμῶς γέ πως ἦν ποιητέον αὐτοῖς μνείαν. ἀλλὰ μὴν οὐδ' ἐκείνων γέ τι ᾤοντο εἶναι τὴν τύχην, οἷον φιλίαν ἢ νεῖκος ἢ νοῦν ἢ πῦρ ἢ ἄλλο γέ τι τῶν τοιούτων. But there is a further circumstance that is surprising. Many things both come to be and are by chance and spontaneity, and although know that each of them can be ascribed to some cause (as the old argument said which denied chance), nevertheless they speak of some of these things as happening by chance and others not. For this reason also they ought to have at least referred to the matter in some way or other. Certainly the early physicists found no place for chance among the causes which they recognized—love, strife, mind, fire, or the like.
ἄτοπον οὖν εἴτε μὴ ὑπελάμβανον εἶναι εἴτε οἰόμενοι παρέλειπον, καὶ ταῦτ' ἐνίοτε χρώμενοι, ὥσπερ Ἐμπεδοκλῆς οὐκ ἀεὶ τὸν ἀέρα ἀνωτάτω ἀποκρίνεσθαί φησιν, ἀλλ' ὅπως ἂν τύχῃ. λέγει γοῦν ἐν τῇ κοσμοποιίᾳ ὡς "οὕτω συνέκυρσε θέων τοτέ, πολλάκι δ' ἄλλως"· καὶ τὰ μόρια τῶν ζῴων ἀπὸ τύχης γενέσθαι τὰ πλεῖστά φησιν. This is strange, whether they supposed that there is no such thing as chance or whether they thought there is but omitted to mention it—and that too when they sometimes used it, as Empedocles does when he says that the air is not always separated into the highest region, but 'as it may chance'. At any rate he says in his cosmogony that 'it happened to run that way at that time, but it often ran otherwise.' He tells us also that most of the parts of animals came to be by chance.
εἰσὶ δέ τινες οἳ καὶ τοὐρανοῦ τοῦδε καὶ τῶν κόσμων πάντων αἰτιῶνται τὸ αὐτόματον· ἀπὸ ταὐτομάτου γὰρ γενέσθαι τὴν δίνην καὶ τὴν κίνησιν τὴν διακρίνασαν καὶ καταστήσασαν εἰς ταύτην τὴν τάξιν τὸ πᾶν. There are some too who ascribe this heavenly sphere and all the worlds to spontaneity. They say that the vortex arose spontaneously, i.e. the motion that separated and arranged in its present order all that exists.
καὶ μάλα τοῦτό γε αὐτὸ θαυμάσαι ἄξιον· λέγοντες γὰρ τὰ μὲν ζῷα καὶ τὰ φυτὰ ἀπὸ τύχης μήτε εἶναι μήτε γίγνεσθαι, ἀλλ' ἤτοι φύσιν ἢ νοῦν ἤ τι τοιοῦτον ἕτερον εἶναι τὸ αἴτιον (οὐ γὰρ ὅ τι ἔτυχεν ἐκ τοῦ σπέρματος ἑκάστου γίγνεται, ἀλλ' ἐκ μὲν τοῦ τοιουδὶ ἐλαία ἐκ δὲ τοῦ τοιουδὶ ἄνθρωπος), τὸν δ' οὐρανὸν καὶ τὰ θειότατα τῶν φανερῶν ἀπὸ τοῦ αὐτομάτου γενέσθαι, τοιαύτην δ' αἰτίαν μηδεμίαν εἶναι οἵαν τῶν ζῴων καὶ τῶν φυτῶν. καίτοι εἰ οὕτως ἔχει, τοῦτ' αὐτὸ ἄξιον ἐπιστάσεως, καὶ καλῶς ἔχει λεχθῆναί (196b.) τι περὶ αὐτοῦ. This statement might well cause surprise. For they are asserting that chance is not responsible for the existence or generation of animals and plants, nature or mind or something of the kind being the cause of them (for it is not any chance thing that comes from a given seed but an olive from one kind and a man from another); and yet at the same time they assert that the heavenly sphere and the divinest of visible things arose spontaneously, having no such cause as is assigned to animals and plants. Yet if this is so, it is a fact which deserves to be dwelt upon, and something might well have been said about it.
πρὸς γὰρ τῷ καὶ ἄλλως ἄτοπον εἶναι τὸ λεγόμενον, ἔτι ἀτοπώτερον τὸ λέγειν ταῦτα ὁρῶντας ἐν μὲν τῷ οὐρανῷ οὐδὲν ἀπὸ ταὐτομάτου γιγνόμενον, ἐν δὲ τοῖς οὐκ ἀπὸ τύχης πολλὰ συμβαίνοντα ἀπὸ τύχης· καίτοι εἰκός γε ἦν τοὐναντίον γίγνεσθαι. For besides the other absurdities of the statement, it is the more absurd that people should make it when they see nothing coming to be spontaneously in the heavens, but much happening by chance among the things which as they say are not due to chance; whereas we should have expected exactly the opposite.
εἰσὶ δέ τινες οἷς δοκεῖ εἶναι μὲν αἰτία ἡ τύχη, ἄδηλος δὲ ἀνθρωπίνῃ διανοίᾳ ὡς θεῖόν τι οὖσα καὶ δαιμονιώτερον. ὥστε σκεπτέον καὶ τί ἑκάτερον, καὶ εἰ ταὐτὸν ἢ ἕτερον τό τε αὐτόματον καὶ ἡ τύχη, καὶ πῶς εἰς τὰ διωρισμένα αἴτια ἐμπίπτουσιν. Others there are who, indeed, believe that chance is a cause, but that it is inscrutable to human intelligence, as being a divine thing and full of mystery. Thus we must inquire what chance and spontaneity are, whether they are the same or different, and how they fit into our division of causes.
Postquam philosophus determinavit de manifestis speciebus et modis causarum, hic determinat de quibusdam modis immanifestis, scilicet de fortuna et casu. 198. Having treated the obvious species and modes of cause, the Philosopher here takes up certain hidden modes, namely, fortune and chance.
Concerning this he makes two points. First he states his intention. Secondly, he pursues his intention, where he says, ‘Some people even question...’(195 b 36 #198)
Et circa hoc duo facit: primo dicit de quo est intentio; secundo prosequitur propositum, ibi: quidam enim si sint et cetera. He says, therefore, first that fortune and chance are also reckoned among the causes, since many things are said to come to be or to exist because of fortune and chance.
Dicit ergo primo quod etiam fortuna et casus computantur inter causas, cum multa dicantur fieri vel esse etiam propter fortunam et casum. Et ideo tria consideranda sunt de eis: scilicet, quomodo reducantur ad causas praedictas; et iterum utrum fortuna et casus sint idem, vel aliud et aliud; et iterum quid sit casus et fortuna. And so with respect to fortune and chance three things must be considered; namely, how they are reduced to the causes mentioned above, then whether fortune and chance are the same or different, and finally what chance and fortune are.
Deinde cum dicit: quidam enim si sint etc., incipit de fortuna et casu determinare: Next where he says, ‘Some people even question...’ (195 b 36), he begins his treatment of fortune and chance.
et primo ponit opiniones aliorum; secundo determinat veritatem, ibi: primum quidem igitur quoniam et cetera. First he sets forth the opinions of others. Secondly, where he says, ‘First then we observe...’ (196 b 10; L8 #207), he establishes the truth.
Circa primum ponit tres opiniones: secunda incipit, ibi: sunt autem quidam qui caeli huius etc.; tertia ibi: sunt autem quidam quibus videtur et cetera. Concerning the first part he sets forth three opinions. The second begins where he says, ‘There are some...’(196 a 25 #203), and the third, where he says, ‘Others there are...’ (196 b 5 #206).
Circa primum duo facit: primo ponit opinionem negantium fortunam et casum, et rationes eorum; secundo disputat de altera rationum, ibi: sed hoc mirabile et cetera. Concerning the first part he makes two points. First he sets forth the opinions and arguments of those who deny fortune and chance. Secondly, where he says, ‘But there is a further circumstance...’(196 a 11 #201), he argues about some of these reasons.
Dicit ergo primo, quod quidam dubitaverunt an fortuna et casus essent: et negaverunt ea esse duabus rationibus. 199. He says, therefore, first that some have questioned whether fortune and chance exist. They deny that they exist for two reasons.
Quarum prima est, quia omnia ista quae dicuntur fieri a casu vel fortuna, inveniuntur habere aliquam causam determinatam, aliam a fortuna. Et ponit huiusmodi exemplum: si enim aliquis veniens ad forum, inveniat aliquem hominem quem volebat invenire, de quo tamen non opinabatur ante quod esset eum inventurus, dicimus quod inventio illius hominis sit a fortuna: sed huius inventionis causa est voluntas emendi, propter quam ivit ad forum, ubi erat ille quem invenit. Et similiter est in omnibus aliis quae dicuntur esse a fortuna; quia habent aliquam aliam causam praeter fortunam. Et sic fortuna non videtur esse causa alicuius, et per consequens nec aliquid esse: quia non ponimus fortunam nisi inquantum aliqua ponimus esse a fortuna. The first argument is that all of those things which are said to come to be by chance or fortune are found to have some determinate cause other than fortune. He gives an example of this sort of thing. If someone coming to the market place should find some man whom he wished to find, but who he did not previously believe would be found, we say that his finding of this man was due to fortune. But the cause of this finding is his will to buy, for the sake of which he went to the market where the man whom he sought was. And the same is true of all other things which are said to be by fortune, for they have some cause other than fortune. And so fortune does not seem to be a cause of anything, and consequently is nothing. For we do not posit fortune except insofar as we hold that some things exist by fortune.
Secundam rationem ponit ibi: quoniam si aliquid et cetera. 200. He gives the second argument where he says, for if chance were real...’ (196 a 6).
Et dicit quod si fortuna aliquid esset, inconveniens videretur (sicut vere est inconveniens, ut infra ostendetur) et dubitationem afferens, quare nullus antiquorum sapientum qui determinaverunt de causis generationis et corruptionis, aliquid determinavit de fortuna: sed, sicut videtur, nihil opinabantur illi antiqui esse a fortuna. Et sic haec secunda ratio sumitur ex opinione antiquorum naturalium. He says that if fortune were something, it seems to be inconsistent (and that it is truly inconsistent is shown below #201) and puzzling why none of the ancient wise men who treated the causes of generation and corruption treated fortune. But, as it seems, those ancients thought that nothing exists by fortune. This second argument is taken from the opinion of the ancient natural philosophers.
Deinde cum dicit: sed hoc mirabile etc., disputat de hac secunda ratione, ostendens quod supra supposuerat, scilicet quod inconveniens sit antiquos naturales non determinasse de casu et fortuna: et hoc probat duabus rationibus. 201. Next where he says, ‘But there is a further circumstance...’ (196 a 11), he argues about this second proof, showing what he had assumed above, namely, that it is inconsistent that the ancient natural philosophers did not treat chance and fortune. He proves this with two arguments.
Quarum primam ponit dicens: et mirabile videtur, sicut et vere est, quod antiqui naturales de casu et fortuna non determinaverunt. Assumpserunt enim sibi determinare causas eorum quae fiunt; multa autem sunt quae fiunt a fortuna et casu; unde de fortuna et casu determinare debuerunt. Nec excusantur propter rationem supra dictam destruentem fortunam et casum: quia licet homines non ignorarent quod contingit reducere unumquemque effectum in aliquam causam, sicut dixit praedicta opinio destruens fortunam et casum, nihilominus tamen posuerunt, non obstante hac ratione, quaedam fieri a fortuna et quaedam non. Unde ipsis philosophis naturalibus facienda erat mentio de fortuna et casu, saltem ut ostenderent falsum esse aliqua fieri a fortuna et casu; et ut assignarent rationem quare quaedam dicebantur esse a fortuna et quaedam non. Nec etiam possunt excusari per hoc quod casus et fortuna reducerentur in aliquam causarum ab eis positarum: non enim opinabantur quod fortuna sit aliquid eorum quae arbitrabantur esse causas, ut amicitiam aut litem aut aliquid huiusmodi. His first argument is as follows. It seems remarkable, and indeed it is, that the ancient natural philosophers did not treat chance and fortune. For they assumed that they treated the causes of those things which come to be, yet there are many things which come to be by fortune and chance. Hence they should have treated fortune and chance. Nor are they to be excused by the argument given above [200] which denies fortune and chance. For although men know that every effect is reduced to some cause, as the above opinion which denies fortune and chance stated, nevertheless, regardless of this argument, these philosophers held that some things come to be by fortune, and other things do not. Hence these natural philosophers must make mention of fortune and chance at least in order to show that it is false that some things come to be by fortune and chance, and in order to point out the reason why some things are said to be by fortune and some not. Nor can they be excused by reason of the fact that chance and fortune would be reduced to one of the causes which they posited. For they did not think that fortune is one of the things which they thought to be causes, such as friendship or strife or some other such thing.
Secundam rationem ponit ibi: inconveniens igitur est et cetera. 202. He gives his second argument where he says, ‘This is strange...’ (196 a 19).
Et dicit quod inconveniens est quod antiqui naturales reliquerunt tractare de fortuna, sive putaverunt fortunam esse sive non: quia si putaverunt fortunam esse, inconveniens fuit quod de ea non determinaverunt; si vero non putaverunt fortunam esse, inconveniens fuit quod ea aliquando usi sunt; sicut Empedocles, qui dixit quod aer non semper adunatur superius supra terram quasi hoc ei sit naturale, sed quia ita accidit a casu. Dicit enim quod quando mundus est factus, lite distinguente elementa, accidit quod aer se collegit in istum locum, et sicut tunc cucurrit, ita semper stante isto mundo cursum habebit: sed multoties in aliis mundis, quos ponebat infinities fieri et corrumpi, ut supra dictum est, aer aliter ordinatur inter partes universi. Et similiter dicebat quod plurimae partes animalium fiunt a fortuna; sicut quod in prima constitutione mundi fiebant capita sine cervice. He says that whether they thought that fortune existed or not, it is inconsistent that the ancient natural philosophers neglected to treat fortune. For if they thought that there was fortune, it is inconsistent that they did not treat it; if, however, they thought that there was no fortune, it is inconsistent that they sometimes used it. For example, Empedocles said that air is not always united on high above the earth, as if this were natural to it, but rather this happens by chance. For he says that when the earth was made by strife distinguishing the elements, it happened that air gathered together in this place, and as it came together then, it will hold this course so long as the world remains. But in other worlds, which he held come to be and are corrupted to infinity, as was said above [I, L10 #76], air would be differently related in many ways to the parts of the universe. And likewise he said that the many parts of animals come to be by fortune, so that in the first production of the world, heads came to be without necks.
Deinde cum dicit: sunt autem quidam etc., ponit secundam opinionem. 203. Next where he says, ‘These are some...’ (196 a 25), he gives the second opinion.
Et circa hoc duo facit: primo ponit eam; secundo improbat eam, ibi: et multum hoc et cetera. Concerning this he makes two points. First he sets forth the opinion. Secondly, he disproves it where he says, ‘This statement might...’ (196 a 28 #204).
Dicit ergo primo quod quidam dixerunt casum esse causam caeli et omnium partium mundi; et dicebant quod revolutio mundi, et motus stellarum distinguens et statuens totum universum inferius secundum hunc ordinem, sit a casu. Et haec videtur esse opinio Democriti, dicentis quod ex concursu atomorum per se mobilium, caelum et totus mundus casualiter constitutus est. He says, therefore first, that some have said that chance is the cause of the heavens and all the parts of the world. And they said that the revolution of the world, and the movement of the stars distinguishing and constituting the whole universe below according to this order, is by chance. This seems to be the opinion of Democritus, who says that the heavens and the whole world are constituted by chance through the movement of atoms which are per se mobile.
Deinde cum dicit: et multum hoc admiratione etc., improbat hanc positionem duabus rationibus. 204. Next where he says, ‘This statement might...’ (196 a 28), he disproves this position with two arguments.
Quarum prima est quod admiratione dignum videtur quod animalia et plantae non fiunt a fortuna, sed ab intellectu vel natura, vel a quacumque alia causa determinata: quod ex hoc patet quod non ex quocumque semine aliquid generatur, sed ex determinato semine fit homo, et ex determinato semine oliva. Et cum ista inferiora non fiant a fortuna, dignum est admiratione quod caelum et ea quae sunt diviniora inter sensibilia manifesta nobis, scilicet partes mundi sempiternae, sint a casu, et non habeant aliquam causam determinatam, sicut animalia et plantae. Et si hoc verum est, dignum fuisset insistere, et assignare rationem quare sic esset: quod tamen antiqui praetermiserunt. The first argument is that it would seem to be worthy of great wonder that animals and plants are not from fortune but from intellect or nature or some other determinate cause. For it is clear that a thing is not generated from any seed whatsoever, but man from a determinate seed, and the olive from a determinate seed. And since these inferior things do not come to be by fortune, it is worthy of wonder that the heavens and those things which are more divine among the sensible things obvious to us, e.g. the sempiternal parts of the world, are by chance, and should not have any determinate cause, as do animals and plants. And if this is true, it would have been worthwhile to insist and to give a reason why this is so. But the ancients failed to do this.
Secundam rationem ponit, ibi: quomodo enim eo quod aliter etc., dicens: quomodo potest esse verum quod caelestia corpora sint a casu, et inferiora non: cum et aliter videatur esse inconveniens, ex hoc ipso quod illa nobiliora sunt; et adhuc etiam inconvenientius secundum ea quae videntur? Videmus enim quod in caelo nihil fit a casu; in his autem inferioribus, quae non dicuntur esse a casu, multa videntur contingere a fortuna. Rationabile autem esset e converso accidere secundum eorum positionem; ut scilicet in illis invenirentur aliqua fieri a casu vel a fortuna, quorum casus vel fortuna est causa; non autem in illis quorum non est causa. 205. He gives the second argument where he says, ‘For besides the other...’ (196 b 1). How can it be true that the celestial bodies are by chance, while inferior bodies are not? This seems to be inconsistent first from the fact that they are the nobler, and secondly it is even more inconsistent in the light of what is seen. For we see that in the heavens nothing comes to be by chance, whereas in inferior bodies, which are not said to be by chance, many things seem to happen by fortune. According to their position it would be more reasonable if the converse were true, so that in those things whose cause is chance or fortune, some things would be found to come to be by chance or by fortune, whereas in those things whose cause is not chance or fortune, these latter would not be found.
Deinde cum dicit: sunt autem quidam, etc., ponit tertiam opinionem de fortuna. 206. Next where he says, ‘Others there are...’ (196 b 5), he sets forth the third opinion about fortune.
Et dicit quod quibusdam videtur quod fortuna sit causa, sed immanifesta intellectui humano, ac si sit quoddam divinum et supra homines. Volebant enim quod omnes fortuiti eventus reducerentur in aliquam divinam causam ordinantem, sicut nos ponimus omnia ordinari per divinam providentiam. He says that it seems to some that fortune is a cause, but it is hidden to the human intellect, as if it were something divine and above men. For they wanted to hold the position that all fortuitous events are reduced to some divine ordaining cause, as we hold that all things are ordered by divine providence.
Sed quamvis haec opinio habeat veram radicem, non tamen bene usi sunt nomine fortunae. Illud enim divinum ordinans non potest dici vel nominari fortuna; quia secundum quod aliquid participat rationem vel ordinem, recedit a ratione fortunae. Unde magis debet dici fortuna causa inferior, quae de se non habet ordinem ad eventum fortuitum, quam causa superior, si qua sit ordinans. But although this opinion has a radical truth, they did not use the name ‘fortune’ well. For that divine thing which orders cannot be called or named fortune, because to the extent that a thing participates in reason or order, it recedes from the nature [ ratio ] of fortune. Hence, the inferior cause, which of itself does not have an ordination to the fortuitous event, should much more be called fortune than the superior cause, if such a cause is the one which orders.
Praetermittit tamen inquisitionem huius opinionis, tum quia excedit metas scientiae naturalis, tum quia infra manifestat quod fortuna non est causa per se, sed per accidens. Unde per ea quae sequuntur, quomodo se habeat de his opinionibus magis erit manifestum. Et ideo concludit quod ad evidentiam harum opinionum considerandum est quid sit fortuna et casus; et utrum sint idem vel aliud; et quomodo reducantur ad causas praedictas. He omits an inquiry about this opinion, both because it exceeds the bounds of natural science, and because he shows below [L8 #214] that fortune is not a per se cause, but a per accidens cause. Hence how he evaluates these opinions will be made more clear in what follows. And so he concludes that for the clarification of these opinions, we must consider what fortune and chance are, and whether they are the same or different, and how they are reduced to the causes mentioned above.

Lectio 8 (196 b 10-197 a 7)
AFTER MAKING CERTAIN DIVISIONS AMONG EFFECTS AND CAUSES,
HE CONCLUDES TO A DEFINITION OF FORTUNE
Chapter 5
Πρῶτον μὲν οὖν, ἐπειδὴ ὁρῶμεν τὰ μὲν ἀεὶ ὡσαύτως γιγνόμενα τὰ δὲ ὡς ἐπὶ τὸ πολύ, φανερὸν ὅτι οὐδετέρου τούτων αἰτία ἡ τύχη λέγεται οὐδὲ τὸ ἀπὸ τύχης, οὔτε τοῦ ἐξ ἀνάγκης καὶ αἰεὶ οὔτε τοῦ ὡς ἐπὶ τὸ πολύ. ἀλλ' ἐπειδὴ ἔστιν ἃ γίγνεται καὶ παρὰ ταῦτα, καὶ ταῦτα πάντες φασὶν εἶναι ἀπὸ τύχης, φανερὸν ὅτι ἔστι τι ἡ τύχη καὶ τὸ αὐτόματον· τά τε γὰρ τοιαῦτα ἀπὸ τύχης καὶ τὰ ἀπὸ τύχης τοιαῦτα ὄντα ἴσμεν. First then we observe that some things always come to pass in the same way, and others for the most part. It is clearly of neither of these that chance is said to be the cause, nor can the 'effect of chance' be identified with any of the things that come to pass by necessity and always, or for the most part. But as there is a third class of events besides these two—events which all say are 'by chance'—it is plain that there is such a thing as chance and spontaneity; for we know that things of this kind are due to chance and that things due to chance are of this kind.
τῶν δὲ γιγνομένων τὰ μὲν ἕνεκά του γίγνεται τὰ δ' οὔ But, secondly, some events are for the sake of something, others not.
(τούτων δὲ τὰ μὲν κατὰ προαίρεσιν, τὰ δ' οὐ κατὰ προαίρεσιν, ἄμφω δ' ἐν τοῖς ἕνεκά του), ὥστε δῆλον ὅτι καὶ ἐν τοῖς παρὰ τὸ ἀναγκαῖον καὶ τὸ ὡς ἐπὶ τὸ πολὺ ἔστιν ἔνια περὶ ἃ ἐνδέχεται ὑπάρχειν τὸ ἕνεκά του. ἔστι δ' ἕνεκά του ὅσα τε ἀπὸ διανοίας ἂν πραχθείη καὶ ὅσα ἀπὸ φύσεως. Again, some of the former class are in accordance with deliberate intention, others not, but both are in the class of things which are for the sake of something. Hence it is clear that even among the things which are outside the necessary and the normal, there are some in connexion with which the phrase 'for the sake of something' is applicable. (Events that are for the sake of something include whatever may be done as a result of thought or of nature.)
τὰ δὴ τοιαῦτα ὅταν κατὰ συμβεβηκὸς γένηται, ἀπὸ τύχης φαμὲν εἶναι (ὥσπερ γὰρ καὶ ὄν ἐστι τὸ μὲν καθ' αὑτὸ τὸ δὲ κατὰ συμβεβηκός, οὕτω καὶ αἴτιον ἐνδέχεται εἶναι, οἷον οἰκίας καθ' αὑτὸ μὲν αἴτιον τὸ οἰκοδομικόν, κατὰ συμβεβηκὸς δὲ τὸ λευκὸν ἢ τὸ μουσικόν· τὸ μὲν οὖν καθ' αὑτὸ αἴτιον ὡρισμένον, τὸ δὲ κατὰ συμβεβηκὸς ἀόριστον· ἄπειρα γὰρ ἂν τῷ ἑνὶ συμβαίη). Things of this kind, then, when they come to pass incidental are said to be 'by chance'. For just as a thing is something either in virtue of itself or incidentally, so may it be a cause. For instance, the housebuilding faculty is in virtue of itself the cause of a house, whereas the pale or the musical is the incidental cause. That which is per se cause of the effect is determinate, but the incidental cause is indeterminable, for the possible attributes of an individual are innumerable.
καθάπερ οὖν ἐλέχθη, ὅταν ἐν τοῖς ἕνεκά του γιγνομένοις τοῦτο γένηται, τότε λέγεται ἀπὸ ταὐ τομάτου καὶ ἀπὸ τύχης (αὐτῶν δὲ πρὸς ἄλληλα τὴν διαφορὰν τούτων ὕστερον διοριστέον· νῦν δὲ τοῦτο ἔστω φανερόν, ὅτι ἄμφω ἐν τοῖς ἕνεκά τού ἐστιν)· οἷον ἕνεκα τοῦ ἀπολαβεῖν τὸ ἀργύριον ἦλθεν ἂν κομιζομένου τὸν ἔρανον, εἰ ᾔδει· ἦλθε δ' οὐ τούτου ἕνεκα, ἀλλὰ συνέβη αὐτῷ ἐλθεῖν, καὶ ποιῆσαι τοῦτο τοῦ κομίσασθαι ἕνεκα· τοῦτο δὲ οὔθ' ὡς ἐπὶ τὸ πολὺ φοιτῶν εἰς τὸ (197a.) χωρίον οὔτ' ἐξ ἀνάγκης· ἔστι δὲ τὸ τέλος, ἡ κομιδή, οὐ τῶν ἐν αὐτῷ αἰτίων, ἀλλὰ τῶν προαιρετῶν καὶ ἀπὸ διανοίας· καὶ λέγεταί γε τότε ἀπὸ τύχης ἐλθεῖν, εἰ δὲ προελόμενος καὶ τούτου ἕνεκα ἢ ἀεὶ φοιτῶν ἢ ὡς ἐπὶ τὸ πολύ [κομιζόμενος], οὐκ ἀπὸ τύχης. To resume then; when a thing of this kind comes to pass among events which are for the sake of something, it is said to be spontaneous or by chance. (The distinction between the two must be made later—for the present it is sufficient if it is plain that both are in the sphere of things done for the sake of something.) Example: A man is engaged in collecting subscriptions for a feast. He would have gone to such and such a place for the purpose of getting the money, if he had known. He actually went there for another purpose and it was only incidentally that he got his money by going there; and this was not due to the fact that he went there as a rule or necessarily, nor is the end effected (getting the money) a cause present in himself—it belongs to the class of things that are intentional and the result of intelligent deliberation. It is when these conditions are satisfied that the man is said to have gone 'by chance'. If he had gone of deliberate purpose and for the sake of this—if he always or normally went there when he was collecting payments—he would not be said to have gone 'by chance'.
δῆλον ἄρα ὅτι ἡ τύχη αἰτία κατὰ συμβεβηκὸς ἐν τοῖς κατὰ προαίρεσιν τῶν ἕνεκά του. διὸ περὶ τὸ αὐτὸ διάνοια καὶ τύχη· ἡ γὰρ προαίρεσις οὐκ ἄνευ διανοίας. It is clear then that chance is an incidental cause in the sphere of those actions for the sake of something which involve purpose. Intelligent reflection, then, and chance are in the same sphere, for purpose implies intelligent reflection.
Postquam philosophus posuit opiniones aliorum de fortuna et casu, hic determinat veritatem. 207. Having set forth the opinions of others about fortune and chance, the Philosopher here determines the truth.
Et dividitur in partes tres: in prima ostendit quid sit fortuna; in secunda in quo differant casus et fortuna, ibi: differunt autem etc.; in tertia ostendit ad quod genus causae casus et fortuna reducantur, ibi: sed modorum causarum et cetera. This section is divided into three parts. First he shows what fortune is. Secondly, where he says, ‘They differ...’ (197 a 36; L10 #226), he shows how fortune and chance differ. Thirdly, where he says, ‘Both belong to...’ (198 a 2; L10 #236), he points out the genus of cause to which chance and fortune are reduced.
Prima pars dividitur in duas: in prima ostendit quid sit fortuna; in secunda ex definitione fortunae assignat rationem eorum quae de fortuna dicuntur, ibi: infinitas quidem igitur causas et cetera. The first part is divided into two parts. First he shows what fortune is. Secondly, where he says, ‘It is necessary...’ (197 a 8; L9 #217), from the definition of fortune he explains the meaning [ ratio ] of those things which are said about fortune.
Circa primum tria facit: primo ponit quasdam divisiones ad investigandum definitionem fortunae; secundo ostendit sub quibus membris illarum divisionum fortuna contineatur, ibi: sicut igitur dictum est etc.; tertio concludit definitionem fortunae, ibi: manifestum est ergo et cetera. Concerning the first part he makes three points. First he sets forth certain divisions needed for the investigation of the definition of fortune. Secondly, where he says, ‘To resume then...’ (196 b 29 #215), he shows under which members of these divisions fortune is contained. Thirdly, where he says, ‘It is clear...’ (197 a 5 #216), he concludes to the definition of fortune.
Et quia fortuna ponitur ut causa quaedam, ad cognitionem autem causae oportet scire quorum sit causa, ponit primo divisionem ex parte eius cuius fortuna est causa; secundo ponit divisionem ex parte ipsius causae, ibi: huiusmodi igitur cum secundum accidens et cetera. Now since fortune is posited as a kind of cause, and since it is necessary, in order to understand a cause, to know that of which it is the cause, he first sets forth a division on the part of that of which fortune is the cause. Secondly, where he says, ‘Things of this kind...’ (196 b 23 #214), he sets forth a division on the part of the cause itself.
Circa primum ponit tres divisiones. 208. With reference to the first point he sets forth three divisions.
Quarum prima est, quod quaedam fiunt semper, ut ortus solis; quaedam sicut frequenter, ut quod homo nascatur oculatus: neutrum autem horum dicitur esse a fortuna. The first of these is that certain things always come to be, e.g., the rising of the sun; and certain things come to be frequently, e.g., man is born having eyes. But neither of these is said to be by fortune.
Sed quaedam fiunt praeter haec, idest ut in paucioribus, sicut quod homo nascatur cum sex digitis vel sine oculis: et omnes dicunt huiusmodi fieri a fortuna. Unde manifestum est quod fortuna aliquid est; cum esse a fortuna et esse ut in paucioribus convertantur. Et hoc inducit contra primam opinionem, quae negavit fortunam. But certain other things occur in fewer instances, as when a man is born with six fingers or without eyes. And everyone says that things of this sort come to be by fortune. Hence, it is clear that fortune is something, since to be by fortune and to be in fewer instances are convertible. And he brings this up in opposition to the first opinion which denied fortune.
Videtur autem divisio philosophi esse insufficiens, quia etiam quaedam contingentia sunt ad utrumlibet. Avicenna ergo dixit quod in his quae sunt ad utrumlibet, contingit aliquid esse a fortuna, sicut ea quae sunt in minori parte. Nec obstat quod non dicitur esse a fortuna quod Socrates sedeat, cum hoc sit ad utrumlibet: quia licet hoc sit ad utrumlibet respectu potentiae motivae, non tamen est ad utrumlibet respectu potentiae appetitivae, quae determinate tendit in unum; praeter quam si aliquid accideret, diceretur esse fortuitum. 209. However, it seems that this division of the Philosopher is insufficient, for there are some happenings which are indeterminate. Therefore Avicenna said that in those things which are indeterminate a thing happens to be by fortune, as for example those things which are occasional. And it is no objection that it is not said that it is by fortune that Socrates sits, since this is indeterminate. For although this is indeterminate with respect to the moving potency, it is not indeterminate with respect to the appetitive potency which tends determinately to one thing. And if something should happen outside of this, it would be said to be fortuitous.
Sed sicut potentia motiva, quae est ad utrumlibet, non exit in actum nisi per potentiam appetitivam determinetur ad unum; ita nihil quod est ad utrumlibet exit in actum nisi per aliquod determinetur ad unum: quia id quod est ad utrumlibet est sicut ens in potentia; potentia autem non est principium agendi, sed solum actus. Unde ex eo quod est ad utrumlibet nihil sequitur, nisi per aliquid aliud quod determinat ad unum, vel sicut semper vel sicut frequenter. Et propter hoc in iis quae fiunt, praetermisit ea quae sunt ad utrumlibet. Now just as the moving potency, which is indeterminate, does not move to act unless it is determined to one thing by the appetitive potency, so also nothing which is indeterminate moves to act unless it is determined to one thing by something. For that which is indeterminate is, as it were, being in potency. However, potency is not a principle of action, but only act is such. Hence from that which is indeterminate nothing follows unless it is determined to one thing by something, either always or frequently. And because of this, he omitted things which are indeterminate from his discussion of things which come to be.
Sciendum etiam quod quidam definierunt esse necessarium, quod non habet impedimentum; contingens vero sicut frequenter, quod potest impediri in paucioribus. 210. It must also be noted that some define the necessary as that which is never impeded and the contingent as that which occurs frequently but may be impeded in a few instances.
Sed hoc irrationabile est. Necessarium enim dicitur, quod in sui natura habet quod non possit non esse: contingens autem ut frequenter, quod possit non esse. Hoc autem quod est habere impedimentum vel non habere, est contingens. Natura enim non parat impedimentum ei quod non potest non esse; quia esset superfluum. But this is unreasonable. For that is called necessary which has in its nature that which cannot not be, whereas the contingent, as happening frequently, has in its nature that which can not be. But to have or not have some impediment is itself contingent. For nature does not prepare an impediment for that which cannot not be, since this would be superfluous.
Secundam divisionem ponit ibi: eorum autem quae fiunt etc.: et dicit quod quaedam fiunt propter finem, quaedam vero non. 211. He gives the second division where he says, ‘But secondly...’ (196 b 17). He says that some things come to be for the sake of an end, and other things do not.
Habet autem haec divisio dubitationem, quia omne agens agit propter finem, sive agat a natura, sive agat ab intellectu. This division, however, raises a difficulty, because every agent acts for an end; it acts either by nature or by intellect.
Sed sciendum est quod ea dicit non propter aliquid fieri, quae propter se fiunt, inquantum in seipsis habent delectationem vel honestatem, propter quam secundum seipsa placent. But we must note that he is saying that those things which come to be for themselves do not come to be for the sake of something, insofar as they have in themselves a pleasure or perfection because of which they are pleasing in themselves.
Vel dicit non propter finem fieri, quae non fiunt propter finem deliberatum; sicut confricatio barbae, vel aliquid huiusmodi, quod interdum fit absque deliberatione ex sola imaginatione movente: unde habent finem imaginatum, sed non deliberatum. Or else he is speaking of those things which do not occur for the sake of a deliberate end, for example, stroking the beard or some other such thing which takes place at times without deliberation solely from the movement of the imagination. Hence they have an imagined end, but not a deliberated end.
Tertiam divisionem ponit ibi: horum autem alia et cetera. Et dicit quod eorum quae fiunt propter finem, quaedam fiunt secundum voluntatem, et quaedam non: et ambo ista inveniuntur in iis quae fiunt propter aliquid. Non solum enim quae fiunt a voluntate, sed etiam ea quae fiunt a natura, propter aliquid fiunt. 212. He gives the third division where he says, ‘Again, some of the former...’ (196 b 18). He says that of the things which come to be for the sake of an end, some happen in accordance with will and others do not. Both of these are found among those things which come to be for the sake of something. For not only those things which come to be by will, but also those things which come to be by nature, come to be for the sake of something.
Et quia ea quae fiunt ex necessitate vel sicut frequenter, fiunt a natura vel a proposito, manifestum est quod tam in iis quae fiunt semper quam in iis quae fiunt frequenter, sunt aliqua quae fiunt propter finem: cum tam natura quam propositum propter finem operentur. 213. Now since those things which come to be either necessarily or frequently come to be from nature or from that which is proposed [by the intellect], it is clear that both in those things which always happen and in those things which happen frequently there are some things which come to be for an end. For both nature and that which is proposed [by the intellect] act for the sake of an end.
Et sic patet quod istae tres divisiones includunt se invicem; quia ea quae fiunt a proposito vel a natura, fiunt propter finem; et ea quae fiunt propter finem, fiunt semper aut frequenter. And thus it is clear that these three divisions include each other. For those things which come to be from what is proposed [by the intellect] or from nature come to be for the sake of an end, and those things which come to be for the sake of an end come to be always or frequently.
Deinde cum dicit: huiusmodi igitur cum secundum accidens etc., ponit divisionem quae sumitur ex parte causae. 214. Next where he says, ‘Things of this kind...’ (196 b 23), he gives the division which is taken on the part of the cause.
Et dicit quod cum huiusmodi, quae scilicet a proposito sunt, propter aliquid, et in minori parte, fiunt a causa secundum accidens, tunc dicimus ea esse a fortuna. Sicut enim entium quoddam est per se et quoddam per accidens, ita et causarum; sicut per se causa domus est ars aedificatoria, per accidens vero album vel musicum. He says that when things of this sort (i.e., things which are from what is proposed [by the intellect] for the sake of something, and which are in few instances) come to be through a per accidens cause, we say that they are by fortune. For as certain aspects of beings are per se and others per accidens, the same is true of causes. Thus the per se cause of a house is the builder’s art, while the per accidens cause is the white or the musical.
Sed considerandum est quod causa per accidens dicitur dupliciter: uno modo ex parte causae; alio modo ex parte effectus. But it must be noted that per accidens cause is taken in two ways: in one way on the part of the cause, and in another way on the part of the effect.
Ex parte quidem causae, quando illud quod dicitur causa per accidens, coniungitur causae per se; sicut si album vel musicum dicatur causa domus, quia accidentaliter coniungitur aedificatori. On the part of the cause, that which is called a per accidens cause is joined to the per se cause. Thus if the white and the musical are called causes of a house, it is because they are accidentally joined to the builder.
Ex parte autem effectus, quando accipitur aliquid quod accidentaliter coniungitur effectui; ut si dicamus quod aedificator est causa discordiae, quia ex domo facta accidit discordia. On the part of the effect, we sometimes refer to something which is accidentally joined to the effect, as when we say that a builder is the cause of strife because strife arises from the building of a house.
Et hoc modo dicitur fortuna esse causa per accidens, ex eo quod effectui aliquid coniungitur per accidens; utpote si fossurae sepulcri adiungatur per accidens inventio thesauri. Sicut enim effectus per se causae naturalis est quod consequitur secundum exigentiam suae formae, ita effectus causae agentis a proposito est illud quod accidit ex intentione agentis: unde quidquid provenit in effectu praeter intentionem, est per accidens. In this sense fortune is said to be a per accidens cause when something is accidentally, joined to the effect, for example, if the discovery of a treasure is accidentally joined to the digging of a grave. Thus the per se effect of a natural cause is what follows according to the exigencies of its form, so that the effect of the agent who acts through something proposed [by the intellect] is that which happens because of the intention of the agent. Hence whatever takes place in the effect outside this intention is per accidens.
Et hoc dico si id quod est praeter intentionem ut in paucioribus consequatur: quod enim vel semper vel ut frequenter coniungitur effectui, cadit sub eadem intentione. Stultum est enim dicere quod aliquis intendat aliquid, et non velit illud quod ut frequenter vel semper adiungitur. And I say that this is true if what is outside the intention follows in few cases. For what is always or frequently joined to the effect falls under the intention itself. For it is stupid to say that someone intends something but does not will that which is always or frequently joined to it.
Ponit autem differentiam inter causam per se et causam per accidens: quia causa per se est finita et determinata; causa autem per accidens est infinita et indeterminata, eo quod infinita uni possunt accidere. Moreover, he points out a difference between the per se cause the per accidens cause. The per se cause is limited and determinate, whereas the per accidens cause is unlimited and indeterminate, because an infinity of things can happen to be united.
Deinde cum dicit: sicut igitur dictum est etc., ostendit sub quibus membris praedictarum divisionum fortuna contineatur, et quod est a fortuna. 215. Next where he says, ‘To resume then...’(196 b 29), he points out those members of the above divisions under which fortune is contained, and what fortune is.
Et dicit primo quod fortuna et casus, ut prius dictum est, sunt in iis quae fiunt propter aliquid. Differentia autem casus et fortunae posterius determinabitur. He says first that fortune and chance, as was said above [#214], pertain to those things which happen for the sake of something. However, the difference between fortune and chance will be determined later [L10 #226ff].
Sed nunc hoc debet fieri manifestum, quod utrumque continetur in iis quae aguntur propter finem: sicut si aliquis sciret se recepturum pecuniam in foro, ivisset ad deportandum eam; sed si non propter hoc venit, per accidens est quod adventus eius fiat reportationis gratia, idest habeat hunc effectum. Et sic patet quod fortuna est causa per accidens eorum quae sunt propter aliquid. But now it should be clear that each of them is contained among those things which act for the sake of an end. Thus if one knows that he will receive money in the forum, and if he goes there to take it away, [this does not happen by fortune], but if he did not go there for this purpose, it is per accidens that his arrival should have this effect. And thus it is clear that fortune is a per accidens cause of things which are for the sake of something.
Item manifestum est quod est causa eorum quae sunt in minori parte; quia ista reportatio pecuniae dicitur fieri a fortuna, quando reportat ad villam veniens neque ex necessitate neque frequenter. Further it is clear that fortune is a cause of things which occur in few instances. For carrying money away is said to be by fortune when he who takes money away comes to the house neither necessarily nor frequently.
Item est in iis quae fiunt a proposito: quia reportatio pecuniae quae dicitur fieri a fortuna, est finis aliquarum causarum, non secundum seipsum, sicut in iis quae fiunt a natura, sed est finis eorum quae fiunt secundum propositum et ab intellectu. Sed si aliquis hoc proposito iret ut pecuniam reportaret, vel semper aut frequenter reportaret quando venit, non diceretur esse a fortuna: sicut si aliquis frequenter aut semper madefacit sibi pedes, quando vadit ad locum lutosum, et hoc licet non intendat, tamen hoc non dicitur esse a fortuna. Moreover, fortune pertains to those things which come to be because of what is proposed [by the intellect]. For taking money away, which is said to be by fortune, is the end of some causes, but not in itself, as in those things which happen by nature. Rather it is the end of those things which come to be as proposed by the intellect. But if someone acting under such a proposal should go in order to take money away, or if he always or frequently takes money away when he comes, this would not be said to be by fortune, just as if anyone frequently or always soaks his feet when he goes to a muddy place, it would not be said that this is due to fortune, even though he did not intend it.
Deinde cum dicit: manifestum est ergo etc., concludit ex praemissis definitionem fortunae. 216. Next where he says, ‘It is clear...’ (197 a 5), he concludes to a definition of fortune which is drawn from what was said above.
Et dicit manifestum esse ex praemissis quod fortuna est causa per accidens in his quae fiunt secundum propositum propter finem in minori parte. Et ex hoc patet quod fortuna et intellectus sunt circa idem: quia his tantum convenit agere a fortuna, quae habent intellectum; propositum enim vel voluntas non est sine intellectu. Et licet ea tantum agant a fortuna, quae habent intellectum, tamen quanto aliquid magis subiacet intellectui, tanto minus subiacet fortunae. He says that it is clear from the foregoing that fortune is a per accidens cause in those things which come to be in a few instances according to what is proposed for the sake of an end. And from this it is clear that fortune and intellect pertain to the same thing. For only those who have an intellect act by fortune, for there is no proposal or will without intellect. And although only those who have an intellect act by fortune, still the more something is subject to the intellect, the less is it subject to fortune.

Lectio 9 (197 a 8-35)
THE MEANING OF THE THINGS WHICH THE ANCIENT PHILOSOPHERS AND THE COMMON MAN SAY ABOUT FORTUNE
Chapter 5 cont.
ἀόριστα μὲν οὖν τὰ αἴτια ἀνάγκη εἶναι ἀφ' ὧν ἂν γένοιτο τὸ ἀπὸ τύχης. ὅθεν καὶ ἡ τύχη τοῦ ἀορίστου εἶναι δοκεῖ καὶ ἄδηλος ἀνθρώπῳ, It is necessary, no doubt, that the causes of what comes to pass by chance be indefinite; and that is why chance is supposed to belong to the class of the indefinite and to be inscrutable to man,
καὶ ἔστιν ὡς οὐδὲν ἀπὸ τύχης δόξειεν ἂν γίγνεσθαι. πάντα γὰρ ταῦτα ὀρθῶς λέγεται, εὐλόγως. ἔστιν μὲν γὰρ ὡς γίγνεται ἀπὸ τύχης· κατὰ συμβεβηκὸς γὰρ γίγνεται, καὶ ἔστιν αἴτιον ὡς συμβεβηκὸς ἡ τύχη· ὡς δ' ἁπλῶς οὐδενός· οἷον οἰκίας οἰκοδόμος μὲν αἴτιος, κατὰ συμβεβηκὸς δὲ αὐλητής, καὶ τοῦ ἐλθόντα κομίσασθαι τὸ ἀργύριον, μὴ τούτου ἕνεκα ἐλθόντα, ἄπειρα τὸ πλῆθος· καὶ γὰρ ἰδεῖν τινὰ βουλόμενος καὶ διώκων καὶ φεύγων καὶ θεασόμενος. and why it might be thought that, in a way, nothing occurs by chance. For all these statements are correct, because they are well grounded. Things do, in a way, occur by chance, for they occur incidentally and chance is an incidental cause. But strictly it is not the cause—without qualification—of anything; for instance, a housebuilder is the cause of a house; incidentally, a fluteplayer may be so. And the causes of the man's coming and getting the money (when he did not come for the sake of that) are innumerable. He may have wished to see somebody or been following somebody or avoiding somebody, or may have gone to see a spectacle.
καὶ τὸ φάναι εἶναί τι παράλογον τὴν τύχην ὀρθῶς· ὁ γὰρ λόγος ἢ τῶν ἀεὶ ὄντων ἢ τῶν ὡς ἐπὶ τὸ πολύ, ἡ δὲ τύχη ἐν τοῖς γιγνομένοις παρὰ ταῦτα. ὥστ' ἐπεὶ ἀόριστα τὰ οὕτως αἴτια, καὶ ἡ τύχη ἀόριστον. Thus to say that chance is a thing contrary to rule is correct. For 'rule' applies to what is always true or true for the most part, whereas chance belongs to a third type of event. Hence, to conclude, since causes of this kind are indefinite, chance too is indefinite.
ὅμως δ' ἐπ' ἐνίων ἀπορήσειεν ἄν τις, ἆρ' οὖν τὰ τυχόντα αἴτι' ἂν γένοιτο τῆς τύχης· οἷον ὑγιείας ἢ πνεῦμα ἢ εἵλησις, ἀλλ' οὐ τὸ ἀποκεκάρθαι· ἔστιν γὰρ ἄλλα ἄλλων ἐγγύτερα τῶν κατὰ συμβεβηκὸς αἰτίων. (Yet in some cases one might raise the question whether any incidental fact might be the cause of the chance occurrence, e.g. of health the fresh air or the sun's heat may be the cause, but having had one's hair cut cannot; for some incidental causes are more relevant to the effect than others.)
τύχη δὲ ἀγαθὴ μὲν λέγεται ὅταν ἀγαθόν τι ἀποβῇ, φαύλη δὲ ὅταν φαῦλόν τι, Chance or fortune is called 'good' when the result is good, 'evil' when it is evil.
εὐτυχία δὲ καὶ δυστυχία ὅταν μέγεθος ἔχοντα ταῦτα· διὸ καὶ τὸ παρὰ μικρὸν κακὸν ἢ ἀγαθὸν λαβεῖν μέγα ἢ εὐτυχεῖν ἢ ἀτυχεῖν ἐστίν, ὅτι ὡς ὑπάρχον λέγει ἡ διάνοια· τὸ γὰρ παρὰ μικρὸν ὥσπερ οὐδὲν ἀπέχειν δοκεῖ. The terms 'good fortune' and 'ill fortune' are used when either result is of considerable magnitude. Thus one who comes within an ace of some great evil or great good is said to be fortunate or unfortunate. The mind affirms the essence of the attribute, ignoring the hair's breadth of difference.
ἔτι ἀβέβαιον ἡ εὐτυχία εὐλόγως· ἡ γὰρ τύχη ἀβέβαιος· οὔτε γὰρ ἀεὶ οὔθ' ὡς ἐπὶ τὸ πολὺ οἷόν τ' εἶναι τῶν ἀπὸ τύχης οὐθέν. Further, it is with reason that good fortune is regarded as unstable; for chance is unstable, as none of the things which result from it can be invariable or normal.
ἔστι μὲν οὖν ἄμφω αἴτια, καθάπερ εἴρηται, κατὰ συμβεβηκός—καὶ ἡ τύχη καὶ τὸ αὐτόματον—ἐν τοῖς ἐνδεχομένοις γίγνεσθαι μὴ ἁπλῶς μηδ' ὡς ἐπὶ τὸ πολύ, καὶ τούτων ὅσ' ἂν γένοιτο ἕνεκά του. Both are then, as I have said, incidental causes—both chance and spontaneity—in the sphere of things which are capable of coming to pass not necessarily, nor normally, and with reference to such of these as might come to pass for the sake of something.
Posita definitione fortunae, hic ex praemissa definitione assignat rationem eorum quae de fortuna dicuntur. 217. Having given the definition of fortune, he establishes from this definition the meaning [ ratio ] of those things which are said about fortune.
Et primo eorum quae dicta sunt a philosophis antiquis de fortuna; secundo eorum quae ab hominibus vulgariter de fortuna dicuntur, ibi: et fortunam dicere et cetera. Posuit autem supra tres opiniones de fortuna et casu, quarum mediam improbavit tanquam omnino falsam; quia scilicet ponebat fortunam esse causam caeli et mundanorum omnium. First he considers those things which the ancient philosophers said about fortune. Secondly, where he says, ‘Thus to say...’ (197 a 18 #219), he considers those things which the common man says about fortune. He has given above [L7 #199ff] three opinions concerning fortune and chance. And he disproved the second of these opinions as being altogether false, for this position held that fortune is the cause of the heavens and of all worldly things.
Unde ea subtracta de medio, primo assignat quomodo veritatem habet tertia opinio, quae ponebat fortunam esse immanifestam homini; secundo quomodo veritatem habeat prima opinio, quae posuit nihil fieri a fortuna et a casu, ibi: et est ut a fortuna et cetera. Thus, having rejected the second opinion, he here shows that the third opinion, which holds that fortune is hidden to man, is true. Secondly, where he says, ‘... and why...’ (197 a 10 #218), he shows how the first opinion, which holds that nothing comes to be by fortune or chance, might be true.
Quia autem superius dictum est quod causae per accidens sunt infinitae; et iterum dictum est quod fortuna est causa per accidens; concludit ex praemissis quod eius quod est a fortuna, sunt infinitae causae. Et quia infinitum, secundum quod est infinitum, est ignotum, inde est quod fortuna immanifesta est homini. Since it was said above [L8 #214] that per accidens causes are infinite, and since it was also said [L8 #214] that fortune is a per accidens cause, he concludes from this that the causes of that which is by fortune are infinite. And since the infinite, insofar as it is infinite, is unknown, it follows that fortune is hidden to man.
Deinde cum dicit: et est ut a fortuna etc., ostendit quomodo prima opinio veritatem habeat: et dicit quod quodammodo est verum dicere quod a fortuna nihil fit. Haec enim omnia quae ab aliis dicta sunt de fortuna, quodammodo recte dicuntur, quia rationem aliquam habent. Cum enim fortuna sit causa per accidens, sequitur quod a fortuna sit aliquid per accidens; quod autem est per accidens, non est simpliciter; unde sequitur quod fortuna simpliciter nullius sit causa. 218. Next where he says,’... and why...’(197 a 10), he shows how the first opinion might be true. He says that in a way it is true to say that nothing comes to be by fortune. For all of those things which others say about fortune are in a certain respect true, because they have some meaning [ ratio ]. Since fortune is a per accidens cause, it follows that what is by fortune is something per accidens. But what is per accidens is not simply. Hence it follows that fortune is not the cause of anything simply.
Et hoc quod dixerat circa utramque opinionem, manifestat per exempla: et dicit quod sicut aedificator est causa per se domus et simpliciter, tibicen autem est causa domus per accidens; similiter quod aliquis veniat ad aliquem locum non causa deportandi argentum, est causa reportationis per accidens. Sed haec causa per accidens infinita est: quia infinitis aliis de causis potest homo ire ad locum illum; puta si vadat causa visitandi aliquem, vel causa persequendi hostem, vel causa fugiendi persequentem, vel causa videndi aliqua spectabilia. Omnia autem ista et quaecumque similia sunt causa reportationis argenti quae contingit a fortuna. And he clarifies what he has said about each of these opinions through an example. He says that as the builder is the per se cause of a house and is the cause simply, whereas flute player is a per accidens cause of the house; in like manner the fact that someone should come to a place with no intention of taking money away is a per accidens cause of carrying it away. But this per accidens cause is infinite, because it is possible for a man to go to that place because of an infinity of other reasons, e.g., if he came to visit someone, or to pursue an enemy, or to escape from a pursuer, or to see a show of some sort. Now all these things and anything similar are causes of the taking of money which happens by chance.
Deinde cum dicit: et fortunam dicere etc., assignat rationem eorum quae dicuntur de fortuna vulgariter. 219. Next where he says, ‘Thus to say...’ (197 a 18), he explains the meaning [ ratio ] of those things which are commonly said about fortune.
Et primo assignat rationem eius quod dicitur de fortuna, esse sine ratione; secundo eius quod dicitur, fortunam esse bonam vel malam, ibi: fortuna autem dicitur et cetera. First he explains why it is said that that which is by fortune is without reason [ ratio ]. Secondly, where he says, ‘Chance, or fortune...’ (197 a 25 #222), he explains why it is said that fortune is good or bad.
Circa primum duo facit: primo ostendit propositum; secundo movet quandam dubitationem, ibi: tamen deficiet in quibusdam et cetera. Concerning the first part he makes two points. First he proves his position. Secondly he raises a certain difficulty where he says, ‘Yet in some cases...’ (197 a 21 #221).
Dicit ergo primo quod recte dicitur fortunam esse sine ratione: quia ratiocinari non possumus nisi de iis quae sunt semper vel frequenter; fortuna autem est extra utrumque. Et ideo, quia causae tales, in paucioribus existentes, sunt per accidens et infinitae et sine ratione, sequitur quod fortunae sint causae infinitae et sine ratione: omnis enim causa per se producit effectum suum vel semper, vel ut frequenter. 220. He says, therefore, first that fortune is rightly said to be without reason [ ratio ]. For we can reason only about those things which happen always or in most instances. But fortune lies outside of both of these. And so since such causes, which occur in exceptional cases, are per accidens and infinite and without reason [ ratio ], it follows that causes by fortune are infinite and without reason [ ratio ]. For every per se cause produces its effect either always or in most cases.
Deinde cum dicit: tamen deficiet etc.; movet quandam dubitationem: et dicit quod licet dicatur quod fortuna est causa per accidens, in quibusdam tamen deficiet, idest dubitabit aliquis. 221. Next where he says, ‘Yet in some cases...’ (197 a 21), he raises a certain difficulty. He says that although it may be said that fortune is a per accidens cause, some will question this.
Et est dubitatio utrum quaecumque contingit esse causas per accidens, debeant dici causa eius quod fit a fortuna. Sicut patet quod sanitatis causa per se potest esse vel natura vel ars medicinae; causae autem per accidens possunt dici omnia illa, quibus contingentibus contingit fieri sanitatem, sicut est spiritus, idest ventus, et aestus et abrasio capitis: numquid igitur quodlibet istorum est causa per accidens? The problem is whether everything which happens to be a per accidens cause ought to be called a cause of that which comes to be by fortune. Thus it is clear that the per se cause of health can be either nature or the art of the doctor. However, can all those things with which the coming to be of health happens to be connected, such as the wind, and the heat, and shaving of the head, be called causes per accidens ? The question, therefore, is whether each of these is a cause per accidens.
Sed quia supra diximus quod fortuna maxime dicitur causa per accidens ex parte effectus, prout scilicet aliquid dicitur esse causa eius quod accidit effectui; manifestum est quod causa fortuita aliquid operatur ad effectum fortuitum, licet non intendat illud, sed aliquid aliud effectui coniunctum. Et secundum hoc ventus aut aestus possunt dici causae fortuitae sanitatis, inquantum faciunt aliquam alterationem in corpore, ad quam sequitur sanitas: sed depilatio, aut aliquid aliud huiusmodi non facit manifeste aliquid ad sanitatem. Now since we said above [L8 #214] that fortune is most properly called a per accidens cause on the part of the effect, since a thing is said to be a cause of that which happens to the effect, it is clear that a fortuitous cause produces something in the fortuitous effect although it does not intend that, but rather something else connected with the effect. According to this wind or heat can be called fortuitous causes of health insofar as they produce some change in the body, upon which change health follows. But removing the hair or some other such thing does not produce anything clearly related to health.
Sed tamen inter causas per accidens aliquae sunt propinquiores, et aliquae remotiores. Illae autem quae sunt remotiores, minus videntur esse causae. But among the per accidens causes, some are nearer [to the per se cause] and others are more remote. Those which are more remote seem less to be causes.
Deinde cum dicit: fortuna autem etc., assignat rationem eius quod dicitur, fortunam esse bonam vel malam. 222. Next where he says, ‘Chance or fortune...’ (197 a 25), he explains why fortune is said to be good or bad.
Et primo assignat rationem quare dicitur fortuna bona vel mala simpliciter. Et dicit quod fortuna dicitur bona quando aliquod bonum contingit; et mala quando malum. First he explains why fortune is said to be good or bad simply. He says that fortune is said to be good when something good happens and bad when something bad happens.
Secundo ibi: eufortunium etc., assignat rationem eufortunii et infortunii. 223. Secondly, where he says, ‘The terms “good fortune”...’ (197 a 26), he explains the meaning [ ratio ] of good fortune and misfortune.
Et dicit quod eufortunium et infortunium dicitur, quando habet aliquod bonum vel malum cum magnitudine: nam eufortunium dicitur quando sequitur aliquod magnum bonum; infortunium autem quando sequitur aliquod magnum malum. He says that we refer to good fortune and misfortune when [the fortuitous event] has some great good or great evil. For an event is called good fortune when some great good follows; it is called misfortune when some great evil follows.
Et quia privari bono accipitur in ratione mali, et privari malo in ratione boni; ideo quando aliquis parum distat a magno bono, si amittat illud, dicitur infortunatus; et si aliquis sit propinquus magno malo, et liberetur ab illo, dicitur eufortunatus; et hoc ideo, quia intellectus accipit illud quod parum distat, ac si nihil distaret, sed iam haberetur. And since being deprived of a good is included in the notion [ ratio ] of evil, and being deprived of evil is included in the notion [ ratio ] of the good, then when one is a little removed from a great good, he is said to be unfortunate if he misses it. On the other hand, if one is close to a great evil and is freed from it, he is said to be fortunate. This is so because the intellect takes that which is only a little removed as if it were not removed at all, but already possessed.
Tertio ibi: amplius incertum etc., assignat rationem quare eufortunia sint incerta: et dicit quod hoc ideo est, quia eufortunium fortuna quaedam est; fortuna autem est incerta, cum sit eorum quae non sunt semper neque frequenter, ut dictum est. Unde sequitur eufortunium esse incertum. 224. Thirdly where he says, ‘Further, it is with reason...’ (197 a 30), he explains why good fortune is uncertain. He says that this is so because good fortune is a kind of fortune. But fortune is uncertain because it pertains to things which are neither always nor frequent, as was said.’ Hence it follows that good fortune is uncertain.
Ultimo ibi: sunt quidem igitur ambo etc., concludit quasi recapitulando quod utrumque, scilicet casus et fortuna, est causa per accidens; et utrumque est in iis quae contingunt non simpliciter, idest semper, neque frequenter; et utrumque est in iis quae fiunt propter aliquid, ut ex supra dictis patet. 225. Finally where he says, ‘Both are then...’ (197 a 33), he concludes as a sort of résumé that each, i.e., chance and fortune, is a cause per accidens, and that each pertains to things which do not happen simply, i.e., neither always nor frequently, and that each pertains to things which come to be for the sake of something, as is clear from what was said above [L7 #198ff].

Lectio 10 (197 a 36-198 a 21)
THE DIFFERENCE BETWEEN CHANCE AND FORTUNE.
THE CAUSES ARE NEITHER MORE NOR LESS THAN FOUR
Chapter 6
Διαφέρει δ' ὅτι τὸ αὐτόματον ἐπὶ πλεῖόν ἐστι· τὸ μὲν γὰρ ἀπὸ τύχης πᾶν ἀπὸ ταὐτομάτου, τοῦτο δ' οὐ πᾶν (197b.) ἀπὸ τύχης. They differ in that 'spontaneity' is the wider term. Every result of chance is from what is spontaneous, but not everything that is from what is spontaneous is from chance.
ἡ μὲν γὰρ τύχη καὶ τὸ ἀπὸ τύχης ἐστὶν ὅσοις καὶ τὸ εὐτυχῆσαι ἂν ὑπάρξειεν καὶ ὅλως πρᾶξις. διὸ καὶ ἀνάγκη περὶ τὰ πρακτὰ εἶναι τὴν τύχην (σημεῖον δ' ὅτι δοκεῖ ἤτοι ταὐτὸν εἶναι τῇ εὐδαιμονίᾳ ἡ εὐτυχία ἢ ἐγγύς, ἡ δ' εὐδαιμονία πρᾶξίς τις· εὐπραξία γάρ), ὥσθ' ὁπόσοις μὴ ἐνδέχεται πρᾶξαι, οὐδὲ τὸ ἀπὸ τύχης τι ποιῆσαι. Chance and what results from chance are appropriate to agents that are capable of good fortune and of moral action generally. Therefore necessarily chance is in the sphere of moral actions. This is indicated by the fact that good fortune is thought to be the same, or nearly the same, as happiness, and happiness to be a kind of moral action, since it is well-doing. Hence what is not capable of moral action cannot do anything by chance.
καὶ διὰ τοῦτο οὔτε ἄψυχον οὐδὲν οὔτε θηρίον οὔτε παιδίον οὐδὲν ποιεῖ ἀπὸ τύχης, ὅτι οὐκ ἔχει προαίρεσιν· οὐδ' εὐτυχία οὐδ' ἀτυχία ὑπάρχει τούτοις, εἰ μὴ καθ' ὁμοιότητα, ὥσπερ ἔφη Πρώταρχος εὐτυχεῖς εἶναι τοὺς λίθους ἐξ ὧν οἱ βωμοί, ὅτι τιμῶνται, οἱ δὲ ὁμόζυγες αὐτῶν καταπατοῦνται. τὸ δὲ πάσχειν ἀπὸ τύχης ὑπάρξει πως καὶ τούτοις, ὅταν ὁ πράττων τι περὶ αὐτὰ πράξῃ ἀπὸ τύχης, ἄλλως δὲ οὐκ ἔστιν· Thus an inanimate thing or a lower animal or a child cannot do anything by chance, because it is incapable of deliberate intention; nor can 'good fortune' or 'ill fortune' be ascribed to them, except metaphorically, as Protarchus, for example, said that the stones of which altars are made are fortunate because they are held in honour, while their fellows are trodden under foot. Even these things, however, can in a way be affected by chance, when one who is dealing with them does something to them by chance, but not otherwise.
τὸ δ' αὐτόματον καὶ τοῖς ἄλλοις ζῴοις καὶ πολλοῖς τῶν ἀψύχων, οἷον ὁ ἵππος αὐτόματος, φαμέν, ἦλθεν, ὅτι ἐσώθη μὲν ἐλθών, οὐ τοῦ σωθῆναι δὲ ἕνεκα ἦλθε· καὶ ὁ τρίπους αὐτόματος κατέπεσεν· ἔστη μὲν γὰρ τοῦ καθῆσθαι ἕνεκα, ἀλλ' οὐ τοῦ καθῆσθαι ἕνεκα κατέπεσεν. The spontaneous on the other hand is found both in the lower animals and in many inanimate objects. We say, for example, that the horse came 'spontaneously', because, though his coming saved him, he did not come for the sake of safety. Again, the tripod fell 'of itself', because, though when it fell it stood on its feet so as to serve for a seat, it did not fall for the sake of that.
ὥστε φανερὸν ὅτι ἐν τοῖς ἁπλῶς ἕνεκά του γιγνομένοις, ὅταν μὴ τοῦ συμβάντος ἕνεκα γένηται ὧν ἔξω τὸ αἴτιον, τότε ἀπὸ τοῦ αὐτομάτου λέγομεν· ἀπὸ τύχης δέ, τούτων ὅσα ἀπὸ τοῦ αὐτομάτου γίγνεται τῶν προαιρετῶν τοῖς ἔχουσι προαίρεσιν. Hence it is clear that events which (1) belong to the general class of things that may come to pass for the sake of something, (2) do not come to pass for the sake of what actually results, and (3) have an external cause, may be described by the phrase 'from spontaneity'. These 'spontaneous' events are said to be 'from chance' if they have the further characteristics of being the objects of deliberate intention and due to agents capable of that mode of action.
σημεῖον δὲ τὸ μάτην, ὅτι λέγεται ὅταν μὴ γένηται τὸ ἕνεκα ἄλλου ἐκείνου ἕνεκα, οἷον εἰ τὸ βαδίσαι λαπάξεως ἕνεκά ἐστιν, εἰ δὲ μὴ ἐγένετο βαδίσαντι, μάτην φαμὲν βαδίσαι καὶ ἡ βάδισις ματαία, ὡς τοῦτο ὂν τὸ μάτην, τὸ πεφυκὸς ἄλλου ἕνεκα, ὅταν μὴ περαίνῃ ἐκεῖνο οὗ ἕνεκα ἦν καὶ ἐπεφύκει, ἐπεὶ εἴ τις λούσασθαι φαίη μάτην ὅτι οὐκ ἐξέλιπεν ὁ ἥλιος, γελοῖος ἂν εἴη· οὐ γὰρ ἦν τοῦτο ἐκείνου ἕνεκα. οὕτω δὴ τὸ αὐτόματον καὶ κατὰ τὸ ὄνομα ὅταν αὐτὸ μάτην γένηται· κατέπεσεν γὰρ οὐ τοῦ πατάξαι ἕνεκεν ὁ λίθος· ἀπὸ τοῦ αὐτομάτου ἄρα κατέπεσεν ὁ λίθος, ὅτι πέσοι ἂν ὑπὸ τινὸς καὶ τοῦ πατάξαι ἕνεκα. This is indicated by the phrase 'in vain', which is used when A which is for the sake of B, does not result in B. For instance, taking a walk is for the sake of evacuation of the bowels; if this does not follow after walking, we say that we have walked 'in vain' and that the walking was 'vain'. This implies that what is naturally the means to an end is 'in vain', when it does not effect the end towards which it was the natural means—for it would be absurd for a man to say that he had bathed in vain because the sun was not eclipsed, since the one was not done with a view to the other. Thus the spontaneous is even according to its derivation the case in which the thing itself happens in vain. The stone that struck the man did not fall for the purpose of striking him; therefore it fell spontaneously, because it might have fallen by the action of an agent and for the purpose of striking.
μάλιστα δ' ἐστὶ χωριζόμενον τοῦ ἀπὸ τύχης ἐν τοῖς φύσει γιγνομένοις· ὅταν γὰρ γένηταί τι παρὰ φύσιν, τότε οὐκ ἀπὸ τύχης ἀλλὰ μᾶλλον ἀπὸ ταὐτομάτου γεγονέναι φαμέν. ἔστι δὲ καὶ τοῦτο ἕτερον· τοῦ μὲν γὰρ ἔξω τὸ αἴτιον, τοῦ δ' ἐντός. (198a.) τί μὲν οὖν ἐστιν τὸ αὐτόματον καὶ τί ἡ τύχη, εἴρηται, καὶ τί διαφέρουσιν ἀλλήλων. The difference between spontaneity and what results by chance is greatest in things that come to be by nature; for when anything comes to be contrary to nature, we do not say that it came to be by chance, but by spontaneity. Yet strictly this too is different from the spontaneous proper; for the cause of the latter is external, that of the former internal. We have now explained what chance is and what spontaneity is, and in what they differ from each other.
τῶν δὲ τρόπων τῆς αἰτίας ἐν τοῖς ὅθεν ἡ ἀρχὴ τῆς κινήσεως ἑκάτερον αὐτῶν· ἢ γὰρ τῶν φύσει τι ἢ τῶν ἀπὸ διανοίας αἰτίων ἀεί ἐστιν· ἀλλὰ τούτων τὸ πλῆθος ἀόριστον. Both belong to the mode of causation 'source of change', for either some natural or some intelligent agent is always the cause; but in this sort of causation the number of possible causes is infinite.
ἐπεὶ δ' ἐστὶ τὸ αὐτόματον καὶ ἡ τύχη αἴτια ὧν ἂν ἢ νοῦς γένοιτο αἴτιος ἢ φύσις, ὅταν κατὰ συμβεβηκὸς αἴτιόν τι γένηται τούτων αὐτῶν, οὐδὲν δὲ κατὰ συμβεβηκός ἐστι πρότερον τῶν καθ' αὑτό, δῆλον ὅτι οὐδὲ τὸ κατὰ συμβεβηκὸς αἴτιον πρότερον τοῦ καθ' αὑτό. ὕστερον ἄρα τὸ αὐτόματον καὶ ἡ τύχη καὶ νοῦ καὶ φύσεως· ὥστ' εἰ ὅτι μάλιστα τοῦ οὐρανοῦ αἴτιον τὸ αὐτόματον, ἀνάγκη πρότερον νοῦν αἴτιον καὶ φύσιν εἶναι καὶ ἄλλων πολλῶν καὶ τοῦδε τοῦ παντός. Spontaneity and chance are causes of effects which though they might result from intelligence or nature, have in fact been caused by something incidentally. Now since nothing which is incidental is prior to what is per se, it is clear that no incidental cause can be prior to a cause per se. Spontaneity and chance, therefore, are posterior to intelligence and nature. Hence, however true it may be that the heavens are due to spontaneity, it will still be true that intelligence and nature will be prior causes of this All and of many things in it besides.
Chapter 7
Ὅτι δὲ ἔστιν αἴτια, καὶ ὅτι τοσαῦτα τὸν ἀριθμὸν ὅσα φαμέν, δῆλον· τοσαῦτα γὰρ τὸν ἀριθμὸν τὸ διὰ τί περιείληφεν· ἢ γὰρ εἰς τὸ τί ἐστιν ἀνάγεται τὸ διὰ τί ἔσχατον, ἐν τοῖς ἀκινήτοις (οἷον ἐν τοῖς μαθήμασιν· εἰς ὁρισμὸν γὰρ τοῦ εὐθέος ἢ συμμέτρου ἢ ἄλλου τινὸς ἀνάγεται ἔσχατον), ἢ εἰς τὸ κινῆσαν πρῶτον (οἷον διὰ τί ἐπολέμησαν; ὅτι ἐσύλησαν), ἢ τίνος ἕνεκα (ἵνα ἄρξωσιν), ἢ ἐν τοῖς γιγνομένοις ἡ ὕλη. ὅτι μὲν οὖν τὰ αἴτια ταῦτα καὶ τοσαῦτα, φανερόν· It is clear then that there are causes, and that the number of them is what we have stated. The number is the same as that of the things comprehended under the question 'why'. The 'why' is referred ultimately either (1), in things which do not involve motion, e.g. in mathematics, to the 'what' (to the definition of 'straight line' or 'commensurable', etc.), or (2) to what initiated a motion, e.g. 'why did they go to war?—because there had been a raid'; or (3) we are inquiring 'for the sake of what?'—'that they may rule'; or (4), in the case of things that come into being, we are looking for the matter. The causes, therefore, are these and so many in number.
Postquam philosophus determinavit de fortuna et casu quantum ad ea in quibus conveniunt, hic ostendit differentiam eorum ad invicem. 226. Having treated fortune and chance with reference to those aspects in which they are alike, the Philosopher here explains the difference between them.
Et dividitur in duas partes: in prima ostendit differentiam fortunae et casus; in secunda ostendit ubi maxime haec differentia consistit, ibi: maxime autem et cetera. This section is divided into two parts. First he explains the difference between fortune and chance. Secondly, where he says, ‘The difference between...’ (197 b 32 #235), he explains that in which this difference primarily consists.
Prima dividitur in duas: in prima ostendit differentiam inter casum et fortunam; in secunda recapitulat quae dicta sunt de utroque, ibi: quare manifestum est et cetera. The first part is divided into two parts. First he explains the difference between chance and fortune. Secondly, where he says, ‘Hence it is clear...’ (197 b 18 #235), he summarizes what he has said about each of them.
Circa primum duo facit: primo ponit differentiam inter casum et fortunam; et dicit quod in hoc differunt, quod casus est in plus quam fortuna, quia omne quod est a fortuna est a casu, sed non convertitur. 227. Concerning the first part he makes two points. First he explains the difference between chance and fortune. He says that they differ by reason of the fact that chance pertains to more things than fortune, because everything which is by fortune is by chance, but not conversely.
Secundo, ibi: fortuna quidem enim etc., manifestat praedictam differentiam. 228. Secondly, where he says, ‘Chance and what results...’ (197 b 1), he clarifies the difference mentioned above.
Et primo ostendit in quibus sit fortuna; secundo quod casus in pluribus est, ibi: sed casus in aliis et cetera. First he designates the things in which fortune is found. Secondly, where he says, ‘The spontaneous...’ (197 b 14 #231), he shows that chance is found in more things.
Circa primum duo facit: primo ostendit in quibus sit fortuna; secundo concludit in quibus non sit, ibi: et propter hoc neque inanimatum et cetera. Concerning the first part he makes two points. First he designates the things in which fortune is found. Secondly, where he says, ‘Thus an inanimate thing...’ (197 b 6 #230), he draws a conclusion about those things in which fortune is not found.
Dicit ergo primo quod fortuna et id quod est a fortuna, invenitur in illis quibus bene contingere aliquid dicitur; quia in quibus est fortuna, potest esse eufortunium et infortunium. 229. He says, therefore, first that fortune and that which is by fortune are found in those things in which something is said to happen well. For fortune is found in those things in which there can be good fortune and misfortune.
Dicitur autem bene contingere illi aliquid cuius est agere. Eius autem proprie est agere, quod habet dominium sui actus; quod autem non habet dominium sui actus, magis agitur quam agat; et ideo actus non est in potestate eius quod agitur, sed magis eius quod agit ipsum. Now a thing is said to happen well for him to whom action belongs. However, action belongs properly to him who has dominion over his action. For what does not have dominion over its action is that which is acted upon rather than that which acts. And thus action is not in the power of that which is acted upon, but rather in the power of that which acts.
Et quia vita practica, sive activa est eorum quae habent dominium sui actus (in his enim invenitur operari secundum virtutem vel vitium), ideo necesse est quod fortuna sit circa practica. Now since the active or practical life pertains to those who have dominion over their acts (for here is where operation according to virtue or vice is found), it is necessary that fortune pertains to the practical.
Et huius signum inducit, quia fortuna videtur vel idem esse felicitati vel ei esse propinqua: unde vulgariter felices bene fortunati vocantur. Secundum enim illos qui felicitatem in bonis exterioribus consistere putant, felicitas est idem fortunae: secundum illos vero qui bona exteriora, in quibus plurimum habet locum fortuna, dicunt deservire instrumentaliter ad felicitatem, secundum hoc bona fortuna est propinqua felicitati, quia coadiuvat ad ipsam. A sign of this is the fact that fortune seems to be the same as happiness, or very nearly so. Hence the happy are commonly called the fortunate. For according to those who think that happiness consists in external goods, happiness is the same as fortune; according to those, however, who say that external goods, in which fortune plays a great part, help as instruments in the attainment of happiness, good fortune is close to happiness because it helps one attain it.
Unde cum felicitas sit quaedam operatio (est enim eupraxia, idest bona operatio, scilicet virtutis perfectae, ut dicitur in I Ethic.), sequitur quod fortuna sit in illis quibus contingit bene agere vel impediri ab hoc. Et hoc est bene contingere vel male contingere. Unde cum aliquis sit dominus sui actus inquantum voluntarie agit, sequitur quod in illis tantum contingat aliquid a fortuna esse, quae voluntarie agit, non autem in aliis. Hence, since happiness is a certain operation (for it is good operation, i.e., that of perfected virtue, as is said in Ethics, I:7, it follows that fortune pertains to the actions in which one happens to act well or is impeded from acting well. And this means that things turn out either well or badly. Hence, since one has dominion over his actions insofar as he acts voluntarily, it follows that in those actions alone where one acts voluntarily should something happen by fortune, but not in others.
Deinde cum dicit: et propter hoc neque inanimatum etc., concludit ex praemissis in quibus non sit fortuna. 230. Next where he says, ‘Thus an inanimate thing...’(197 b 6), he draws from the above a conclusion about the things in which fortune is not found.
Et dicit quod propter hoc quod fortuna non est nisi in his quae voluntarie agunt, inde est quod neque inanimatum neque puer neque bestia, cum non agant voluntarie quasi liberum arbitrium habentes (quod hic dicit propositum), non agunt a fortuna. Unde nec eufortunium nec infortunium in his potest accidere nisi similitudinarie: sicut quidam dixit quod lapides ex quibus fiunt altaria, sunt fortunati, quia eis honor et reverentia exhibetur, cum lapides eis coniuncti conculcentur; quod dicitur per similitudinem ad homines, in quibus honorati videntur bene fortunati; hi autem qui conculcantur, dicuntur male fortunati. He says that since fortune is found only in those who act voluntarily, it follows that neither an inanimate thing, nor a child, nor a beast act by fortune, since they do not act voluntarily as having free choice (which is here called ‘that which is proposed’). Hence, neither good fortune nor misfortune can happen to them except metaphorically. Thus, someone said that the stones from which altars are built are fortunate because honour and reverence are shown them, but the stones next to the altar stones are walked upon. This is said because of a certain likeness to men among whom the honoured seemed to be fortunate, whereas those stones which are walked upon are called unfortunate.
Sed quamvis praemissis non contingat agere a fortuna, nihil tamen prohibet ea pati a fortuna, cum aliquod agens voluntarium circa ea operatur: sicut dicimus esse eufortunium cum aliquis homo invenit thesaurum, vel infortunium cum percutitur a lapide cadente. But although it follows from the foregoing that such things do not act by fortune, there is nothing to prevent them from being acted upon by fortune. For some voluntary agent may act upon them. Thus, we say that it is good fortune when a man finds a treasure, or it is a misfortune when he is struck by a falling stone.
Deinde cum dicit: sed casus et in aliis etc., ostendit quod casus est etiam in aliis. 231. Next where he says, ‘The spontaneous...’ (197 b 14), he points out that chance is found also in other things.
Et circa hoc tria facit: primo ostendit quod casus est in aliis; secundo concludit quandam conclusionem ex dictis, ibi: quare manifestum est etc.; tertio ad eius manifestationem quoddam signum inducit, ibi: signum autem est et cetera. Concerning this he makes three points. First, he shows that chance is found in other things. Secondly, where he says, ‘Hence it is clear...’ (197 b 18 #233), he draws a certain conclusion from what was said above. Thirdly, where he says, ‘This is indicated...’ (197 b 23 #234), he uses an example to clarify the point.
Dicit ergo primo: quod casus non solum est in hominibus, qui voluntarie agunt, sed etiam in aliis animalibus, et etiam in rebus inanimatis. Et ponit exemplum de aliis animalibus, sicut dicitur quod equus casu venit, quando salutem adeptus est veniens, licet non venerit causa salutis. Aliud exemplum ponit in rebus inanimatis: dicimus enim quod tripoda cecidit casu, quia sic stat per casum ut sit apta ad sedendum, licet non ista de causa ceciderit, ut staret apta ad sedendum. 232. He says, therefore, first that chance is found not only in men, who act voluntarily, but also in other animals and even in inanimate things. He gives an example dealing with other animals. It is said that a horse comes by chance when his coming is conducive to his safety, although he did not come for the sake of safety. He gives another example taken from inanimate things. We say that a tripod falls by chance because, as it stands, it is suitable for sitting, although it did not fall for the sake of this, i.e., so that someone might sit on it.
Deinde cum dicit: quare manifestum est etc., concludit ex praemissis quod in iis quae simpliciter fiunt propter aliquid, quando non fiunt causa eius quod accidit, sed fiunt causa alicuius extrinseci, tunc dicimus quod fiant a casu. Sed a fortuna dicimus illa fieri tantum de numero eorum quae fiunt a casu, quaecumque accidunt in habentibus propositum. 233. Next where he says, ‘Hence it is clear...’ (197 b 18), he draws the following conclusion from the above. When things which come to be simply for the sake of something do not come to be for the sake of that which happens, but for the sake of something extrinsic, then we say that these things come to be by chance. But we say that among the things which come to be by chance, only those things which happen in those who have free choice come to be by fortune.
Deinde cum dicit: signum autem est etc., manifestat quod in conclusione posuerat, scilicet quod casus accidat in his quae sunt propter aliquid. 234. Next where he says, ‘This is indicated...’(197 b 23), he clarifies what he has stated in this conclusion, i.e., that chance occurs in those things which happen for the sake of something.
Et accipit signum ab eo quod dicitur vanum, quod secundum nomen in Graeco propinquum est casui. Dicitur autem vanum, cum id quod est propter aliquid, non fiat eius causa, idest cum non accidat ex eo propter quod fit; sicut si aliquis ambulet ad deponendum superflua naturae, si hoc non accidat deambulanti, dicitur frustra deambulasse, et ambulatio eius esset vana. Ac si hoc sit frustra vel vanum, quod aptum natum est fieri causa alicuius, cum non perficiat illud cuius causa natum est fieri. A sign of this is the fact that the word ‘vain’ is used, which in the Greek is close to chance. For we use the term ‘vain’ when that which is for the sake of something does not come to be because of that something, i.e., when that for the sake of which something is done does not occur. Thus if one should walk in order to evacuate the bowels, and if this should not occur to the walker, then he is said to have walked in vain, and his walking would be vain. Thus that which is suitable for the coming to be of something is vain and frustrated when it does not accomplish that for whose coming to be it is suitable.
Et quare dicat cuius causa natum est fieri, exponit subdens quia si aliquis dicat se frustra balneatum quia eo balneato non deficit sol, derisorie diceret; quia hoc quod est ipsum esse balneatum, non erat natum fieri propter hoc quod deficeret sol. He explains why he says ‘that for whose coming to be it is suitable’. If someone were to say that he bathed in vain because the sun was not eclipsed while he bathed, he would speak ridiculously, because bathing oneself is not apt for producing an eclipse of the sun.
Unde casus, qui in Graeco dicitur automatum, idest per se frustra, accidit in his quae sunt propter aliquid, sicut et id quod est frustra vel vanum: quia per se frustra ipsum frustra secundum suum nomen significat, sicut per se homo ipsum hominem et per se bonum ipsum bonum. Hence chance, which in the Greek is called ‘automatum’, i.e., per se vain, occurs in those things which are for the sake of something. This is also true of that which is frustrated or vain. For the name per se vain signifies the very thing which is frustrated, just as per se man signifies man himself and per se good signifies good itself.
Et exemplificat in his quae casu fiunt, sicut cum dicitur quod lapis cadendo percutiens aliquem, cecidit non percutiendi causa. Ergo cecidit ab eo quod est per se vanum vel per se frustra, quia non natus est propter hoc cadere: cadit enim aliquando lapis ab aliquo emissus percutiendi causa. He gives an example of things which happen by chance. Thus fit is chance] when it is said that a stone, which strikes someone when falling, did not fall for the purpose of striking him. Therefore it fen because of that which is per se vain or per se frustrated, for the stone does not naturally fall for this purpose. However at times a stone does fall as thrown by someone for the purpose of hitting another.
Quamvis autem casus et vanum conveniant in hoc quod utrumque est in his quae sunt propter aliquid, differunt tamen, quia vanum dicitur ex hoc quod non consequitur illud quod intendebatur; casus autem dicitur ex hoc quod consequitur aliquid aliud quod non intendebatur. However, although chance and the vain are alike insofar as each is among the things which are for the sake of something, nevertheless they also differ. For a thing is called vain because of the fact that that which was intended does not follow, whereas a thing is called chance because of the fact that something else which was not intended does follow.
Unde quandoque est vanum et casus simul, puta cum non accidit illud quod intendebatur, sed accidit aliquid aliud: quandoque autem est casus sed non vanum, cum accidit et illud quod intendebatur et aliud: quandoque autem est vanum et non casus, quando non accidit illud quod intendebatur neque aliquid aliud. Hence sometimes a thing is vain and chance at the same time, for example, when that which was intended does not occur but something else does occur. However, sometimes there is chance but not the vain, as when both that which was intended and something else occur. And there is the vain and no chance when neither that which was intended nor anything else occurs.
Deinde cum dicit: maxime autem etc., ostendit in quibus maxime casus differat a fortuna. 235. Next where he says, ‘The difference...’ (197 b 32), he explains that in which chance most of all differs from fortune.
Et dicit quod maxime differt in illis quae fiunt a natura; quia ibi habet locum casus, sed non fortuna. Cum enim aliquid fit extra naturam in operationibus naturae, puta cum nascitur sextus digitus, tunc non dicimus quod fiat a fortuna, sed magis ab eo quod est per se frustra, idest a casu. He says that they differ most of all in the things which happen by nature, because chance has a place here but fortune does not. For when in the operations of nature something happens outside of nature, for example, when a six fingered person is born, we do not say that this happens by fortune, but rather because of that which is per se vain, i.e., by chance.
Et sic possumus accipere aliam differentiam inter casum et fortunam, quod eorum quae sunt a casu, causa est intrinseca, sicut eorum quae sunt a natura; eorum vero quae sunt a fortuna, causa est extrinseca, sicut et eorum quae sunt a proposito. And so we can take as another difference between chance and fortune the fact that the cause of those things which are by chance is intrinsic, just as the cause of those things which are by nature is intrinsic. But the cause of those things which are by fortune is extrinsic, just as the cause of those things which are from free choice is extrinsic.
Et ultimo concludit quod dictum est quid sit per se frustra, idest casus, et quid fortuna, et quomodo differant ab invicem. And he finally concludes that he has now explained what the per se vain or chance is, what fortune is, and how they differ from each other.
Deinde cum dicit: sed modorum causarum etc., ostendit ad quod genus causae casus et fortuna reducantur: 236. Next where he says, ‘Both belong...’ (198 a 2), he points out the genus of cause to which chance and fortune are reduced.
et primo ostendit propositum; secundo ex hoc improbat quandam opinionem superius positam, ibi: quoniam autem casus et cetera. First he states his position. Secondly, where he says, ‘Spontaneity and chance...’(198 a 5 #237), he disproves from this a certain opinion mentioned above [L7 #203].
Dicit ergo primo quod tam casus quam fortuna reducuntur ad genus causae moventis: quia casus et fortuna vel est causa eorum quae sunt a natura, vel eorum quae sunt ab intelligentia, ut ex dictis patet; unde cum natura et intelligentia sint causa ut unde est principium motus, etiam fortuna et casus ad idem genus reducuntur. Sed tamen, quia casus et fortuna sunt causae per accidens, eorum multitudo est indeterminata, ut supra dictum est. He says, therefore, first that both chance and fortune are reduced to the genus of the moving cause. For chance and fortune are causes either of those things which proceed from nature or of those things which proceed from intelligence, as is clear from what has been said. Hence, since nature and intelligence are causes as things from which motion begins, so fortune and chance also are reduced to the same genus. But since chance and fortune are per accidens causes, their number is indeterminate, as was said above [L9 #217,220].
Deinde cum dicit: quoniam autem casus etc., excludit opinionem ponentium fortunam vel casum esse causam caeli et omnium mundanorum. 237. Next where he says, ‘Spontaneity and chance...’ (198 a 5), he refutes the opinion of those who maintain that fortune and chance are the causes of the heavens and of all worldly things.
Et dicit quod quia casus et fortuna sunt causae per accidens eorum quorum intellectus et natura sunt causae per se; causa autem per accidens non est prior ea quae est per se, sicut nihil per accidens est prius eo quod est per se; sequitur quod casus et fortuna sint causae posteriores quam intellectus et natura. Unde si ponatur quod casus sit causa caeli, sicut quidam posuerunt, ut supra dictum est; sequetur quod intellectus et natura per prius sint causa aliquorum aliorum, et postea totius universi. He says that since chance and fortune are per accidens causes of those things of which intellect and nature are the per se causes, and since a per accidens cause is not prior to a per se cause, as nothing per accidens is prior to that which is per se, it follows that chance and fortune are causes which are posterior to intellect and nature. Hence if it should be held that chance is the cause of the heavens, as some maintained, as was said above [L7 #203] it would follow that intellect and nature are first of all causes of some other things and afterwards causes of the whole universe.
Causa etiam totius universi prior esse videtur quam causa alicuius partis universi; cum quaelibet pars universi ordinetur ad perfectionem universi. Hoc autem videtur inconveniens, quod aliqua alia causa sit prior quam ea quae est causa caeli: unde inconveniens est quod casus sit causa caeli. Moreover, the cause of the whole universe seems to be prior to the cause of some part of the universe, since any part of the universe is ordered to the perfection of the universe. But it seems to be inconsistent that some other cause is prior to that which is the cause of the heavens. Hence it is inconsistent that chance is the cause of the heavens.
Considerandum est autem quod si ea quae fortuito vel casualiter accidunt, idest praeter intentionem causarum inferiorum, reducantur in aliquam causam superiorem ordinantem ipsa; in comparatione ad illam causam non possunt dici fortuita vel casualia: unde illa causa superior non potest dici fortuna. 238. Furthermore we must consider that if those things which happen fortuitously or by chance, i.e., outside the intention of inferior causes, are reduced to some superior cause which orders them, then in relation to this latter cause they cannot be said to be fortuitous or by chance. Hence that superior cause cannot be called fortune.
Deinde cum dicit: quae autem sunt causae etc., ostendit quod causae non sunt plures iis quae sunt dictae. 239. Next where he says, ‘It is clear then...’ (198 a 14), he shows that the causes are not more than those mentioned.
Quod quidem manifestatur sic. Hoc quod dico propter quid, quaerit de causa; sed ad propter quid non respondetur nisi aliqua dictarum causarum; non igitur sunt plures causae quam quae dictae sunt. Et hoc est quod dicit, quod hoc quod dico propter quid, tot est secundum numerum, quot sunt causae praedictae. This is clarified as follows. The question ‘why’ asks for the cause. But only the above mentioned causes answer the question ‘why’. Therefore, the causes are not more than those which were mentioned. He says that the answers to the question ‘why’ are the same in number as the above mentioned causes.
Quandoque enim propter quid reducitur ultimo in quod quid est, idest in definitionem, ut patet in omnibus immobilibus, sicut sunt mathematica; in quibus propter quid reducitur ad definitionem recti vel commensurati vel alicuius alterius quod demonstratur in mathematicis. Cum enim definitio recti anguli sit, quod constituatur ex linea super aliam cadente, quae ex utraque parte faciat duos angulos aequales; si quaeratur propter quid iste angulus sit rectus, respondetur quia constituitur ex linea faciente duos angulos aequales ex utraque parte; et ita est in aliis. For sometimes the ‘why’ is reduced finally to what the thing is, i.e., to the definition, as is clear in all immobile things. The mathematicals are of this sort, in which the ‘why’ is reduced to the definition of the straight or of the commensurate, or of some other thing which is demonstrated in mathematics. Since a right angle is defined as that angle which is formed by the falling of one line upon another which makes of both parts two equal angles, then if it should be asked why an angle is a right angle, the reply would be because it is formed by a line making two equal angles from each part. And it is the same in the other instances.
Quandoque vero reducitur propter quid in primum movens; ut propter quid aliqui pugnaverant? Quia furati sunt: hoc enim est quod incitavit ad pugnam. Sometimes the ‘why’ is reduced to the first moving cause. Thus, why does someone fight? Because he has stolen. For this is what brought on the fight.
Quandoque autem reducitur in causam finalem; ut si quaeramus cuius causa aliqui pugnant, respondetur, ut dominentur. Sometimes it is reduced to the final cause, as if we should ask for the sake of what does someone fight, and the answer is that he might rule.
Quandoque autem reducitur in causam materialem; ut si quaeratur quare istud corpus est corruptibile, respondetur, quia compositum est ex contrariis. Sometimes it is reduced to the material cause, as when it is asked why this body is corruptible, and the answer is because it is composed of contraries.
Sic ergo patet has esse causas, et tot. Thus it is clear that these are the causes and they are just so many.
Necesse est autem quatuor esse causas. 240. Furthermore there must be four causes.
Quia cum causa sit ad quam sequitur esse alterius, esse eius quod habet causam, potest considerari dupliciter: uno modo absolute, et sic causa essendi est forma per quam aliquid est in actu; alio modo secundum quod de potentia ente fit actu ens. Et quia omne quod est in potentia, reducitur ad actum per id quod est actu ens; ex hoc necesse est esse duas alias causas, scilicet materiam, et agentem qui reducit materiam de potentia in actum. Actio autem agentis ad aliquid determinatum tendit, sicut ab aliquo determinato principio procedit: nam omne agens agit quod est sibi conveniens; id autem ad quod tendit actio agentis, dicitur causa finalis. Sic igitur necesse est esse causas quatuor. A cause is that upon which the existence of another follows. Now the existence of that which has a cause can be considered in two ways. First it is considered absolutely, and thus the cause of the existing is the form by which something is in act. Secondly it is considered insofar as a being comes to be in act from being in potency. And since everything which is in potency is reduced to act by that which is a being in act, it is necessary that there be two other causes, namely the matter and the agent which reduces the matter from potency to act. However, the action of the agent tends toward something determinate, and thus it proceeds from some determinate principle. For every agent does that which is suitable to it. But that toward which the action of the agent tends is called the final cause. Therefore, there must be four causes.
Sed quia forma est causa essendi absolute, aliae vero tres sunt causae essendi secundum quod aliquid accipit esse; inde est quod in immobilibus non considerantur aliae tres causae, sed solum causa formalis. But since the form is the cause of existing absolutely, the other three are causes of existence insofar as something receives existence. Hence in immobile things the other three causes are not considered, but only the formal cause is considered.

Lectio 11 (198 a 22-b 9)
NATURAL PHILOSOPHY DEMONSTRATES FROM ALL OF THE FOUR GENERA OF CAUSES
Chapter 7 cont.
ἐπεὶ δ' αἱ αἰτίαι τέτταρες, περὶ πασῶν τοῦ φυσικοῦ εἰδέναι, καὶ εἰς πάσας ἀνάγων τὸ διὰ τί ἀποδώσει φυσικῶς, τὴν ὕλην, τὸ εἶδος, τὸ κινῆσαν, τὸ οὗ ἕνεκα. Now, the causes being four, it is the business of the physicist to know about them all, and if he refers his problems back to all of them, he will assign the 'why' in the way proper to his science—the matter, the form, the mover, 'that for the sake of which'.
ἔρχεται δὲ τὰ τρία εἰς [τὸ] ἓν πολλάκις· τὸ μὲν γὰρ τί ἐστι καὶ τὸ οὗ ἕνεκα ἕν ἐστι, τὸ δ' ὅθεν ἡ κίνησις πρῶτον τῷ εἴδει ταὐτὸ τούτοις· ἄνθρωπος γὰρ ἄνθρωπον γεννᾷ The last three often coincide; for the 'what' and 'that for the sake of which' are one, while the primary source of motion is the same in species as these (for man generates man),
καὶ ὅλως ὅσα κινούμενα κινεῖ (ὅσα δὲ μή, οὐκέτι φυσικῆς· οὐ γὰρ ἐν αὑτοῖς ἔχοντα κίνησιν οὐδ' ἀρχὴν κινήσεως κινεῖ, ἀλλ' ἀκίνητα ὄντα· διὸ τρεῖς αἱ πραγματεῖαι, ἡ μὲν περὶ ἀκινήτων, ἡ δὲ περὶ κινουμένων μὲν ἀφθάρτων δέ, ἡ δὲ περὶ τὰ φθαρτά). and so too, in general, are all things which cause movement by being themselves moved; and such as are not of this kind are no longer inside the province of physics, for they cause motion not by possessing motion or a source of motion in themselves, but being themselves incapable of motion. Hence there are three branches of study, one of things which are incapable of motion, the second of things in motion, but indestructible, the third of destructible things.
ὥστε τὸ διὰ τί καὶ εἰς τὴν ὕλην ἀνάγοντι ἀποδίδοται, καὶ εἰς τὸ τί ἐστιν, καὶ εἰς τὸ πρῶτον κινῆσαν. The question 'why', then, is answered by reference to the matter, to the form, and to the primary moving cause.
περὶ γενέσεως γὰρ μάλιστα τοῦτον τὸν τρόπον τὰς αἰτίας σκοποῦσι, τί μετὰ τί γίγνεται, καὶ τί πρῶτον ἐποίησεν ἢ τί ἔπαθεν, καὶ οὕτως αἰεὶ τὸ ἐφεξῆς. διτταὶ δὲ αἱ ἀρχαὶ αἱ κινοῦσαι φυσικῶς, ὧν ἡ ἑτέρα οὐ φυσική· οὐ (198b.) γὰρ ἔχει κινήσεως ἀρχὴν ἐν αὑτῇ. τοιοῦτον δ' ἐστὶν εἴ τι κινεῖ μὴ κινούμενον, ὥσπερ τό τε παντελῶς ἀκίνητον καὶ [τὸ] πάντων πρῶτον For in respect of coming to be it is mostly in this last way that causes are investigated—'what comes to be after what? what was the primary agent or patient?' and so at each step of the series. Now the principles which cause motion in a physical way are two, of which one is not physical, as it has no principle of motion in itself. Of this kind is whatever causes movement, not being itself moved, such as (1) that which is completely unchangeable, the primary reality,
καὶ τὸ τί ἐστιν καὶ ἡ μορφή· τέλος γὰρ καὶ οὗ ἕνεκα· ὥστε ἐπεὶ ἡ φύσις ἕνεκά του, καὶ ταύτην εἰδέναι δεῖ, and (2) the essence of that which is coming to be, i.e. the form; for this is the end or 'that for the sake of which'. Hence since nature is for the sake of something, we must know this cause also.
καὶ πάντως ἀποδοτέον τὸ διὰ τί, οἷον ὅτι ἐκ τοῦδε ἀνάγκη τόδε (τὸ δὲ ἐκ τοῦδε ἢ ἁπλῶς ἢ ὡς ἐπὶ τὸ πολύ), We must explain the 'why' in all the senses of the term, namely, (1) that from this that will necessarily result ('from this' either without qualification or in most cases);
καὶ εἰ μέλλει τοδὶ ἔσεσθαι (ὥσπερ ἐκ τῶν προτάσεων τὸ συμπέρασμα), καὶ ὅτι τοῦτ' ἦν τὸ τί ἦν εἶναι, (2) that 'this must be so if that is to be so' (as the conclusion presupposes the premisses); (3) that this was the essence of the thing;
καὶ διότι βέλτιον οὕτως, οὐχ ἁπλῶς, ἀλλὰ τὸ πρὸς τὴν ἑκάστου οὐσίαν. and (4) because it is better thus (not without qualification, but with reference to the essential nature in each case).
Postquam philosophus determinavit de causis, hic ostendit quod naturalis ex omnibus causis demonstrat. 241. Having treated the causes, the Philosopher here shows that the natural philosopher demonstrates from all the causes.
Et circa hoc duo facit: primo dicit de quo est intentio; secundo exequitur propositum, ibi: sed tres in unam et cetera. Concerning this he makes two points. First he states his intention. Secondly, where he says, ‘The last three...’(198 a 25 #241), he explains his position.
Dicit ergo primo, quod cum quatuor sint causae, sicut supra dictum est, ad naturalem pertinet et omnes cognoscere, et per omnes naturaliter demonstrare, reducendo quaestionem propter quid in quamlibet dictarum quatuor causarum, scilicet formam, moventem, finem et materiam. Deinde cum dicit: sed tres in unam etc., exequitur propositum. He says, therefore, first that inasmuch as there are four causes, as was said above [L10 #239ff], it pertains to natural science both to know all of them and to demonstrate naturally through all of them by reducing the question ‘why’ to each of the aforementioned causes, i.e., the form, the moving cause, the end and the matter.
Et circa hoc duo facit: primo praemittit quaedam quae sunt necessaria ad propositum ostendendum; secundo probat propositum, ibi: quare propter quid et cetera. Next where he says, ‘The last three...’(198 a 25), he explains his position. Concerning this he makes two points. First he sets forth certain things which are necessary to clarify his position. Secondly, where he says, ‘The question...’ (198 a 32 #244), he proves his position.
Circa primum duo praemittit ad subsequentem probationem necessaria: quorum primum est de habitudine causarum ad invicem; secundum est de consideratione naturalis philosophiae, ibi: et omnino quaecumque mota et cetera. Concerning the first point he sets forth two things which are necessary for the proof of what follows. The first of these deals with the relationship of the causes among themselves. The second deals with the consideration of natural philosophy, and is given where he says’... and so too in general...’ (198 a 27 #243).
Dicit ergo primo quod multoties contingit quod tres causae concurrunt in unam, ita quod causa formalis et finalis sint una secundum numerum. 242. He says, therefore, first that it often happens that three of the causes combine into one, such that the formal cause and the final cause are one in number.
Et hoc intelligendum est de causa finali generationis, non autem de causa finali rei generatae. Finis enim generationis hominis est forma humana; non tamen finis hominis est forma eius, sed per formam suam convenit sibi operari ad finem. This must be understood to apply to the final cause of generation, not, however, to the final cause of the thing generated. For the end of the generation of man is the human form, but this form is not the end of man. Rather through this form man acts for his end.
Sed causa movens est eadem secundum speciem utrique earum. Et hoc praecipue in agentibus univocis, in quibus agens facit sibi simile secundum speciem, sicut homo generat hominem. In his enim forma generantis, quae est principium generationis, est idem specie cum forma generati, quae est generationis finis. In agentibus autem non univocis, alia est ratio: in his enim ea quae fiunt non possunt pertingere ad hoc quod consequantur formam generantis secundum eandem rationem speciei; sed participant aliquam similitudinem eius secundum quod possunt, ut patet in iis quae generantur a sole. Non igitur agens semper est idem specie cum forma, quae est finis generationis: nec iterum omnis finis est forma: et propter hoc signanter apposuit multoties. But the moving cause is the same as both of these according to species. And this is especially true in univocal agents in which the agent produces something like unto itself according to species, as man generates man. For in these cases the form of the generator, which is the principle of generation, is the same in species as the form of the generated, which is the end of the generation. However in non-univocal agents the species [ ratio ] is different. For in these cases the things which come to be cannot reach the point where they follow upon the form of the generator according to the same kind [ ratio ] of species. Rather they participate in some likeness to it, insofar as they are able, as is clear in those things which are generated by the sun. Therefore, the agent is not always the same in species with the form which is the end of generation, and furthermore, not every end is a form. And because of this it is significant that he said ‘often’.
Materia vero non est nec idem specie nec idem numero cum aliis causis; quia materia inquantum huiusmodi est ens in potentia, agens vero est ens in actu inquantum huiusmodi, forma vero vel finis est actus vel perfectio. The matter, however, is neither the same in species nor the same in number as the other causes. For matter as such is being in potency, whereas the agent as such is being in act, and the form or the end is act or perfection.
Deinde cum dicit: et omnino quaecumque etc., proponit secundum, quod est, de quibus scilicet consideret naturalis. 243. Next where he says, and so too...’ (198 a 27), he makes his second point which deals with the things which natural philosophy should treat.
Et dicit quod quaecumque moventia movent ita quod moveantur, pertinent ad considerationem naturalis; quae vero movent sed non moventur, non sunt de consideratione naturalis philosophiae, cuius est considerare de naturalibus, quae habent in se principium motus. Huiusmodi autem moventia non mota non habent in se principium motus, cum non moveantur, sed sint immobilia; et sic non sunt naturalia, et per consequens non sunt de consideratione naturalis philosophiae. He says that it pertains to natural philosophy to consider any movers which move in such a way that they are moved. Things, however, which move, but are not themselves moved, do not belong within the consideration of natural philosophy which properly considers natural things which have in themselves a principle of motion. For movers which are not themselves moved do not have in themselves a principle of motion, since they are not moved but are immobile. Thus, they are not natural things, and as a result do not come under the consideration of natural philosophy.
Unde patet quod tria sunt negotia, idest triplex est studium et intentio philosophiae, secundum tria genera rerum quae inveniuntur. Hence, it is clear that there are three branches of study, i.e., the study and intention of philosophy is threefold according to the three genera of things which are found.
Rerum enim quaedam sunt immobilia, et circa hoc est unum studium philosophiae; aliud vero studium eius est circa ea quae sunt mobilia sed incorruptibilia, sicut sunt corpora caelestia; tertium vero studium eius est circa mobilia et corruptibilia, sicut sunt corpora inferiora. For some things are immobile, and one philosophical study deals with them. Another philosophical study deals with things which are mobile but incorruptible, such as the celestial bodies. And there is a third philosophical study which deals with things which are mobile and corruptible, such as the inferior bodies.
Et primum quidem negotium pertinet ad metaphysicam; alia vero duo ad scientiam naturalem, cuius est determinare de omnibus mobilibus, tam corruptibilibus quam incorruptibilibus. The first of these studies pertains to metaphysics, while the other two pertain to natural science which treats all mobile things, both corruptible and incorruptible.
Unde male intellexerunt quidam, volentes haec tria reducere ad tres partes philosophiae, scilicet ad mathematicam, metaphysicam et physicam. Nam astronomia, quae videtur circa mobilia incorruptibilia considerationem habere, magis est naturalis quam mathematica, ut supra dictum est; inquantum enim applicat principia mathematica ad materiam naturalem, circa mobilia considerationem habet. Est igitur haec divisio secundum diversitatem rerum extra animam existentium, non secundum divisionem scientiarum accepta. Hence some have misunderstood this passage, desiring to reduce these three studies to the three parts of philosophy, namely, mathematics, metaphysics and physics. For astronomy, which seems to consider the incorruptible mobile things, belongs more to natural philosophy than to mathematics, as was said above [L3 #164-5]. For insofar as it applies mathematical principles to natural matter, it considers mobile things. Therefore, this division is taken according to the diversity of things existing outside the mind and not according to the division of the sciences.
Deinde cum dicit: quare propter quid etc., ostendit propositum.. 244. Next where he says, ‘The question “why”...’ (198 a 32), he sets forth his position.
Et circa hoc duo facit: primo ostendit quod ad naturalem pertinet considerare omnes causas et per eas demonstrare, quae duo supra proposuerat; secundo probat quaedam quae in hac probatione supponit, ibi: dicendum quidem igitur et cetera. Concerning this he makes two points. First he shows that it pertains to natural philosophy to consider all the causes and to demonstrate through them. These are the two points he has proposed above [#241]. Secondly, where he says, ‘We must explain...’ (198 b 10; L12 #250), he proves certain things which are assumed in this argument.
Circa primum duo facit: primo ostendit quod naturalis omnes causas considerat; secundo quod per omnes causas demonstrat, ibi: et penitus propter quid et cetera Concerning the first part he makes two points. First he shows that natural philosophy considers all the causes. Secondly, where he says, ‘We must explain...’ (198 b 4 #246) he shows that it demonstrates through all of them.
Circa primum duo facit: primo ostendit quod naturalis considerat materiam et formam et moventem; secundo quod considerat finem, ibi: et quod quid est et cetera. Concerning the first part he makes two points. First he shows that natural philosophy considers the matter and the form and the moving cause. Secondly, where he says, ‘... the essence of that...’(198 b 3 #246), he shows that it considers the end.
Circa primum duo facit: primo proponit quod intendit; secundo probat, ibi: de generatione et cetera. Concerning the first part he makes two points. First he states his intention, and secondly, he proves it, where he says, ‘For in respect of... (198 a 33 #245).
Concludit ergo primo ex praedictis quod assignatur propter quid a naturali, et reducendo in materiam, et reducendo in quod quid est, idest in formam, et reducendo in primum movens. First he concludes from what was said above that the ‘why’ is assigned to natural things by reference to the matter, and to what the thing is, i.e., the form, and to the first mover.
Deinde cum dicit: de generatione etc., probat propositum in hunc modum. 245. Next where he says, ‘For in respect of...’(198 a 33), he proves his position as follows.
Dictum est quod naturalis considerat ea quae moventur et generabilia et corruptibilia; quidquid ergo oportet considerare circa generationem, oportet considerari a naturali. Sed circa generationem oportet considerare formam, materiam et moventem. It has been said [#243] that natural philosophy considers those things which are moved, both the generable and the corruptible. Therefore, whatever should be considered about generation should be considered by natural philosophy. But with reference to generation one ought to consider the form, the matter, and the moving cause.
Qui enim volunt considerare circa generationem causas, hoc modo considerant: primo quid est id quod fit post aliquid, sicut ignis fit post aerem cum ex aere generatur ignis; et in hoc consideratur forma, per quam generatum est id quod est. Those who wish to consider the causes of generation consider them as follows. First we consider what it is that comes to be after something, as fire come to be after air, since fire is generated from air. And in this way the form, through which the generated is what it is, is considered.
Et iterum consideratur quid est quod primum fecit, idest quod primum movit ad generationem, et hoc est movens. Next we consider what it is that first makes [this), that is, we consider that which first moves to generation. And this is the moving cause.
Et iterum, quid est quod sustinuit, et hoc est subiectum et materia. Next we consider what it is that undergoes this change. And this is the subject and the matter.
Et non solum primum movens et primum subiectum considerantur circa generationem, sed etiam ea quae consequenter sunt. Et sic patet quod ad naturalem pertinet considerare formam, moventem et materiam. With reference to generation we consider not only the first mover and the first subject, but also those things which are consequent upon them. And thus it is clear that it pertains to natural philosophy to consider the form, the mover, and the matter.
Non tamen quaelibet moventia. Sunt enim principia moventia dupliciter, scilicet mota et non mota: quorum id quod non movetur non est naturale, quia non habet in se principium motus. Et tale est principium movens quod est penitus immobile et primum omnium, ut ostendetur in octavo. However, natural philosophy does not consider every mover. For there are two kinds of moving principles, namely, the moved and the non-moved. Now a mover that is not moved is not natural, because it does not have in itself a principle of motion. And such is the moving principle which is altogether immobile and the first of all movers, as will be shown in Book VIII [L9 & 13].
Deinde cum dicit: et quod quid est etc., ostendit quod naturalis considerat etiam finem. 246. Next where be says, the essence of that which...’ (198 b 3), he shows that natural philosophy also considers the end.
Et dicit quod etiam forma et quod quid est pertinet ad considerationem naturalis, secundum quod etiam finis est et cuius causa fit generatio. Dictum est enim supra quod forma et finis coincidunt in idem; et quia natura operatur propter aliquid, ut infra probabitur, necesse est quod ad naturalem pertineat considerare formam non solum inquantum est forma, sed etiam inquantum est finis. Si autem natura non ageret propter aliquid, consideraret quidem naturalis de forma inquantum est forma, sed non inquantum est finis. He says that the form and what the thing is also fall under the consideration of natural philosophy, insofar as the end is that for the sake of which the generation occurs. For it was said above [#242] that the form and the end coincide in the same thing. And since nature acts for the sake of something, as will be proven below [L12 #250], it must belong to natural philosophy to consider the form not only insofar as it is form but also insofar as it is the end. If, however, nature were not to act for the sake of something, then natural philosophy would consider form insofar as it is form, but not insofar as it is an end.
Deinde cum dicit: et penitus propter quid etc., ostendit quomodo naturalis demonstrat per omnes causas. 247. Next where he says, ‘We must explain...’ (198 b 4), he shows how natural philosophy demonstrates through all the causes.
Et primo quomodo demonstrat per materiam et moventem, quae sunt causae priores in generatione; secundo ostendit quomodo demonstrat per formam, ibi: et si hoc fieri debet etc.; tertio quomodo demonstrat per finem, ibi: et quia dignius et cetera. First he shows how it demonstrates through matter and the moving cause, which are the prior causes in generation. Secondly, where he says, ‘... that this must be so...’ (198 b 7 #248), he shows how it demonstrates through the form. Thirdly, where he says, ‘... because it is better...’ (198 b 8 #249), he shows how it demonstrates through the end.
Dicit ergo primo quod in naturalibus reddendum est propter quid penitus, idest secundum quodlibet genus causae: ut, quia hoc praecessit, sive illud sit materia sive movens, necesse est hoc esse consequenter; ut si aliquid generatum est ex contrariis, necesse est illud corrumpi, et si sol appropinquat ad polum Septentrionalem, necesse est fieri dies longiores et frigus diminui et calorem augeri apud eos qui habitant in parte Septentrionali. He says, therefore, first that in natural things the ‘why’ must be elaborated fully, i.e., in every genus of cause. Thus if something has gone before, whether it be the matter or the mover, then something necessarily follows. For example, if something is generated from contraries, it is necessary that the latter be corrupted, and if the sun approaches the north pole, the days must become longer, and cold must diminish and heat increase for those who dwell in the northern part.
Sed tamen considerandum est quod non semper ex praecedente materia vel movente necesse est aliquid subsequi; sed quandoque subsequitur aliquid simpliciter, idest ut semper, ut in his quae dicta sunt; quandoque autem ut frequenter, ut ex semine humano et movente in generatione, ut frequentius sequitur generatum habere duos oculos, quod tamen aliquando deficit. Et similiter ex hoc quod materia sic est disposita in corpore humano, accidit generari febrem propter putrefactionem ut frequentius; quandoque tamen impeditur. However, we must realize that it is not always necessary that something follows from a preceding matter or mover. Rather sometimes a thing follows simply or in every case, as in the things mentioned. But sometimes a thing follows in most instances, e.g., from human seed and a mover in generation, it follows in most instances that what is generated has two eyes, but at times this fails to happen. Similarly, because of the fact that matter is so disposed in the human body, it happens that a fever is frequently produced because of festering, but at times this is impeded.
Deinde cum dicit: et si hoc fieri debet etc., ostendit quomodo sit demonstrandum in naturalibus per causam formalem. 248. Next where he says, that this must be so...’ (198 b 7), he shows how in natural things demonstration must be made through the formal cause.
Ad cuius intelligentiam sciendum est, quod quando ex causis praecedentibus in generatione, scilicet ex materia et movente, sequitur aliquid ex necessitate, tunc ex eis potest sumi demonstratio, ut supra dictum est; non autem quando sequitur aliquid ut frequenter. Sed tunc debet sumi demonstratio ab eo quod est posterius in generatione, ad hoc quod aliquid ex necessitate sequatur ex altero, sicut ex propositionibus demonstrationis sequitur conclusio; ut procedamus demonstrando sic: si hoc debet fieri, ista et ista requiruntur; sicut si debet generari homo, necesse est quod sit semen humanum agens in generatione. In order to understand this, we must know that when something follows from the preceding causes in generation (i.e., from the matter and the mover) by necessity, then a demonstration can be established, as was said above [#247]. However, a demonstration cannot be established when something follows in most instances. But then a demonstration should be founded upon that which is posterior in generation in order that something might follow of necessity from another, just as the conclusion follows from the propositions of a demonstration. Thus let us proceed in demonstration as follows: if this should come to be, then this and that are required, for example, if man should be generated, it is necessary that human seed be an agent in the generation.
Si autem procedamus e converso: est semen humanum agens in generatione, non sequitur, ergo generabitur homo, sicut ex propositionibus sequitur conclusio. Sed hoc quod debet fieri, idest ad quod terminatur generatio, erat, secundum supra dicta, quod quid erat esse, idest forma. If, however, we proceed conversely by saying that ‘human seed is an agent in generation’, then the proposition ‘therefore man will be generated’, does not follow as a conclusion follows from propositions. But that which ought to come to be, i.e., that in which the generation is terminated, was (as was said above #242,246) ‘what the thing was to be’, i.e., the form.
Unde manifestum est quod quando secundum hunc modum demonstramus, si hoc debet fieri, demonstramus per causam formalem. Hence, it is clear that when we demonstrate according to this mode, i.e., ‘that “this must be so if that is to be so”’ (198 b 7), we demonstrate through the formal cause.
Deinde cum dicit: et quia dignius etc., ostendit quomodo naturalis demonstrat per causam finalem. 249. Next where he says, ‘...because it is better...’ (198 b 8), he shows how natural philosophy demonstrates through the final cause.
Et dicit quod etiam naturalis demonstrat aliquando aliquid esse, quia dignius est quod sic sit; sicut si demonstret quod dentes anteriores sunt acuti, quia melius est sic esse ad dividendum cibum, et natura facit quod melius est. Non tamen facit quod melius est simpliciter, sed quod melius est secundum quod competit substantiae uniuscuiusque: alioquin cuilibet animali daret animam rationalem, quae est melior quam anima irrationalis. He says that natural philosophy sometimes also demonstrates that something is true because it is better that it be so. For example, we might demonstrate that the front teeth are sharp because as such they are better for cutting food, and nature does what is better. Nature does not, however, do what is better simply, but what is better with reference to what belongs to each substance; otherwise nature would give a rational soul, which is better than an irrational soul, to each animal.

Lectio 12 (198 b 10-33)
THE ARGUMENT OF THOSE WHO DENY THAT NATURE ACTS FOR AN END
Chapter 8
Λεκτέον δὴ πρῶτον μὲν διότι ἡ φύσις τῶν ἕνεκά του αἰτίων, ἔπειτα περὶ τοῦ ἀναγκαίου, πῶς ἔχει ἐν τοῖς φυσικοῖς· εἰς γὰρ ταύτην τὴν αἰτίαν ἀνάγουσι πάντες, ὅτι ἐπειδὴ τὸ θερμὸν τοιονδὶ πέφυκεν καὶ τὸ ψυχρὸν καὶ ἕκαστον δὴ τῶν τοιούτων, ταδὶ ἐξ ἀνάγκης ἐστὶ καὶ γίγνεται· καὶ γὰρ ἐὰν ἄλλην αἰτίαν εἴπωσιν, ὅσον ἁψάμενοι χαίρειν ἐῶσιν, ὁ μὲν τὴν φιλίαν καὶ τὸ νεῖκος, ὁ δὲ τὸν νοῦν· We must explain then (1) that Nature belongs to the class of causes which act for the sake of something; (2) about the necessary and its place in physical problems, for all writers ascribe things to this cause, arguing that since the hot and the cold, etc., are of such and such a kind, therefore certain things necessarily are and come to be—and if they mention any other cause (one his 'friendship and strife', another his 'mind'), it is only to touch on it, and then good-bye to it.
ἔχει δ' ἀπορίαν τί κωλύει τὴν φύσιν μὴ ἕνεκά του ποιεῖν μηδ' ὅτι βέλτιον, ἀλλ' ὥσπερ ὕει ὁ Ζεὺς οὐχ ὅπως τὸν σῖτον αὐξήσῃ, ἀλλ' ἐξ ἀνάγκης (τὸ γὰρ ἀναχθὲν ψυχθῆναι δεῖ, καὶ τὸ ψυχθὲν ὕδωρ γενόμενον κατελθεῖν· τὸ δ' αὐξάνεσθαι τούτου γενομένου τὸν σῖτον συμβαίνει), ὁμοίως δὲ καὶ εἴ τῳ ἀπόλλυται ὁ σῖτος ἐν τῇ ἅλῳ, οὐ τούτου ἕνεκα ὕει ὅπως ἀπόληται, ἀλλὰ τοῦτο συμβέβηκεν—ὥστε τί κωλύει οὕτω καὶ τὰ μέρη ἔχειν ἐν τῇ φύσει, οἷον τοὺς ὀδόντας ἐξ ἀνάγκης ἀνατεῖλαι τοὺς μὲν ἐμπροσθίους ὀξεῖς, ἐπιτηδείους πρὸς τὸ διαιρεῖν, τοὺς δὲ γομφίους πλατεῖς καὶ χρησίμους πρὸς τὸ λεαίνειν τὴν τροφήν, ἐπεὶ οὐ τούτου ἕνεκα γενέσθαι, ἀλλὰ συμπεσεῖν· ὁμοίως δὲ καὶ περὶ τῶν ἄλλων μερῶν, ἐν ὅσοις δοκεῖ ὑπάρχειν τὸ ἕνεκά του. ὅπου μὲν οὖν ἅπαντα συνέβη ὥσπερ κἂν εἰ ἕνεκά του ἐγίγνετο, ταῦτα μὲν ἐσώθη ἀπὸ τοῦ αὐτομάτου συστάντα ἐπιτηδείως· ὅσα δὲ μὴ οὕτως, ἀπώλετο καὶ ἀπόλλυται, καθάπερ Ἐμπεδοκλῆς λέγει τὰ βουγενῆ ἀνδρόπρῳρα. ὁ μὲν οὖν λόγος, ᾧ ἄν τις ἀπορήσειεν, οὗτος, καὶ εἴ τις ἄλλος τοιοῦτός ἐστιν· A difficulty presents itself: why should not nature work, not for the sake of something, nor because it is better so, but just as the sky rains, not in order to make the corn grow, but of necessity? What is drawn up must cool, and what has been cooled must become water and descend, the result of this being that the corn grows. Similarly if a man's crop is spoiled on the threshing-floor, the rain did not fall for the sake of this—in order that the crop might be spoiled—but that result just followed. Why then should it not be the same with the parts in nature, e.g. that our teeth should come up of necessity—the front teeth sharp, fitted for tearing, the molars broad and useful for grinding down the food—since they did not arise for this end, but it was merely a coincident result; and so with all other parts in which we suppose that there is purpose? Wherever then all the parts came about just what they would have been if they had come be for an end, such things survived, being organized spontaneously in a fitting way; whereas those which grew otherwise perished and continue to perish, as Empedocles says his 'man-faced ox-progeny' did. Such are the arguments (and others of the kind) which may cause difficulty on this point.
Postquam philosophus ostendit quod naturalis demonstrat ex omnibus causis, hic manifestat quaedam quae supposuerat; scilicet quod natura agat propter finem, et quod in quibusdam necessarium non sit ex causis prioribus in esse, quae sunt movens et materia, sed ex causis posterioribus, quae sunt forma et finis. 250. Having shown that natural philosophy demonstrates from all the causes, the Philosopher here clarifies certain things which he had assumed, namely, that nature acts for an end and that in some things necessity is not from the causes which are prior in being (which are the matter and the moving cause), but from the posterior causes, which are the form and the end.
Et circa hoc duo facit: primo proponit quod intendit; secundo prosequitur propositum, ibi: habet autem oppositionem et cetera. Concerning this he makes two points. First he states his intention, and secondly, where he says, ‘A difficulty presents itself...’ (198 b 17 #251), he develops his position.
Dicit ergo primo, quod dicendum est primo quod natura est de numero illarum causarum quae propter aliquid agunt. Et hoc valet ad quaestionem de providentia. Ea enim quae non cognoscunt finem, non tendunt in finem nisi ut directa ab aliquo cognoscente, sicut sagitta a sagittante: unde si natura operetur propter finem, necesse est quod ab aliquo intelligente ordinetur; quod est providentiae opus. He says, therefore, first that it must be pointed. out that nature is among the number of causes which act for the sake of something. And this is important with reference to the problem of providence. For things which do not know the end do not tend toward the end unless they are directed by one who does know, as the arrow is directed by the archer. Hence if nature acts for an end, it is necessary that it be ordered by someone who is intelligent. This is the work of providence.
Post hoc autem dicendum est quomodo se habet necessarium in rebus naturalibus: utrum scilicet necessitas rerum naturalium semper sit ex materia, vel aliquando etiam ex materia et movente, vel aliquando ex forma et fine. After this it must be pointed out how necessity is present in natural things. Is the necessity of natural things always from the matter, or is it sometimes from the matter and the mover, or sometimes from the form and the end.
Et necessitas quaerendi haec est ista: quia omnes antiqui naturales reducunt effectus naturales in hanc causam, assignando rationem de eis, scilicet quod necesse est ea sic evenire propter materiam; utpote quia calidum natum est esse tale et facere talem effectum, et similiter frigidum, et omnia similia, necesse est fieri vel esse ea quae ex eis causantur. Et si aliqui antiquorum naturalium aliquam aliam causam tetigerint quam necessitatem materiae, non tamen habent unde gaudeant gloriantes; quia causis positis ab eis, scilicet intellectu, quem posuit Anaxagoras, et amicitia et lite, quas posuit Empedocles, non sunt usi nisi in generalibus quibusdam, sicut in constitutione mundi; in particularibus autem effectibus huiusmodi causas praetermiserunt. It is necessary to make this inquiry for the following reason. All of the ancient natural philosophers, when giving the reason [ ratio ] for natural effects, reduced such effects to this cause, i.e., that it is necessary for these things to happen because of matter. For example, since heat is by nature what it is and naturally produces a certain effect (and in like manner cold and other similar things), then those things which are caused by them must come to be or exist. And if some of the ancient natural philosophers touched upon some cause other than the necessity of matter, they have no reason for taking any glory from the fact. For after such causes were posited by them, e.g., intellect which Anaxagoras posited, and friendship and strife which Empedocles posited, they did not use them except in certain general instances, such as in the constitution of the world. But they omitted such causes when discussing particular effects.
Deinde cum dicit: habet autem oppositionem etc., exequitur propositum. 251. Next where he says, ‘A difficulty presents itself...’ (198 b 17), he develops his position.
Et primo inquirit utrum natura agat propter aliquid; secundo quomodo necessarium in rebus naturalibus inveniatur, ibi: quod autem est et cetera. First he asks whether nature acts for the sake of something, and secondly, where he says, ‘As regards what is “of necessity”...’ (199 b 34; L15 #269ff), how necessity is found in natural things.
Circa primum duo facit: primo ponit opinionem ponentium naturam non agere propter aliquid, et rationem eorum; secundo improbat eam, ibi: sed impossibile est ista et cetera. Concerning the first part he makes two points. First he gives the opinion and argument of those who hold that nature does not act for the sake of something. Secondly, he disproved this position, where he says, ‘Yet it is impossible...’ (198 b 34; L13 #255ff).
Circa primum sciendum quod ponentes naturam non agere propter aliquid, hoc confirmare nitebantur removentes id ex quo natura praecipue videtur propter aliquid operari. Hoc autem est quod maxime demonstrat naturam propter aliquid operari, quod ex operatione naturae semper invenitur aliquid fieri quanto melius et commodius esse potest, sicut pes hoc modo est factus a natura, secundum quod est aptus ad gradiendum; unde si recedat a naturali dispositione, non est aptus ad hunc usum; et simile est in ceteris. 252. Concerning the first point it must be noted that those who held that nature does not act for the sake of something tried to confirm their position by denying that in which nature is most clearly seen to act for the sake, of something. That which most strongly demonstrates that nature acts for the sake of something is the fact that in the operation of nature a thing is always found to come to be as good and as suitable as it can be. Thus, the foot is made in a certain way by nature so that it may be suitable for walking. Hence if it falls short of this natural disposition, it is not fit for this use. And the same is true of other instances.
Et quia contra hoc praecipue opponere nitebantur, ideo dicit quod potest opponi quod nihil prohibet naturam non facere propter aliquid, neque facere semper quod melius est. Invenimus enim quandoque quod ex aliqua operatione naturae provenit aliqua utilitas, quae tamen non est finis illius naturalis operationis, sed contingit sic evenire; sicut si dicamus quod Iupiter pluit, idest Deus vel natura universalis, non propter hunc finem, ut frumentum augmentet, sed pluvia provenit ex necessitate materiae. Oportet enim, inferioribus partibus ex propinquitate solis calefactis, resolvi vapores ex aquis; quibus sursum ascendentibus propter calorem, cum pervenerint ad locum ubi deficit calor propter distantiam a loco ubi reverberantur radii solis, necesse est quod aqua vaporabiliter ascendens congeletur ibidem, et congelatione facta, vapores vertantur in aquam; et cum aqua fuerit generata, necesse est quod cadat deorsum propter gravitatem: et cum hoc fit, accidit ut frumentum augeatur. Non tamen propter hoc pluit ut augeatur; quia similiter in aliquo loco frumentum destruitur propter pluviam, ut cum est collectum in area. Non tamen propter hoc pluit, ut destruatur frumentum, sed hoc casu accidit, pluvia cadente; And since they tried especially to oppose this point, Aristotle says that it can be objected that there is nothing to prevent nature from not acting for the sake of something nor from doing what is always better. For at times we find that from some operation of nature some utility results which nevertheless is not the end of that natural operation, but merely happens to occur. Thus, we might say that Jupiter rains, i.e., God or universal nature, but not for the purpose that grain should grow. Rather rain results from the necessity of matter. For it must be that in the lower regions, because of the closeness of the heat of the sun, vapours are drawn out from the water. Having been carried above because of the heat, when they arrive at the point where heat is lacking because of the distance from the place where the rays of the sun are reflected, it is necessary that the vaporized water which is going up freeze at that very point. When the freezing is completed, the vapours are changed into water. And when water has been generated, it must fall down because of its weight. And when this takes place, it happens that the grain grows. Now it does not rain so that grain might grow. For in the same way grain might be destroyed in some place because of rain, as when grain is gathered on a thrashing floor. Thus, rain does not fall in order to destroy grain, rather this happens by chance when rain falls.
et eodem modo videtur casu accidere quod frumentum crescat per accidens, pluvia cadente. And in the same way it seems to happen by chance that grain accidentally grows when rain falls.
Unde videtur quod nihil prohibeat sic etiam esse in partibus animalium, quae videntur esse sic dispositae propter aliquem finem: utpote quod aliquis dicat quod ex necessitate materiae contingit quod quidam dentes, anteriores scilicet, sint acuti et apti ad dividendum cibum, et maxillares sint lati et utiles ad conterendum cibum. Non tamen ita quod propter istas utilitates natura fecerit dentes tales vel tales: sed quia dentibus sic factis a natura propter necessitatem materiae sic decurrentis, accidit ut talem formam consequerentur, qua forma existente sequitur talis utilitas. Et similiter potest dici de omnibus aliis partibus, quae videntur habere aliquam determinatam formam propter aliquem finem. Hence it seems that there is nothing to prevent this from being true also in regard to animals, which seem to be disposed for the sake of some end. For example, one might say that because of the necessity of matter some teeth, i.e., the front teeth, happen to be sharp and suitable for cutting food, and the molars happen to be broad and useful for grinding food. Nevertheless, nature did not make the teeth such and so for the sake of these utilities. Rather after teeth have been made by nature in such a way as they develop from the necessity of matter, it is accidental that they acquired such a form. And once this form exists, this utility follows. And the same thing can be said of all other parts which seem to have some determinate form for the sake of some end.
Et quia posset aliquis dicere quod semper vel ut in pluribus tales utilitates consequuntur; quod autem est semper vel frequenter, conveniens est esse a natura: ideo ad hanc obiectionem excludendam, dicunt quod a principio constitutionis mundi, quatuor elementa convenerunt ad constitutionem rerum naturalium, et factae sunt multae et variae dispositiones rerum naturalium: et in quibuscumque omnia sic acciderunt apta ad aliquam utilitatem, sicut si propter hoc facta essent, illa tantum conservata sunt, eo quod habuerunt dispositionem aptam ad conservationem, non ab aliquo agente intendente finem, sed ab eo quod est per se vanum, idest a casu. Quaecumque vero non habuerunt talem dispositionem sunt destructa, et quotidie destruuntur; sicut Empedocles dixit a principio fuisse quosdam generatos, qui ex una parte erant boves, et ex alia parte erant homines. 253. But one might say that such utilities follow always or in many cases, and what is always or in most cases suitable exists by nature. In order to forestall this objection they say that from the beginning of the formation of the world the four elements were joined in the constitution of natural things, and thus the many and varied dispositions of natural things were produced. And in all these things only that which happened to be suitable for some utility, as if it were made for that utility, was preserved. For such things had a disposition which made them suitable for being preserved, not because of some agent intending an end, but because of that which is per se vain, i.e., by chance. On the other hand, whatever did not have such a disposition was destroyed, and is destroyed daily. Thus Empedocles said that in the beginning things which were part ox and part man were generated.
Haec est ergo ratio per quam aliquis dubitabit; vel si aliqua alia talis est. 254. Therefore, because of this argument, or because of some other similar argument, some will have a difficulty on this point.
Sed considerandum est in ista ratione, quod exemplum inconveniens accipit. Nam pluvia licet habeat necessariam causam ex parte materiae, tamen ordinatur ad finem aliquem, scilicet ad conservationem rerum generabilium et corruptibilium. Propter hoc enim est generatio et corruptio mutua in istis inferioribus, ut conservetur perpetuum esse in eis. Unde augmentum frumenti inconvenienter accipitur in exemplum: comparatur enim causa universalis ad effectum particularem. But in regard to this argument it must be noted that they use an unsuitable example. For although rain does have a necessary cause in regard to matter, it is nevertheless ordered to some end, namely, the conservation of things generable and corruptible. For in inferior things mutual generation and corruption are for this purpose: that perpetual existence be preserved in them. Hence the growth of grain is poorly taken as an example. For a universal cause is referred to a particular effect.
Sed et hoc etiam considerandum est, quod augmentum et conservatio terrae nascentium accidit ex pluvia ut in pluribus; sed corruptio accidit ut in paucioribus: unde licet pluvia non sit propter perditionem, non tamen sequitur quod non sit propter conservationem et augmentum. And it must also be noted that the growth and conservation of growing things on earth occur in most cases because of the rain, whereas their corruption occurs in few instances. Hence although rain is not for their destruction, it does not follow that it is not for their preservation and growth.

Lectio 13 (198 b 34-199 a 33)
IT IS DEMONSTRATED THAT NATURE ACTS FOR AN END
Chapter 8 cont.
ἀδύνατον δὲ τοῦτον ἔχειν τὸν τρόπον. ταῦτα μὲν γὰρ καὶ πάντα τὰ φύσει ἢ αἰεὶ οὕτω γίγνεται ἢ ὡς ἐπὶ τὸ πολύ, τῶν δ' ἀπὸ τύχης καὶ τοῦ αὐτομάτου οὐδέν. οὐ (199a.) γὰρ ἀπὸ τύχης οὐδ' ἀπὸ συμπτώματος δοκεῖ ὕειν πολλάκις τοῦ χειμῶνος, ἀλλ' ἐὰν ὑπὸ κύνα· οὐδὲ καύματα ὑπὸ κύνα, ἀλλ' ἂν χειμῶνος. εἰ οὖν ἢ ἀπὸ συμπτώματος δοκεῖ ἢ ἕνεκά του εἶναι, εἰ μὴ οἷόν τε ταῦτ' εἶναι μήτε ἀπὸ συμπτώματος μήτ' ἀπὸ ταὐτομάτου, ἕνεκά του ἂν εἴη. ἀλλὰ μὴν φύσει γ' ἐστὶ τὰ τοιαῦτα πάντα, ὡς κἂν αὐτοὶ φαῖεν οἱ ταῦτα λέγοντες. ἔστιν ἄρα τὸ ἕνεκά του ἐν τοῖς φύσει γιγνομένοις καὶ οὖσιν. Yet it is impossible that this should be the true view. For teeth and all other natural things either invariably or normally come about in a given way; but of not one of the results of chance or spontaneity is this true. We do not ascribe to chance or mere coincidence the frequency of rain in winter, but frequent rain in summer we do; nor heat in the dog-days, but only if we have it in winter. If then, it is agreed that things are either the result of coincidence or for an end, and these cannot be the result of coincidence or spontaneity, it follows that they must be for an end; and that such things are all due to nature even the champions of the theory which is before us would agree. Therefore action for an end is present in things which come to be and are by nature.
ἔτι ἐν ὅσοις τέλος ἔστι τι, τούτου ἕνεκα πράττεται τὸ πρότερον καὶ τὸ ἐφεξῆς. οὐκοῦν ὡς πράττεται, οὕτω πέφυκε, καὶ ὡς πέφυκεν, οὕτω πράττεται ἕκαστον, ἂν μή τι ἐμποδίζῃ. πράττεται δ' ἕνεκά του· καὶ πέφυκεν ἄρα ἕνεκά του. οἷον εἰ οἰκία τῶν φύσει γιγνομένων ἦν, οὕτως ἂν ἐγίγνετο ὡς νῦν ὑπὸ τῆς τέχνης· εἰ δὲ τὰ φύσει μὴ μόνον φύσει ἀλλὰ καὶ τέχνῃ γίγνοιτο, ὡσαύτως ἂν γίγνοιτο ᾗ πέφυκεν. ἕνεκα ἄρα θατέρου θάτερον. Further, where a series has a completion, all the preceding steps are for the sake of that. Now surely as in intelligent action, so in nature; and as in nature, so it is in each action, if nothing interferes. Now intelligent action is for the sake of an end; therefore the nature of things also is so. Thus if a house, e.g. had been a thing made by nature, it would have been made in the same way as it is now by art; and if things made by nature were made also by art, they would come to be in the same way as by nature. Each step then in the series is for the sake of the next;
ὅλως δὲ ἡ τέχνη τὰ μὲν ἐπιτελεῖ ἃ ἡ φύσις ἀδυνατεῖ ἀπεργάσασθαι, τὰ δὲ μιμεῖται. εἰ οὖν τὰ κατὰ τέχνην ἕνεκά του, δῆλον ὅτι καὶ τὰ κατὰ φύσιν· ὁμοίως γὰρ ἔχει πρὸς ἄλληλα ἐν τοῖς κατὰ τέχνην καὶ ἐν τοῖς κατὰ φύσιν τὰ ὕστερα πρὸς τὰ πρότερα. and generally art partly completes what nature cannot bring to a finish, and partly imitates her. If, therefore, artificial products are for the sake of an end, so clearly also are natural products. The relation of the later to the earlier terms of the series is the same in both.
μάλιστα δὲ φανερὸν ἐπὶ τῶν ζῴων τῶν ἄλλων, ἃ οὔτε τέχνῃ οὔτε ζητήσαντα οὔτε βουλευσάμενα ποιεῖ· ὅθεν διαποροῦσί τινες πότερον νῷ ἤ τινι ἄλλῳ ἐργάζονται οἵ τ' ἀράχναι καὶ οἱ μύρμηκες καὶ τὰ τοιαῦτα. κατὰ μικρὸν δ' οὕτω προϊόντι καὶ ἐν τοῖς φυτοῖς φαίνεται τὰ συμφέροντα γιγνόμενα πρὸς τὸ τέλος, οἷον τὰ φύλλα τῆς τοῦ καρποῦ ἕνεκα σκέπης. ὥστ' εἰ φύσει τε ποιεῖ καὶ ἕνεκά του ἡ χελιδὼν τὴν νεοττιὰν καὶ ὁ ἀράχνης τὸ ἀράχνιον, καὶ τὰ φυτὰ τὰ φύλλα ἕνεκα τῶν καρπῶν καὶ τὰς ῥίζας οὐκ ἄνω ἀλλὰ κάτω τῆς τροφῆς, φανερὸν ὅτι ἔστιν ἡ αἰτία ἡ τοιαύτη ἐν τοῖς φύσει γιγνομένοις καὶ οὖσιν. This is most obvious in the animals other than man: they make things neither by art nor after inquiry or deliberation. Wherefore people discuss whether it is by intelligence or by some other faculty that these creatures work,spiders, ants, and the like. By gradual advance in this direction we come to see clearly that in plants too that is produced which is conducive to the end-leaves, e.g. grow to provide shade for the fruit. If then it is both by nature and for an end that the swallow makes its nest and the spider its web, and plants grow leaves for the sake of the fruit and send their roots down (not up) for the sake of nourishment, it is plain that this kind of cause is operative in things which come to be and are by nature.
καὶ ἐπεὶ ἡ φύσις διττή, ἡ μὲν ὡς ὕλη ἡ δ' ὡς μορφή, τέλος δ' αὕτη, τοῦ τέλους δὲ ἕνεκα τἆλλα, αὕτη ἂν εἴη ἡ αἰτία, ἡ οὗ ἕνεκα. And since 'nature' means two things, the matter and the form, of which the latter is the end, and since all the rest is for the sake of the end, the form must be the cause in the sense of 'that for the sake of which'.
Posita opinione et ratione dicentium naturam non agere propter finem, hic improbat eam: et primo per rationes proprias; secundo per rationes sumptas ab iis ex quibus adversarii contrarium ostendere nitebantur, ibi: peccatum autem fit et cetera. 255. Having stated the opinion and argument of those who say that nature does not act for an end, he here disproves this position. He does this first through appropriate arguments, and secondly, where he says, ‘Now mistakes come to pass...’ (199 a 33; L14), through arguments taken from those things from which the opponents tried to prove the contrary position.
Circa primum ponit quinque rationes. Quarum prima: talis est. Omnia quae fiunt naturaliter, aut fiunt sicut semper, aut sicut frequenter: sed nihil eorum quae fiunt a fortuna vel per se vano, idest a casu, fit semper vel ut frequenter. Non enim dicimus quod a fortuna vel a casu fit, quod multoties pluat in hieme; sed diceremus esse a casu si forte multum plueret sub cane, id est in diebus canicularibus: et similiter non dicimus quod fit a casu quod cauma sit in diebus canicularibus; sed si hoc esset in hieme. Ex his duobus sic argumentatur. 256. Concerning the first point he sets forth five arguments. The first is as follows. Everything which happens naturally either happens in every instance or in most instances. But nothing which happens by fortune or by that which is per se vain, i.e., by chance, happens in every instance or in most instances. For we do not say that in the winter it rains frequently by fortune or by chance. But if it rains frequently during the dog days, we would say that this happens by chance. And in like manner, we do not say that it happens by chance that there is heat during the dog days, but only if this should happen during the winter.
Omnia quae fiunt, aut fiunt a casu, aut fiunt propter finem; quae enim accidunt praeter intentionem finis, dicuntur accidere casualiter: sed impossibile est ea quae fiunt semper vel frequenter, accidere a casu: ergo ea quae fiunt semper vel frequenter, fiunt propter aliquid. From these two points he argues as follows. Everything which happens either happens by chance or for the sake of an end. Now those things which happen outside the intention of an end are said to happen by chance. But it is impossible for those things which happen in every instance or in most instances to happen by chance. Therefore, those things which happen in every instance or in most instances happen for the sake of an end.
Sed omnia quae fiunt secundum naturam, fiunt vel semper vel frequenter, sicut etiam ipsi confitebantur: ergo omnia quae fiunt a natura, fiunt propter aliquid. Now whatever happens according to nature happens either in every instance or in most instances, as even they admitted. Therefore, whatever happens by nature happens for the sake of something.
Secundam rationem ponit ibi: amplius in quibuscumque etc.; et dicit quod in quibuscumque est aliquis finis, et priora et consequentia omnia aguntur causa finis. 257. He gives the second argument where he says, ‘Further, where a series...’(199 a 9). He says that there is an end for all things. That which is prior and all of its consequences are done for the sake of the end.
Hoc supposito sic argumentatur. Sicut aliquid agitur naturaliter, sic aptum natum est agi: hoc enim significat quod dico naturaliter, scilicet aptum natum. Et haec propositio convertitur, quia sicut aliquid aptum natum est agi, sic agitur: sed oportet apponere hanc conditionem, nisi aliquid impediat. Having assumed this he argues as follows. As something is done naturally, so is it disposed to be done. For ‘so disposed’ [aptum natum] means ‘naturally’. And this proposition is convertible, because as something is disposed to be done, so it is done. However, it is necessary to add this condition: unless it is impeded.
Accipiamus ergo primum, quod non habet instantiam, quod sicut aliquid agitur naturaliter, sic aptum natum est agi. Sed ea quae fiunt naturaliter, sic aguntur quod inducuntur ad finem; ergo sic apta nata sunt agi, ut sint propter finem: et hoc est naturam appetere finem, scilicet habere aptitudinem naturalem ad finem. Unde manifestum est quod natura agit propter finem. Therefore, let us agree that there is no impediment. Hence as something is done naturally, so is it disposed to be done. But things which happen naturally are done so that they lead to an end. Therefore, they are disposed to be done in such a way that they are for the sake of an end. And thus nature seeks an end, i.e., nature has a natural disposition for an end. Hence, it is clear that nature acts for the sake of an end.
Et hoc quod dixerat, manifestat per exemplum. He clarifies what he has said by an example.
Similiter enim ex prioribus pervenitur ad posteriora in arte et in natura: unde si artificialia, ut domus, fierent a natura, hoc ordine fierent quo nunc fiunt per artem; ut scilicet prius institueretur fundamentum, et postea erigerentur parietes, et ultimo superponeretur tectum. Hoc enim modo natura procedit in iis quae sunt terrae affixa, scilicet in plantis: quarum radices quasi fundamentum terrae infiguntur; stipes vero ad modum parietis elevatur in altum; frondes autem supereminent ad modum tecti. One proceeds from the prior to the posterior in the same way in both art and nature. Thus if artificial things, e.g., houses, were made by nature, they would be made according to the order in which they now are made by art. Thus the foundation would be constructed first, and afterwards the walls would be erected, and finally the roof would be placed on top. For nature proceeds this way in the things which are rooted in the earth, i.e., in plants. Their roots, like a foundation, are fixed in the earth, the trunk, after the manner of a wall, is raised on high, and the branches are on top like a roof.
Et similiter si ea quae fiunt a natura, fierent ab arte, hoc modo fierent sicut apta nata sunt fieri a natura; ut patet in sanitate, quam contingit fieri et ab arte et a natura; sicut enim natura sanat calefaciendo et infrigidando, ita et ars. And in like manner if the things which are produced by nature were made by art, they would be made according to the way they are disposed to be produced by nature. This is clear in regard to health, which happens to be produced by art and by nature. For as nature heals by heating and cooling, so also does art.
Unde manifestum est quod in natura est alterum propter alterum, scilicet priora propter posteriora, sicut et in arte. Hence it is clear that in nature one thing is for the sake of another, i.e., the prior is for the sake of the posterior. And the same is true of art.
Tertiam rationem ponit ibi: omnino autem ars etc.; et dicit quod ars quaedam facit, quae natura non potest facere, sicut domum et alia huiusmodi: in iis vero quae contingit fieri et ab arte et a natura, ars imitatur naturam, ut patet in sanitate, ut dictum est: unde si ea quae fiunt secundum artem, sunt propter finem, manifestum est quod etiam ea quae fiunt secundum naturam, propter finem fiunt, cum similiter se habeant priora ad posteriora in utrisque. 258. He gives the third argument where he says, ‘... and generally art...’ (199 a 16). He says that art makes certain things which nature cannot make’ such as a house and things of this sort. However, in regard to those things which happen to be produced by art and by nature, art imitates nature, as is clear in regard to health, as was said above [#257]. Hence, if things which are made according to art are for the sake of an end, it is clear that things which are made according to nature also are made for an end, since in each case the prior and the posterior are similarly related.
Potest tamen dici quod haec non est alia ratio a praemissa; sed complementum et explicatio ipsius. However, it can be said that this is not a different argument from the one already given, but is complementary to it and a clarification of it.
Quartam rationem ponit ibi: maxime autem manifestum etc., et sumitur haec ratio ab iis quae manifestius in natura propter aliquid operari videntur. 259. He gives the fourth argument where he says, ‘This is most obvious...’ (199 a 20). This argument is drawn from those things in nature which more obviously seem to act for the sake of something.
Unde dicit quod naturam operari propter aliquid maxime est manifestum in animalibus, quae neque operantur per artem, neque per inquisitionem, neque per deliberationem: et tamen manifestum est in operationibus eorum, quod propter aliquid operantur. Propter quod quidam dubitaverunt utrum aranei et formicae et huiusmodi animalia operentur per intellectum, vel per aliquod aliud principium. He says that it is most clear that nature acts for the sake of something when we consider animals which act neither through art, nor through inquiry, nor through deliberation. It is manifest in their operations that they act for the sake of something. Because of this some have wondered whether spiders and ants and animals of this sort act through intellect or through some other principle.
Sed tamen ex hoc fit manifestum quod non operantur ex intellectu, sed per naturam, quia semper eodem modo operantur; omnis enim hirundo similiter facit nidum, et omnis araneus similiter facit telam, quod non esset si ab intellectu et arte operarentur: non enim omnis aedificator similiter facit domum, quia artifex habet iudicare de forma artificiati, et potest eam variare. But because they always act in the same way, it is clear that they do not act by intellect, but by nature. For every swallow makes a nest in the same way, and every spider a web in the same way, which would not be the case if they acted by intellect and from art. For not every builder makes a house in the same way, because the artisan judges the form of the thing built and can vary it.
Ulterius autem procedenti de animalibus ad plantas, in eis etiam apparent quaedam esse facta et utilia ad finem, sicut folia sunt utilia propter cooperimentum fructuum. If we proceed beyond animals to plants, it is apparent among them that some things have been made and are useful for an end, as the leaves are useful as a covering for the fruit.
Unde si hoc est a natura et non ab arte, quod hirundo facit nidum et araneus telam, et plantae producunt folia gratia fructuum, et radices sunt in plantis non sursum, sed deorsum, ut accipiant nutrimentum a terra; manifestum est quod causa finalis invenitur in iis quae fiunt et sunt a natura, natura scilicet propter aliquid operante. Hence, if these things are due to nature and not to art, i.e., that the swallow makes a nest, and the spider a web, and the plants produce leaves for the sake of the fruit, and the roots of plants are not above, but below, so that they might take nourishment from the earth, it is clear that a final cause is found in things which come to be and are by nature, i.e., by-nature acting for the sake of something.
Quintam rationem ponit ibi: et quoniam natura dupliciter et cetera. 260. He gives the fifth argument where he says, ‘And since nature means...’ (199 a 30):
Dicit quod cum natura dicatur dupliciter, scilicet de materia et forma, et forma est finis generationis, ut supra dictum est; hoc autem est de ratione finis, ut propter ipsum fiant alia; sequitur quod esse et fieri propter aliquid, inveniatur in rebus naturalibus. He says that nature is used in two ways, i.e., for the matter and for the form. The form is the end of generation, as was said above [L11 #242]. And the nature [ ratio ] of an end is that other things come to be for the sake of it. Hence it follows that to be and to come to be for the sake of something should be found in natural things.

Lectio 14 (199 a 34-b 33)
HE DEMONSTRATES THAT NATURE ACTS FOR AN END
FROM THE EVIDENCE FROM WHICH SOME CONCLUDE TO THE OPPOSITE POSITION
Chapter 8 cont.
ἁμαρτία δὲ γίγνεται καὶ ἐν τοῖς κατὰ τέχνην (ἔγραψε γὰρ οὐκ ὀρθῶς ὁ γραμματικός, καὶ ἐπότισεν [οὐκ ὀρθῶς] ὁ ἰατρὸς τὸ φάρμακον), ὥστε δῆλον ὅτι ἐνδέχεται καὶ ἐν τοῖς κατὰ (199b.) φύσιν. εἰ δὴ ἔστιν ἔνια κατὰ τέχνην ἐν οἷς τὸ ὀρθῶς ἕνεκά του, ἐν δὲ τοῖς ἁμαρτανομένοις ἕνεκα μέν τινος ἐπιχειρεῖται ἀλλ' ἀποτυγχάνεται, ὁμοίως ἂν ἔχοι καὶ ἐν τοῖς φυσικοῖς, καὶ τὰ τέρατα ἁμαρτήματα ἐκείνου τοῦ ἕνεκά του. καὶ ἐν ταῖς ἐξ ἀρχῆς ἄρα συστάσεσι τὰ βουγενῆ, εἰ μὴ πρός τινα ὅρον καὶ τέλος δυνατὰ ἦν ἐλθεῖν, διαφθειρομένης ἂν ἀρχῆς τινὸς ἐγίγνετο, ὥσπερ νῦν τοῦ σπέρματος. Now mistakes come to pass even in the operations of art: the grammarian makes a mistake in writing and the doctor pours out the wrong dose. Hence clearly mistakes are possible in the operations of nature also. If then in art there are cases in which what is rightly produced serves a purpose, and if where mistakes occur there was a purpose in what was attempted, only it was not attained, so must it be also in natural products, and monstrosities will be failures in the purposive effort. Thus in the original combinations the 'ox-progeny' if they failed to reach a determinate end must have arisen through the corruption of some principle corresponding to what is now the seed.
ἔτι ἀνάγκη σπέρμα γενέσθαι πρῶτον, ἀλλὰ μὴ εὐθὺς τὰ ζῷα· καὶ τὸ "οὐλοφυὲς μὲν πρῶτα" σπέρμα ἦν. Further, seed must have come into being first, and not straightway the animals: the words 'whole-natured first...' must have meant seed.
ἔτι καὶ ἐν τοῖς φυτοῖς ἔνεστι τὸ ἕνεκά του, ἧττον δὲ διήρθρωται· πότερον οὖν καὶ ἐν τοῖς φυτοῖς ἐγίγνετο, ὥσπερ τὰ βουγενῆ ἀνδρόπρῳρα, οὕτω καὶ ἀμπελογενῆ ἐλαιόπρῳρα, ἢ οὔ; ἄτοπον γάρ· ἀλλὰ μὴν ἔδει γε, εἴπερ καὶ ἐν τοῖς ζῴοις. Again, in plants too we find the relation of means to end, though the degree of organization is less. Were there then in plants also 'olive-headed vine-progeny', like the 'man-headed ox-progeny', or not? An absurd suggestion; yet there must have been, if there were such things among animals.
ἔτι ἔδει καὶ ἐν τοῖς σπέρμασι γίγνεσθαι ὅπως ἔτυχεν· Moreover, among the seeds anything must have come to be at random.
ὅλως δ' ἀναιρεῖ ὁ οὕτως λέγων τὰ φύσει τε καὶ φύσιν· φύσει γάρ, ὅσα ἀπό τινος ἐν αὑτοῖς ἀρχῆς συνεχῶς κινούμενα ἀφικνεῖται εἴς τι τέλος· ἀφ' ἑκάστης δὲ οὐ τὸ αὐτὸ ἑκάστοις οὐδὲ τὸ τυχόν, ἀεὶ μέντοι ἐπὶ τὸ αὐτό, ἂν μή τι ἐμποδίσῃ. τὸ δὲ οὗ ἕνεκα, καὶ ὃ τούτου ἕνεκα, γένοιτο ἂν καὶ ἀπὸ τύχης, οἷον λέγομεν ὅτι ἀπὸ τύχης ἦλθεν ὁ ξένος καὶ λυ σάμενος ἀπῆλθεν, ὅταν ὥσπερ ἕνεκα τούτου ἐλθὼν πράξῃ, μὴ ἕνεκα δὲ τούτου ἔλθῃ. καὶ τοῦτο κατὰ συμβεβηκός (ἡ γὰρ τύχη τῶν κατὰ συμβεβηκὸς αἰτίων, καθάπερ καὶ πρότερον εἴπομεν), ἀλλ' ὅταν τοῦτο αἰεὶ ἢ ὡς ἐπὶ τὸ πολὺ γένηται, οὐ συμβεβηκὸς οὐδ' ἀπὸ τύχης· ἐν δὲ τοῖς φυσι κοῖς ἀεὶ οὕτως, ἂν μή τι ἐμποδίσῃ. But the person who asserts this entirely does away with 'nature' and what exists 'by nature'. For those things are natural which, by a continuous movement originated from an internal principle, arrive at some completion: the same completion is not reached from every principle; nor any chance completion, but always the tendency in each is towards the same end, if there is no impediment. The end and the means towards it may come about by chance. We say, for instance, that a stranger has come by chance, paid the ransom, and gone away, when he does so as if he had come for that purpose, though it was not for that that he came. This is incidental, for chance is an incidental cause, as I remarked before. But when an event takes place always or for the most part, it is not incidental or by chance. In natural products the sequence is invariable, if there is no impediment.
ἄτοπον δὲ τὸ μὴ οἴεσθαι ἕνεκά του γίγνεσθαι, ἐὰν μὴ ἴδωσι τὸ κινοῦν βουλευσάμενον. καίτοι καὶ ἡ τέχνη οὐ βουλεύεται· καὶ εἰ ἐνῆν ἐν τῷ ξύλῳ ἡ ναυπηγική, ὁμοίως ἂν τῇ φύσει ἐποίει· ὥστ' εἰ ἐν τῇ τέχνῃ ἔνεστι τὸ ἕνεκά του, καὶ ἐν τῇ φύσει. μάλιστα δὲ δῆλον, ὅταν τις ἰατρεύῃ αὐτὸς ἑαυτόν· τούτῳ γὰρ ἔοικεν ἡ φύσις. ὅτι μὲν οὖν αἰτία ἡ φύσις, καὶ οὕτως ὡς ἕνεκά του, φανερόν. It is absurd to suppose that purpose is not present because we do not observe the agent deliberating. Art does not deliberate. If the ship-building art were in the wood, it would produce the same results by nature. If, therefore, purpose is present in art, it is present also in nature. The best illustration is a doctor doctoring himself: nature is like that. It is plain then that nature is a cause, a cause that operates for a purpose.
Postquam ostendit philosophus per proprias rationes, quod natura agit propter aliquid, hic intendit hoc manifestare removendo ea per quae aliqui contrarium existimabant. 261. After the Philosopher has shown by appropriate arguments that nature acts for the sake of something, he here intends to make this clear by destroying those things through which some embraced the contrary position.
Et dividitur in tres partes, secundum tria ex quibus aliqui moveri videbantur ad hoc negandum. Secundum incipit ibi: omnino autem destruit etc.; tertium ibi: inconveniens autem et cetera. This section is divided into three parts according to the three things by which some seem to be moved to deny that nature acts for an end. The second part begins where he says, ‘But the person...’ (199 b 14 #267). The third part begins where he says, ‘It is absurd...’ (199 b 26 #268).
Primum autem ex quo aliqui moveri videbantur ad negandum naturam agere propter finem, ex hoc erat; quia videbant aliquando aliter accidere, sicut accidit in monstris, quae sunt peccata naturae. Unde etiam Empedocles posuit quod a principio constitutionis rerum, fuerunt producta quaedam, non habentia hanc formam et hunc ordinem qui nunc in natura communiter invenitur. 262. The first thing by which some seem to be moved to deny that nature acts for an end is the following. Sometimes we see things happen otherwise [than is customary], as happens in the case of monsters which are the errors of nature. Whence Empedocles held that at the beginning of the constitution of things certain things were produced which did not have this form and this order which is now commonly found in nature.
Ad hoc ergo excludendum inducit quatuor rationes. 263. He brings forth four arguments to overcome this difficulty.
Circa quarum primam ostendit quod licet ars agat propter aliquid, tamen in iis quae fiunt secundum artem, contingit fieri peccatum; quia aliquando grammaticus non recte scribit, et medicus quandoque potat aliquem medicinali potione non recte. First he shows that although art acts for the sake of something, still in things which are made by art error occurs. For sometimes the grammarian does not write correctly, and the doctor prescribes a drink as a medicinal potion incorrectly.
Unde manifestum est quod contingit peccatum esse etiam in iis quae sunt secundum naturam, quamvis natura propter aliquid operetur. In arte autem, eorum quae propter aliquid fiunt, quaedam fiunt secundum artem, et recte fiunt; quaedam autem sunt, in quibus artifex fallitur, non secundum artem agens: et in his contingit peccatum, arte propter aliquid agente. Si enim ars non ageret ad determinatum finem, qualitercumque ars operaretur, non esset peccatum; quia operatio artis aequaliter se haberet ad omnia. Hoc ipsum igitur quod in arte contingit esse peccatum, est signum quod ars propter aliquid operetur. Ita etiam contingit in naturalibus rebus; in quibus monstra sunt quasi peccata naturae propter aliquid agentis, inquantum deficit recta operatio naturae. Et hoc ipsum quod in naturalibus contingit esse peccatum, est signum quod natura propter aliquid agat. Hence it is clear that error occurs also in things which are by nature, even though nature acts for the sake of something. Of the things which are made by art for the sake of something, some are made according to art and are made correctly. There are other things, however, in which the artisan fails, not acting according to his art, and in these cases error occurs, even though the art is acting for the sake of something. For if art does not act for a determinate end, then there would be no error no matter how the art was performed. For the operation of the art would be equally related to all things. The very fact, then, that there happens to be error in art is a sign that art acts for the sake of something. The same thing also happens in natural things in which monsters are, as it were, the errors of nature acting for the sake of something insofar as the correct operation of nature is deficient. And this very fact that error occurs in natural things is a sign that nature acts for the sake of some thing.
Unde in substantiis quas in principio mundi Empedocles dixit esse constitutas bovigenas, idest ex media parte boves et ex media homines, si non poterant pervenire ad aliquem finem et terminum naturae, ut scilicet conservarentur in esse; non hoc fuit quia natura non hoc intendat, sed quia haec non possibilia salvari, generata sunt non secundum naturam, sed corrupto aliquo naturali principio; sicut nunc etiam accidit aliquos monstruosos partus generari propter corruptionem seminis. The same thing is true of those substances which Empedocles said were produced at the beginning of the world, such as the ‘ox-progeny’, i.e., half ox and half man. For if such things were not able to arrive at some end and final state of nature so that they would be preserved in existence, this was not because nature did not intend this [a final state], but because they were not capable of being preserved. For they were not generated according to nature, but by the corruption of some natural principle, as it now also happens that some monstrous offspring are generated because of the corruption of seed.
Secundam rationem ponit ibi: amplius necesse est etc.; quae talis est. 264. He gives the second argument where he says, ‘Further, seed must have...’ (199 b 8). The argument is as follows.
Ubicumque sunt determinata principia et determinatus ordo procedendi, ibi oportet esse determinatum finem propter quem alia fiant: sed in generatione animalium est determinatus ordo procedendi; quia oportet primum fieri semen, et non statim a principio est animal; et ipsum semen non statim est induratum, sed a principio est molle, et quodam ordine ad perfectionem tendit: ergo in generatione animalium est determinatus finis. Non ergo propter hoc accidunt monstra et peccata in animalibus, quia natura non agit propter aliquid. Wherever there are determinate principles and a determinate order of proceeding, there must be a determinate end for the sake of which other things come to be. But in the generation of animals there is a determinate order of proceeding. For it is necessary that seed come to be first, and there is no animal which exists immediately from the beginning. And the seed itself is not immediately hardened, but in the beginning it is soft and tends toward perfection in a certain order. Therefore, there is a determinate end in the generation of animals. Therefore, monsters and errors do not occur in animals because nature does not act for the sake of something.
Tertiam rationem ponit ibi: amplius et in plantis inest etc.; quae talis est. 265. He gives the third argument where he says, ‘Again in plants...’ (199 b 9). The argument is as follows.
Licet natura in plantis agat propter aliquid sicut in animalibus, tamen minus est dearticulatum, idest distinctum, in plantis; vel minus ex operationibus eorum colligi potest. Although nature acts for the sake of something in regard to plants as well as animals, this is less clear. Fewer things can be inferred from the operations of plants.
Si ergo propter hoc accidant peccata et monstra in animalibus, quia natura non agit propter aliquid, magis deberet accidere in plantis. Utrum igitur sicut fiunt in animalibus bovigena viriprora, ita fiant in plantis vitigena oleoprora, id est ex media parte olivae et media parte vites, vel non? Dicere enim quod fiant, videtur inconveniens: sed tamen oportet ita esse, si in animalibus contingit hac de causa, quia natura non agit propter aliquid. Non ergo ista de causa in animalibus contingit quia natura propter aliquid non agit. If, therefore, monsters and errors occur in animals because nature does not act for the sake of something, this should be even more true of plants. As the ‘man headed ox-progeny’ occurs in animals, does there also occur in plants an ‘olive-headed vine progeny’, i.e., half olive and half vine? It seems absurd to say that these things occur. Nevertheless this must be so if in regard to animals it is true that nature does not act for the sake of something. Therefore, in regard to animals it is not true that nature does not act for the sake of something.
Quartam rationem ponit ibi: adhuc oportuit etc.; quae talis est. 266. He gives the fourth argument where he says, ‘Moreover, among the seeds...’ (199 b 13). The argument is as follows.
Sicuti animalia generantur a natura, ita et semina animalium; si igitur accidit aliquid in generatione animalium qualitercumque contingit, et non quasi natura agente ad determinatum finem, sequetur etiam idem in seminibus; scilicet ut a quodcumque semen produceretur. Et hoc patet esse falsum: unde et primum falsum est. As animals are generated by nature, so also are the seeds of animals. If, therefore, what occurs in the generation of animals happens in any way whatsoever, and not by nature, as it were, acting for a determinate end, then the same would be true of seeds, i.e., that any sort of seed would be produced by any sort of thing. This is obviously false. Hence, the first [supposition) is also false.
Deinde cum dicit: omnino autem destruit etc., excludit secundum ex quo movebantur ad ponendum naturam non agere propter aliquid. 267. Next where he says, ‘But the person...’ (199 b 14), he destroys the second point by which some were moved to hold that nature does not act for the sake of something.
Videbatur enim hoc quibusdam, quia ea quae naturaliter accidunt, videntur ex prioribus principiis procedere, quae sunt agens et materia, et non ex intentione finis. This seemed true to some because things which happen naturally seem to proceed from the prior principles, which are the agent and the matter, and not from the intention for an end.
Sed ipse contrarium ostendit dicens, quod ille qui sic dicit, naturam scilicet non agere propter aliquid, destruit naturam et ea quae sunt secundum naturam. Haec enim dicuntur esse secundum naturam, quaecumque ab aliquo principio intrinseco moventur continue, quousque perveniant ad aliquem finem; non in quodcumque contingens, neque a quocumque principio in quemcumque finem, sed a determinato principio in determinatum finem: semper enim ab eodem principio proceditur in eundem finem, nisi aliquid impediat. Contingit autem id cuius causa fit aliquid, aliquando fieri a fortuna, quando non propter hoc agitur: sicut si aliquis extraneus veniat, et recedat balneatus, dicimus hoc esse a fortuna, eo quod ita fecit, se balneando, ac si propter hoc venisset, cum tamen propter hoc non venerit; unde secundum accidens est ipsum balneari (fortuna enim est de numero causarum secundum accidens, ut prius dictum est). Sed si semper aut frequenter ei venienti hoc accidat, non dicitur esse a fortuna. In rebus autem naturalibus, non per accidens sed semper sic est, nisi aliquid impediat: unde manifestum est quod determinatus finis, qui sequitur in natura, non sequitur a casu, sed ex intentione naturae. Ex quo patet quod contra rationem naturae est, dicere quod natura non agat propter aliquid. But Aristotle shows the contrary. He says that one who speaks in this manner, i.e., one who says that nature does not act for the sake of something, destroys nature and the things which are according to nature. For those things are said to be according to nature which are moved continuously by some intrinsic principle until they arrive at some end—not to some contingent end, and not from any principle to any end, but from a determinate principle to a determinate end. For progress is always made from the same principle to the same end, unless something impedes it. However, that for the sake of which something is done sometimes happens to occur by fortune, when [that which is done] is not done for the sake of this. For example, if some stranger should come and leave after he has bathed, we say this was by fortune. For he did not bathe himself as if he had come for this purpose, since he did not come for this. Hence his bathing is accidental (for fortune is a per accidens cause, as was said above; L8 #214). But if this should happen always or in most instances to him who comes, it would not be said to be by fortune. But in natural things events occur not per accidens but always, unless something should impede. Hence, it is clear that the determinate end which follows in nature does not follow by chance, but from the intention of nature. And from this it is clear that it is contrary to the meaning [ ratio ] of nature to say that nature does not act for the sake of something.
Deinde cum dicit: inconveniens autem est etc., excludit tertium ex quo aliquis opinari potest quod natura non agat propter aliquid. Videbatur enim quibusdam quod natura non agat propter aliquid, quia non deliberat. 268. Next where he says, ‘It is absurd...’(199 b 26), he destroys the third point by which some hold the opinion that nature does not act for the sake of something. For it seems to some that nature does not act for the sake of something because nature does not deliberate.
Sed philosophus dicit quod inconveniens est hoc opinari: quia manifestum est quod ars agit propter aliquid; et tamen manifestum est quod ars non deliberat. Nec artifex deliberat inquantum habet artem, sed inquantum deficit a certitudine artis: unde artes certissimae non deliberant, sicut scriptor non deliberat quomodo debeat formare litteras. Et illi etiam artifices qui deliberant, postquam invenerunt certum principium artis, in exequendo non deliberant: unde citharaedus, si in tangendo quamlibet chordam deliberaret, imperitissimus videretur. Ex quo patet quod non deliberare contingit alicui agenti, non quia non agit propter finem, sed quia habet determinata media per quae agit. Unde et natura, quia habet determinata media per quae agit, propter hoc non deliberat. In nullo enim alio natura ab arte videtur differre, nisi quia natura est principium intrinsecum, et ars est principium extrinsecum. Si enim ars factiva navis esset intrinseca ligno, facta fuisset navis a natura, sicut modo fit ab arte. Et hoc maxime manifestum est in arte quae est in eo quod movetur, licet per accidens, sicut de medico qui medicatur se ipsum: huic arti enim maxime assimilatur natura. But the Philosopher says that it is absurd to hold this opinion. For it is obvious, that art acts for the sake of something, yet it is also obvious that art does not deliberate. Nor does the artisan deliberate insofar as he has the art, but insofar as he falls short of the certitude of the art. Hence the most certain arts do not deliberate, as the writer does not deliberate how he should form letters. Moreover, those artisans who do deliberate, after they have discovered the certain principles of the art, do not deliberate in the execution. Thus one who plays the harp would seem most inexperienced if he should deliberate in playing any chord. And from this it is clear that an agent does not deliberate, not because he does not act for an end, but because he has the determinate means by which he acts. Hence since nature has the determinate means by which it acts, it does, not deliberate. For nature seems to differ from art only because nature is an intrinsic principle and art is an extrinsic principle. For if the art of ship building were intrinsic to wood, a ship would have been made by nature in the same way as it is made by art. And this is most obvious in the art which is in that which is moved, although per accidens, such as in the doctor who cures himself. For nature is very similar to this art.
Unde patet quod natura nihil est aliud quam ratio cuiusdam artis, scilicet divinae, indita rebus, qua ipsae res moventur ad finem determinatum: sicut si artifex factor navis posset lignis tribuere, quod ex se ipsis moverentur ad navis formam inducendam. Hence, it is clear that nature is nothing but a certain kind of art, i.e., the divine art, impressed upon things, by which these things are moved to a determinate end. It is as if the shipbuilder were able to give to timbers that by which they would move themselves to take the form of a ship.
Ultimo autem epilogando dicit, manifestum esse quod natura sit causa, et quod agat propter aliquid. Finally, he concludes by saying that it is clear that nature is a cause and that it acts for the sake of some thing.

Lectio 15 (199 b 34-200 b 9)
HOW NECESSITY IS FOUND IN NATURAL THINGS
Chapter 9
Τὸ δ' ἐξ ἀνάγκης πότερον ἐξ ὑποθέσεως ὑπάρχει ἢ καὶ ἁπλῶς; As regards what is 'of necessity', we must ask whether the necessity is 'hypothetical', or 'simple' as well.
νῦν μὲν γὰρ οἴονται τὸ ἐξ ἀνάγκης εἶναι (200a.) ἐν τῇ γενέσει ὥσπερ ἂν εἴ τις τὸν τοῖχον ἐξ ἀνάγκης γεγενῆσθαι νομίζοι, ὅτι τὰ μὲν βαρέα κάτω πέφυκε φέρεσθαι τὰ δὲ κοῦφα ἐπιπολῆς, διὸ οἱ λίθοι μὲν κάτω καὶ τὰ θεμέλια, ἡ δὲ γῆ ἄνω διὰ κουφότητα, ἐπιπολῆς δὲ μάλιστα τὰ ξύλα· κουφότατα γάρ. The current view places what is of necessity in the process of production, just as if one were to suppose that the wall of a house necessarily comes to be because what is heavy is naturally carried downwards and what is light to the top, wherefore the stones and foundations take the lowest place, with earth above because it is lighter, and wood at the top of all as being the lightest.
ἀλλ' ὅμως οὐκ ἄνευ μὲν τούτων γέγονεν, οὐ μέντοι διὰ ταῦτα πλὴν ὡς δι' ὕλην, ἀλλ' ἕνεκα τοῦ κρύπτειν ἄττα καὶ σώζειν. ὁμοίως δὲ καὶ ἐν τοῖς ἄλλοις πᾶσιν, ἐν ὅσοις τὸ ἕνεκά του ἔστιν, οὐκ ἄνευ μὲν τῶν ἀναγκαίαν ἐχόντων τὴν φύσιν, οὐ μέντοι γε διὰ ταῦτα ἀλλ' ἢ ὡς ὕλην, ἀλλ' ἕνεκά του, οἷον διὰ τί ὁ πρίων τοιοσδί; ὅπως τοδὶ καὶ ἕνεκα τουδί. τοῦτο μέντοι τὸ οὗ ἕνεκα ἀδύνατον γενέσθαι, ἂν μὴ σιδηροῦς ᾖ· ἀνάγκη ἄρα σιδηροῦν εἶναι, εἰ πρίων ἔσται καὶ τὸ ἔργον αὐτοῦ. ἐξ ὑποθέσεως δὴ τὸ ἀναγκαῖον, ἀλλ' οὐχ ὡς τέλος· ἐν γὰρ τῇ ὕλῃ τὸ ἀναγκαῖον, τὸ δ' οὗ ἕνεκα ἐν τῷ λόγῳ. Whereas, though the wall does not come to be without these, it is not due to these, except as its material cause: it comes to be for the sake of sheltering and guarding certain things. Similarly in all other things which involve production for an end; the product cannot come to be without things which have a necessary nature, but it is not due to these (except as its material); it comes to be for an end. For instance, why is a saw such as it is? To effect so-and-so and for the sake of so-and-so. This end, however, cannot be realized unless the saw is made of iron. It is, therefore, necessary for it to be of iron, it we are to have a saw and perform the operation of sawing. What is necessary then, is necessary on a hypothesis; it is not a result necessarily determined by antecedents. Necessity is in the matter, while 'that for the sake of which' is in the definition.
ἔστι δὲ τὸ ἀναγκαῖον ἔν τε τοῖς μαθήμασι καὶ ἐν τοῖς κατὰ φύσιν γιγνομένοις τρόπον τινὰ παραπλησίως· ἐπεὶ γὰρ τὸ εὐθὺ τοδί ἐστιν, ἀνάγκη τὸ τρίγωνον δύο ὀρθαῖς ἴσας ἔχειν· ἀλλ' οὐκ ἐπεὶ τοῦτο, ἐκεῖνο· ἀλλ' εἴ γε τοῦτο μὴ ἔστιν, οὐδὲ τὸ εὐθὺ ἔστιν. ἐν δὲ τοῖς γιγνομένοις ἕνεκά του ἀνάπαλιν, εἰ τὸ τέλος ἔσται ἢ ἔστι, καὶ τὸ ἔμπροσθεν ἔσται ἢ ἔστιν· εἰ δὲ μή, ὥσπερ ἐκεῖ μὴ ὄντος τοῦ συμπεράσματος ἡ ἀρχὴ οὐκ ἔσται, καὶ ἐνταῦθα τὸ τέλος καὶ τὸ οὗ ἕνεκα. ἀρχὴ γὰρ καὶ αὕτη, οὐ τῆς πράξεως ἀλλὰ τοῦ λογισμοῦ (ἐκεῖ δὲ τοῦ λογισμοῦ· πράξεις γὰρ οὐκ εἰσίν). ὥστ' εἰ ἔσται οἰκία, ἀνάγκη ταῦτα γενέσθαι ἢ ὑπάρχειν, ἢ εἶναι [ἢ] ὅλως τὴν ὕλην τὴν ἕνεκά του, οἷον πλίνθους καὶ λίθους, εἰ οἰκία· οὐ μέντοι διὰ ταῦτά ἐστι τὸ τέλος ἀλλ' ἢ ὡς ὕλην, οὐδ' ἔσται διὰ ταῦτα. ὅλως μέντοι μὴ ὄντων οὐκ ἔσται οὔθ' ἡ οἰκία οὔθ' ὁ πρίων, ἡ μὲν εἰ μὴ οἱ λίθοι, ὁ δ' εἰ μὴ ὁ σίδηρος· οὐδὲ γὰρ ἐκεῖ αἱ ἀρχαί, εἰ μὴ τὸ τρίγωνον δύο ὀρθαί. φανερὸν δὴ ὅτι τὸ ἀναγκαῖον ἐν τοῖς φυσικοῖς τὸ ὡς ὕλη λεγόμενον καὶ αἱ κινήσεις αἱ ταύτης. καὶ ἄμφω μὲν τῷ φυσικῷ λεκτέαι αἱ αἰτίαι, μᾶλλον δὲ ἡ τίνος ἕνεκα· Necessity in mathematics is in a way similar to necessity in things which come to be through the operation of nature. Since a straight line is what it is, it is necessary that the angles of a triangle should equal two right angles. But not conversely; though if the angles are not equal to two right angles, then the straight line is not what it is either. But in things which come to be for an end, the reverse is true. If the end is to exist or does exist, that also which precedes it will exist or does exist; otherwise just as there, if the conclusion is not true, the premiss will not be true, so here the end or 'that for the sake of which' will not exist. For this too is itself a starting-point, but of the reasoning, not of the action; while in mathematics the starting-point is the starting-point of the reasoning only, as there is no action. If then there is to be a house, such-and-such things must be made or be there already or exist, or generally the matter relative to the end, bricks and stones if it is a house. But the end is not due to these except as the matter, nor will it come to exist because of them. Yet if they do not exist at all, neither will the house, or the saw—the former in the absence of stones, the latter in the absence of iron—just as in the other case the premisses will not be true, if the angles of the triangle are not equal to two right angles. The necessary in nature, then, is plainly what we call by the name of matter, and the changes in it. Both causes must be stated by the physicist, but especially the end; for that is the cause of the matter, not vice versa;
αἴτιον γὰρ τοῦτο τῆς ὕλης, ἀλλ' οὐχ αὕτη τοῦ τέλους· καὶ τὸ τέλος τὸ οὗ ἕνεκα, καὶ ἡ ἀρχὴ ἀπὸ τοῦ ὁρισμοῦ καὶ τοῦ λόγου, ὥσπερ ἐν τοῖς κατὰ (200b.) τέχνην, ἐπεὶ ἡ οἰκία τοιόνδε, τάδε δεῖ γενέσθαι καὶ ὑπάρχειν ἐξ ἀνάγκης, καὶ ἐπεὶ ἡ ὑγίεια τοδί, τάδε δεῖ γενέσθαι ἐξ ἀνάγκης καὶ ὑπάρχειν—οὕτως καὶ εἰ ἄνθρωπος τοδί, ταδί· εἰ δὲ ταδί, ταδί. ἴσως δὲ καὶ ἐν τῷ λόγῳ ἔστιν τὸ ἀναγκαῖον. ὁρισαμένῳ γὰρ τὸ ἔργον τοῦ πρίειν ὅτι διαίρεσις τοιαδί, αὕτη γ' οὐκ ἔσται, εἰ μὴ ἕξει ὀδόντας τοιουσδί· οὗτοι δ' οὔ, εἰ μὴ σιδηροῦς. ἔστι γὰρ καὶ ἐν τῷ λόγῳ ἔνια μόρια ὡς ὕλη τοῦ λόγου. and the end is 'that for the sake of which', and the beginning starts from the definition or essence; as in artificial products, since a house is of such-and-such a kind, certain things must necessarily come to be or be there already, or since health is this, these things must necessarily come to be or be there already. Similarly if man is this, then these; if these, then those. Perhaps the necessary is present also in the definition. For if one defines the operation of sawing as being a certain kind of dividing, then this cannot come about unless the saw has teeth of a certain kind; and these cannot be unless it is of iron. For in the definition too there are some parts that are, as it were, its matter.
Postquam philosophus ostendit quod natura agit propter finem, hic procedit ad inquirendum de secunda quaestione, scilicet quomodo necessitas inveniatur in rebus naturalibus. 269. Having shown that nature acts for an end, the Philosopher here proceeds to inquire into the second question, i.e., how necessity is found in natural things.
Et circa hoc tria facit: primo movet quaestionem; secundo ponit aliorum opinionem, ibi: nunc quidam enim etc.; tertio determinat veritatem, ibi: sed tamen non sine his et cetera. Concerning this he makes three points. First he raises the question. Secondly, where he says, ‘The current view...’ (199 b 35 #271), he sets forth the opinion of others. Thirdly, where he says, ‘Whereas, though the wall...’ (200 a 5 #272), he determines the truth.
Quaerit ergo primo utrum in rebus naturalibus sit necessarium simpliciter, idest absolute, aut necessarium ex conditione, sive ex suppositione. 270. He asks, therefore, whether in natural things there is a simple necessity, i.e., an absolute necessity, or a necessary by condition or by supposition.
Ad cuius evidentiam sciendum est, quod necessitas quae dependet ex causis prioribus, est necessitas absoluta, ut patet ex necessario quod dependet ex materia. Animal enim esse corruptibile, est necessarium absolute: consequitur enim ad hoc quod est animal, esse compositum ex contrariis. In order to understand this, it must be noted that the necessity which depends upon prior causes is an absolute necessity, as is clear from the the necessity which depends upon matter. That an animal is corruptible is absolutely necessary. For to be composed of contraries is a consequence of being an animal.
Similiter etiam quod habet necessitatem ex causa formali, est necessarium absolute; sicut hominem esse rationalem, aut triangulum habere tres angulos aequales duobus rectis, quod reducitur in definitionem trianguli. In like manner, that which has necessity from the formal cause is also absolutely necessary. For example, man is rational, or a triangle has three angles equal to two right angles, which is reduced to the definition of triangle.
Et similiter quod habet necessitatem ex causa efficiente, est necessarium absolute; sicut necessarium est esse alternationem noctis et diei propter motum solis. Similarly, that which has necessity from the efficient cause is absolutely necessary. Thus because of the motion of the sun it is necessary that day and night alternate.
Quod autem habet necessitatem ab eo quod est posterius in esse, est necessarium ex conditione, vel suppositione; ut puta si dicatur, necesse est hoc esse si hoc debeat fieri: et huiusmodi necessitas est ex fine, et ex forma inquantum est finis generationis. But that which has necessity from that which is posterior in existence is necessary upon condition, or by supposition. For example, it might be said that it is necessary that this be if this should come to be. Necessity of this kind is from the end and from the form insofar as it is the end of generation.
Quaerere igitur utrum in rebus naturalibus sit necessarium simpliciter aut ex suppositione, nihil aliud est quam quaerere utrum in rebus naturalibus necessitas inveniatur ex fine, aut ex materia. Therefore to ask whether in natural things there is a simple necessity or a necessity by supposition is nothing else than to ask whether necessity is found in natural things from the end or from the matter.
Deinde cum dicit: nunc quidam enim etc., ponit aliorum opinionem. 271. Next where he says, ‘The current view...’ (199 b 35), he gives the opinion of others.
Et dicit quod quidam opinantur quod generatio rerum naturalium proveniat ex necessitate absoluta materiae; ut puta si aliquis diceret quod paries aut domus taliter sit ex necessitate materiae, eo quod gravia nata sunt deorsum ferri, levia vero supereminere: et propter hoc lapides graves et duri remanent in fundamento, terra vero lapidibus superponitur tanquam levior, ut patet in parietibus constructis ex lateribus, qui ex terra conficiuntur; sed in summo ponuntur ligna, scilicet in tecto, quae sunt maxime levia. Ita etiam existimabant dispositiones rerum naturalium provenisse tales ex necessitate materiae; ut puta si dicatur quod homo habet pedes inferius et manus superius propter gravitatem aut levitatem humorum. He says that some are of the opinion that the generation of natural things arises from an absolute necessity of matter. For example, one might say that a wall or a house is such as it is by the necessity of matter because heavy things are disposed to move downward and light things to rise above. And because of this the heavy and hard stones remain in the foundation, while earth being lighter rises above the stones, as is clear in walls constructed of tiles which are made of earth. But the timbers which are the lightest are placed at the highest point, i.e., at the roof. Thus they thought that the dispositions of natural things have come to be such as they are from the necessity of matter. For example, it might be said that a man has feet below and hands above because of the heaviness or lightness of humours.
Deinde cum dicit: sed tamen non sine his quidem etc., determinat veritatem. 272. Next where he says, ‘Whereas, though the wall...’ (200 a 5), he determines the truth.
Et circa hoc duo facit: primo ostendit qualiter sit necessitas in rebus naturalibus; secundo assimilat necessitatem rerum naturalium necessitati quae est in scientiis demonstrativis, ibi: est autem necessarium et cetera. Concerning this he makes two points. First he shows what sort of necessity there is in natural things. Secondly, where he says, ‘Necessity in mathematics...’ (200 a 15 #273), he compares the necessity of natural things to the necessity which is in the demonstrative sciences.
Dicit ergo primo quod, licet inconveniens videatur dicere quod in rebus naturalibus sit talis dispositio propter necessitatem materiae, sicut et apparet hoc esse inconveniens in rebus artificialibus, de quibus exemplum positum est; non tamen est talis dispositio facta in rebus naturalibus et artificialibus, sine principiis materialibus habentibus aptitudinem ad talem dispositionem: non enim domus convenienter constaret, nisi graviora in fundamento ponerentur, et leviora superius. He says, therefore, first that granting that it seems absurd to say that there is such a disposition in natural things because of the matter, it also appears absurd to say that this is true of artificial things, an example of which has already been given [#271]. However, such a disposition is not produced in natural things and in artificial things unless the material principles have an aptitude for such a disposition. For a house would not stand well unless the heavier materials were placed in the foundation and the lighter materials above.
Non tamen dicendum est quod propter hoc domus sic sit disposita quod una pars eius sit inferius et alia superius, propter hoc, id est propter gravitatem aut levitatem quarundam partium; nisi secundum quod haec praepositio propter dicit causam materialem, quae propter formam est: sed partes domus sic sunt dispositae propter finem, qui est cooperire et salvare homines a caumate et pluviis. However, it must not be said because of this that the house is so disposed that one part of it is below and another above. [I say] ‘because of this’, i.e., because of the heaviness or lightness of certain parts, (except insofar as the term ‘because of ‘refers to the material cause, which is for the sake of the form). Rather the parts of a house are so disposed for the sake of an end, which is to shelter and protect men from the heat and the rain.
Et sicuti est in domo, similiter est in omnibus aliis, in quibuscumque contingit agere propter aliquid: in omnibus enim huiusmodi non consequuntur dispositiones generatorum aut factorum sine principiis materialibus, quae habent necessariam materiam, per quam apta, nata sunt sic disponi. And just as it is with a house, so it is with all other things in which something happens to act for the sake of something. For in all things of this sort the dispositions of what is generated or made do not follow without material principles, which have a necessary matter by which they are apt to be so disposed.
Non tamen res factae aut generatae sic disponuntur propter hoc, quod principia materialia sunt talia, nisi sicut ly propter dicit causam materialem; sed sic disponuntur propter aliquem finem, et principia materialia quaeruntur ut sint apta huic dispositioni, quam requirit finis, ut patet in serra. Est enim serra huiusmodi, idest talis dispositionis aut formae: quare oportet quod sit talis, idest ut habeat talem materiam: et est huiusmodi, idest talis dispositionis aut formae, propter hoc, idest propter aliquem finem. Sed tamen iste finis, qui est sectio, non posset provenire nisi esset ferrea: necessarium est ergo serram esse ferream, si debeat esse serra, et si debeat esse eius finis, quod est opus ipsius. However, the things made or generated are not so disposed because the material principles are such, unless the term ‘because of ‘refers to the material cause. Rather they are so disposed because of the end. And the material principles seek to be apt for this disposition which the end requires, as is clear in a saw. For a saw has a certain disposition or form. And for this reason it must have such a matter. And it has a certain disposition or form because of some end. However, this end, which is cutting, could not be achieved unless the saw were of iron. Therefore, it is necessary that a saw be iron, if there must be a saw and if it must be for this end, which is its operation.
Sic igitur patet quod in rebus naturalibus est necessarium ex suppositione, sicut et in rebus artificialibus: sed non ita quod id quod est necessarium, sit sicut finis; quia id quod necessarium est, ponitur ex parte materiae; sed ex parte finis ponitur ratio necessitatis. Non enim dicimus quod necessarium sit esse talem finem, quia materia talis est; sed potius e converso, quia finis et forma talis futura est, necesse est materiam talem esse. Et sic necessitas ponitur ad materiam, sed ratio necessitatis ad finem. Thus it is clear that there is a necessity by supposition in natural things, just as there is such a necessity in artificial things, but not such that that which is necessary is the end. For that which is necessary is posited on the part of the matter, whereas on the part of the end the reason [ ratio ] for the necessity is posited. For we do not say that there must be such an end because the matter is such. Rather we say conversely that since the end and the future form are such, the matter must be such. And so the necessity is placed in the matter, but the reason [ ratio ] for the necessity is placed in the end.
Deinde cum dicit: est autem necessarium etc., assimilat necessitatem quae est in generatione rerum naturalium, necessitati quae est in scientiis demonstrativis. 273. Next where he says, ‘Necessity in mathematics...’ (200 a 15), he compares the necessity which is in the generation of natural things to the necessity which is in the demonstrative sciences.
Et primo quantum ad ordinem necessitatis; secundo quantum ad id quod est necessitatis principium, ibi: et finis quod est et cetera. He does this first with reference to the order of necessity, and secondly with reference to that which is the principle of the necessity, where he says, ‘... and the end...’ (200 a 34 #274).
Dicit ergo primo quod aliquo modo similiter invenitur necessarium in scientiis demonstrativis, et in iis quae generantur secundum naturam. He says, therefore, first that in a certain respect necessity is found in the demonstrative sciences in the same way that it is found in things which are generated according to nature.
Invenitur enim in scientiis demonstrativis necessarium a priori, sicut si dicamus quod quia definitio recti anguli est talis, necesse est triangulum esse talem, scilicet habere tres angulos aequales duobus rectis. Ex illo ergo priori quod assumitur ut principium, provenit ex necessitate conclusio. For an ‘a priori’ necessity is found in the demonstrative sciences, as when we say that since the definition of a right angle is such, it is necessary that a triangle be such and so, i.e., that it have three angles equal to two right angles. Therefore, from that which is first assumed as a principle the conclusion arises by necessity.
Sed non sequitur e converso, si conclusio est, quod principium sit; quia aliquando ex falsis propositionibus potest syllogizari conclusio vera. Sed tamen sequitur quod si conclusio non est, quod neque principium praemissum sit; quia falsum nunquam syllogizatur nisi ex falso. But the converse does not follow, i.e., if the conclusion is, then the principle is. For sometimes a true conclusion can be drawn from false propositions. But it does follow that if the conclusion is not true, then, neither is the given premise true. For a false conclusion is drawn only from a false premise.
Sed in iis quae fiunt propter aliquid, sive secundum artem sive secundum naturam, e converso se habet: quia si finis erit aut est, necesse est quod est ante finem futurum esse aut esse. Si vero id quod est ante finem non est, neque finis erit: sicut in demonstrativis, si non sit conclusio, non erit principium. But in things which are made for the sake of something, either according to art or according to nature, this converse does obtain. For if the end either will be or is, then it is necessary that what is prior to the end either will have been or is. If, however, that which is prior to the end is not, then the end will not be, just as in demonstrative sciences, if the conclusion is not true, the premise will not be true.
Sic igitur patet quod in iis quae fiunt propter finem, eundem ordinem tenet finis, quem tenet principium in demonstrativis. Et hoc ideo quia etiam finis est principium, non quidem actionis, sed ratiocinationis; quia a fine incipimus ratiocinari de iis quae sunt ad finem: in demonstrativis autem non attenditur principium actus, sed ratiocinationis; quia in demonstrativis non sunt actiones, sed ratiocinationes tantum. Unde convenienter finis in iis quae fiunt propter finem, tenet locum principii quod est in demonstrativis. Unde similitudo est utrobique; quamvis e converso se videatur habere propter hoc quod finis est ultimum in actione, quod in demonstratione non est. It is clear, therefore, that in things which come to be for the sake of an end the end holds the same order which the premise holds in demonstrative sciences. This is so because the end also is a principle, not indeed of action, but of reasoning. For from the end we begin to reason about those things which are the means to the end. In demonstrative sciences, however, a principle of action is not considered, but only a principle of reasoning, because there are no actions in demonstrative sciences, but only reasonings. Hence in things which are done for the sake of an end, the end properly holds the place which the premise holds in demonstrative sciences. Hence, there is a similarity on both sides, even though they seem to be related conversely because of the fact that the end is last in action, which does not pertain to demonstration.
Sic igitur concludit quod si debeat fieri domus, quod est finis generationis, necesse est hoc fieri aut praeexistere, scilicet materiam, quae propter finem est; sicut lateres et lapides necesse est praeexistere si domus debet fieri. Non tamen quod finis sit propter materiam, sed non erit si materia non sit; sicut domus non erit si non sint lapides, et serra non erit si non fuerit ferrum: quia et in scientiis demonstrativis principia non sunt si conclusio non sit, quae assimilatur iis quae sunt ad finem, sicut principium fini, sicut dictum est. Therefore, he concludes that if a house which is the end of a generation, is to come to be, it is necessary that the matter which is for the sake of this end come to be and pre-exist. Thus, tiles and stones must exist first if a house is to come to be. This does not mean that the end is for the sake of the matter, but rather that the end will not be if the matter does not exist. Thus, there will be no house if there are no stones, and there will be no saw if there were no iron. For just as in demonstrative sciences the premises are not true if the conclusion, which is similar to things which are for an end, is not true, so also is the beginning related to the end, as was said.
Sic igitur manifestum est quod in rebus naturalibus dicitur esse necessarium, quod se habet per modum materiae vel materialis motus: et ratio huius necessitatis est ex fine; propter finem enim necessarium est esse materiam talem. Thus it is clear that in natural things that is said to be necessary which is material or is a material motion. And the reason [ ratio ] for this necessity is taken from the end, for it is necessary for the sake of the end that the matter be such.
Et naturalis quidem assignare debet utramque causam, scilicet materialem et finalem, sed magis finalem, quia finis est causa materiae, sed non e converso. Non enim finis est talis quia materia est talis: sed potius materia est talis quia finis est talis, ut dictum est. And one ought to determine both causes of a natural thing, i.e., both the material and the final cause, but especially the final cause, because the end is the cause of the matter, but not conversely. For the end is not such as it is because the matter is such, but rather the matter is such as it is because the end is such, as was said above [#272].
Deinde cum dicit: et finis, quod est etc., assimilat necessitatem naturalis generationis necessitati scientiarum demonstrativarum, quantum ad id quod est necessitatis principium. 274. Next where he says, ‘...and the end...’ (200 a 34), he compares the necessity of natural generation to the necessity of the demonstrative sciences with respect to that which is the principle of the necessity.
Manifestum est enim quod in scientiis demonstrativis, principium demonstrationis est definitio: et similiter finis, qui est principium et ratio necessitatis in iis quae fiunt secundum naturam, est quoddam principium sumptum a ratione et definitione; finis enim generationis est forma speciei, quam significat definitio. It is clear that in demonstrative sciences the definition is the principle of the demonstration. And in like manner the end, which is the principle and reason [ ratio ] for necessity in things which come to be according to nature, is a sort of principle taken by reason and by definition. For the end of generation is the form of the species which the definition signifies.
Et hoc etiam patet in artificialibus: sicut enim demonstrator in demonstrando accipit definitionem ut principium, ita et aedificator in aedificando, et medicus in sanando; ut quia talis est definitio domus, oportet hoc fieri et esse ad hoc quod domus fiat: et quia haec est definitio sanitatis, oportet hoc fieri ad hoc quod aliquis sanetur: et si haec et illa, quousque perveniatur ad illa quae fienda sunt. This also is clear in artificial things. For as the demonstrator in demonstrating takes the definition as a principle, so also does the builder in building, and the physician in curing. Thus, because the definition of a house is such, this [what is in the definition] must come to be and exist in order that a house might come to be, and because this is the definition of health, this must come to be in order for someone to be cured. And if this and that are to be, then we must accomplish those things which must come to be.
Contingit autem quandoque in scientiis demonstrativis triplicem esse definitionem. However, in demonstrative sciences definition is threefold.
Quarum una est demonstrationis principium, ut haec: tonitruum est extinctio ignis in nube: quaedam vero demonstrationis conclusio, ut haec: tonitruum est continuus sonus in nubibus: quaedam vero complectitur utrumque, ut haec: tonitruum est continuus sonus in nubibus propter extinctionem ignis in nube; et haec comprehendit in se totam demonstrationem absque demonstrationis ordine: unde in I Poster. dicitur quod definitio est demonstratio positione differens. One of these is a principle of demonstration, for example, thunder is the extinguishing of fire in a cloud. The second is the conclusion of a demonstration, for example, thunder is a continuous sound in the clouds. The third is a combination of these two, for example, thunder is a continuous sound in the clouds caused by the extinguishing of fire in a cloud. This definition embraces within itself the whole demonstration without the order of demonstration. Hence it is said in Posterior Analytics, I:8, that definition is a demonstration differing by position.
Quia igitur in iis quae fiunt propter finem, finis se habet ut principium in demonstrativis, et ea quae sunt ad finem sicut conclusio; etiam in definitione rerum naturalium invenitur id quod est necessarium propter finem. Si enim aliquis velit definire opus serrae, quoniam est talis divisio; quae quidem non erit nisi habeat dentes, qui non erunt apti ad dividendum nisi sint ferrei: oportebit in definitione serrae ponere ferrum. Nihil enim prohibet in definitione poni quasdam partes materiae, non quidem partes individuales, ut has carnes et haec ossa; sed partes communes, ut carnes et ossa; et hoc necessarium est in definitione omnium rerum naturalium. Since, therefore, in things which come to be for the sake of an end the end is like a principle in demonstrative science, and since those things which are for the sake of the end are like the conclusion, there is also found in the definition of natural things that which is necessary because of the end. For if one wishes to define the operation of a saw (which is a division of a certain sort which will not occur unless the saw has teeth, and these teeth are not suitable for cutting unless they are of iron), it’ will be necessary to place iron in the definition of saw. For nothing prevents us from placing certain parts of matter in the definition, not individual parts, such as this flesh and these bones, but common parts, such as flesh and bones. And this is necessary in the definition of all natural things [cf. L5 #179].
Sicut igitur definitio quae colligit in se principium demonstrationis et conclusionem est tota demonstratio; ita definitio colligens finem et formam et materiam, comprehendit totum processum generationis naturalis. Therefore, the definition which comprises in itself the principle of the demonstration and the conclusion is the whole demonstration. Thus the definition which draws together the end, the form, and the matter comprises the whole process of natural generation.