Authors/Thomas Aquinas/metaphysics/liber12/lect5

Lecture 5

Latin	English
lib. 12 l. 5 n. 1 Postquam philosophus ostendit quae sunt principia substantiae sensibilis, hic incipit determinare de substantiis immobilibus a materia separatis. Et dividitur in partes duas. In prima determinat de huiusmodi substantiis secundum propriam opinionem. In secunda secundum opinionem aliorum, sequenti libro, ibi, de sensibili quidem igitur substantia. Prima in duas. In prima ostendit esse aliquam substantiam sempiternam, immobilem, a materia separatam. In secunda inquirit conditionem huius substantiae, ibi, movet autem. Circa primum tria facit. Primo ostendit esse aliquam substantiam sempiternam. In secunda pertractat quamdam quaestionem ex dictis occasionatam, ibi, quamvis dubitatio. Tertio ex solutione quaestionis motae procedit ad manifestationem veritatis prius inventae, ibi, quare non fuit infinito tempore. Circa primum duo facit. Primo ostendit, quod necesse est ponere aliquam substantiam sempiternam. Secundo ostendit qualem oportet esse illam substantiam, ibi, sed si fuerit motivum. Dicit ergo primo, quod supra dictum est, quod tres sunt substantiae: quarum duae sunt substantiae naturales, quia sunt cum motu: una sempiterna, ut caelum; alia corruptibilis, ut plantae et animalia; et praeter has, est tertia, quae est immobilis, quae non est naturalis: de hac dicendum est nunc. Ad cuius considerationem oportet prius ostendere, quod necesse est esse aliquam substantiam, sempiternam, immobilem. Quod sic probat.	2488. After having shown what the principles of sensible substances are, here the Philosopher begins to establish the truth about the immovable substances, which are separate from matter. This topic is divided into two parts. First (1055)C 2488), he treats substances of this sort by giving his own opinion. Second, he treats them by giving the opinions of other thinkers. He does this in the following book (“Concerning the substance of sensible things”). The first part is divided into two members. First, he proves that there is a substance which is eternal, immovable and separate from matter. Second (1067:C 2519) he investigates the attributes of this substance (“Now the first mover”). In regard to the first he does three things. First, he proves that an eternal substance must exist. Second (1059:C 2500), he deals with a question arising from the foregoing discussion (“There is a difficulty, however”); and third (1064:C 2508), from the answer given to the question which was raised he proceeds to clarify a truth previously ,established (“Hence, Chaos or Night”). In regard to the first he does two things. First, he shows that it is necessary to posit an eternal substance. Second (1056:C 2492), he shows what kind of substance it must be (“But even if there is”). He accordingly says, first (1055), that it has been pointed out above (1028:C 2424) that there are three classes of substances. Two of these are natural substances, because they undergo motion—one being eternal, as the heavens, and the other perishable, as plants and animals. And besides these there is a third class, which is immovable and not natural; and of this kind of substance it is now necessary to speak. With a view to investigating this kind of substance it is first necessary to prove that an eternal immovable substance must exist. He proceeds as follows.
lib. 12 l. 5 n. 2 Substantiae sunt primae inter entia, ut supra ostensum est. Destructis autem primis nihil remanet aliorum. Si igitur nulla substantia est sempiterna, sed omnes sunt corruptibiles, sequetur quod nihil sit sempiternum, sed omnia sint corruptibilia, idest non semper existentia. Sed hoc est impossibile, ergo necesse est esse aliquam substantiam sempiternam.	2489. Substances are the primary kind of beings, as has been shown above (1024:C 2417-23), and when primary things are destroyed none of the others remain. Therefore, if no substance is eternal but all are perishable, it follows that nothing is eternal but that “all things are perishable,” i.e., they do not always exist. But this is impossible. Hence there must be an eternal substance.
lib. 12 l. 5 n. 3 Quod autem impossibile sit nihil esse sempiternum, probat ex hoc, quod impossibile est motum fieri aut corrumpi, idest de novo incepisse, aut quandoque totaliter desiturum esse. Ostensum est enim in octavo physicorum, quod motus est sempiternus simpliciter. Et videtur impossibile quod tempus non sit sempiternum. Quia, si tempus aliquando incepit, aut aliquando desinet, sequetur quod prius fuerit non esse temporis quam tempus; et iterum, quod posterius erit non esse temporis quam tempus. Sed hoc non potest esse, ut videtur; quia non est possibile esse prius et posterius nisi sit tempus, cum nihil aliud sit tempus, nisi numerus prioris et posterioris in motu: et sic sequeretur, quod tempus fuerit antequam inciperet esse, et quod sit postquam esse desierit. Videtur igitur necesse esse quod tempus sit sempiternum.	2490. That it is impossible for nothing to be eternal he proves from the fact that motion cannot have come to be or “perish,” i.e., it cannot have come to be anew or at some time totally cease to be. For it has been shown in Book VIII of the Physics that motion is eternal without qualification. It also seems impossible that time should not be eternal; for if time began to be at some time or will cease to be at some time it would follow that prior to time there was the non-being of time, and also that there will be time after the non-being of time. But this seems to be impossible, because there could be no before or after if time did not exist, since time is nothing else than the measure of before and after in motion. Thus it would follow that time existed before it began to be, and that it will exist iifter it ceases to be. Hence it seems that time must be eternal.
lib. 12 l. 5 n. 4 Et si tempus est continuum et sempiternum, necesse est quod motus sit continuus et sempiternus: quia motus et tempus, aut sunt idem, ut quidam posuerunt, aut tempus est aliqua passio motus, ut rei veritas habet. Est enim tempus numerus motus, ut patet in quarto physicorum. Sed tamen non est accipiendum de omni motu, quod possit esse sempiternus et continuus. Non enim hoc potest esse verum nisi de motu locali. Et inter motus locales, solum de motu circulari, ut probatur in octavo physicorum.	2491. And if time is continuous and eternal, motion must be continuous and eternal, because motion and time are either the same thing, as some claimed, or time is a property of motion, as is really the case. For time is the measure of motion, as is evident in Book IV of the Physics. However, it must not be thought that every motion can be eternal and continuous, since this can be true only of local motion; and among local motions this is true only of circular motion, as is proved in Book VIII of the Physics.
lib. 12 l. 5 n. 5 Deinde cum dicit at vero si ostendit cuiusmodi substantiam necesse est esse sempiternam; et circa hoc tria facit. Primo, quod ad sempiternitatem motus sustinendam, necesse est ponere substantiam sempiternam semper moventem vel agentem; dicens, quod cum necesse sit, si motus est sempiternus, quod sit substantia motiva et effectiva sempiterna, ulterius oportet quod sit movens et agens in actu semper; quia si esset motiva aut effectiva, idest potens movere et efficere motum, et non agens in actu, sequeretur quod non esset motus in actu. Non enim est necessarium, si habeat potentiam movendi, quod moveat in actu: contingit enim id quod habet potentiam agendi non agere; et ita motus non erit sempiternus. Ad hoc igitur, quod motus sit sempiternus, necesse est ponere aliquam substantiam sempiternam moventem et agentem in actu.	2492. But even if (1056). Then he shows what kind of substance this eternal substance must be, and in regard to this he does three things. First, he shows that in order to account for the eternity of motion it is necessary to posit an eternal sub~ stance which is always moving or acting. He says that, since it is necessary, on the assumption that motion is eternal, that there be an eternal substance which is capable of imparting or producing motion, it is also necessary that this be a mover or agent which is always acting, because if it were “capable of imparting or producing motion,” i.e., if it had the power to produce or cause motion, and was not actually doing so, it would follow that there would be no actual motion. For that which has the power of causing motion may possibly not be causing it, since that which has the power of acting may possibly not act; and thus motion would not be eternal. Assuming, then, that motion is eternal, it is necessary to posit an eternal substance which is actually moving or acting.
lib. 12 l. 5 n. 6 Ex quo consequenter concludit, quod nihil prodest opinio Platonis ponentis substantias sempiternas, quae est insufficiens ad sustinendum sempiternitatem motus. Non enim ad hoc sustinendum prodest, si fingamus aliquas substantias separatas sempiternas, nisi in eis sit aliquod principium habens potentiam ad transmutandum, quod non videtur convenire speciebus. Species enim nihil aliud ponebant quam universalia separata: universalia autem, inquantum huiusmodi, non movent. Nam omne principium activum vel motivum est aliquod singulare, ut supra dictum est. Sic igitur nec species sunt sufficientes ad sempiternitatem motus servandam, nec alia substantia separata praeter species, sicut quidam posuerunt mathematica separata: quia nec etiam mathematica, inquantum huiusmodi, sunt principia motus. Et si non sit aliqua substantia sempiterna agens, non est motus sempiternus; quia motus principium est aliqua substantia sempiterna movens et agens.	2493. Next, he concludes from this that nothing is to be gained by accepting the opinion of Plato, who posited eternal substances, since this is not sufficient to account for the eternity of motion. For the assumption that there are certain separate and eternal substances is not sufficient to account for this unless there is some principle among them which can ~ause change; but this does not seem to fit the separate Forms. For Plato claimed that the separate Forms are nothing else than universals existing apart from matter. But universals as such do not cause motion; for every active or motive principle is a singular thing, as has been pointed out above (1053:C 2482). Neither the separate Forms, then, nor any other separate substances besides the Forms, such as the separate mathematical entities posited by some, are sufficient to account for the eternity of motion, because even the objects of mathematics as such are not principles of motion. And if there is no eternal active substance, there will be no eternal motion, because the principle of motion is an eternal substance which is a mover or agent.
lib. 12 l. 5 n. 7 Secundo ibi, adhuc neque ostendit ulterius, quod oportet ad sempiternitatem motus, quod non solum sit aliqua substantia sempiterna movens et agens, sed etiam quod eius substantia sit actus. Dicit ergo, quod neque est sufficiens ad sempiternitatem motus, si substantia sempiterna agat, sed tamen secundum suam substantiam sit in potentia; sicut si ponamus prima principia esse ignem aut aquam secundum positionem antiquorum naturalium: non enim poterit esse motus sempiternus. Si enim sit tale movens, in cuius substantia admiscetur potentia, contingit id non esse. Quia quod est in potentia contingit non esse. Et per consequens continget quod motus non sit, et sic motus non erit ex necessitate, et sempiternus. Relinquitur ergo, quod oportet esse aliquod primum principium motus tale cuius substantia non sit in potentia, sed sit actus tantum.	2494. And even if (1057). Second, be shows that, in order for motion to be eternal it is necessary not only that an eternal substance exist, which is a mover or agent, but also that its essence be an actuality. Hence he says that the eternity of motion is not adequately accounted for even if it is supposed that an eternal substance does act yet is potential in essence. For example, it would not be sufficient to hold that the first principles are fire or water, as the ancient natural philosophers did, because then motion could not be eternal. For if a mover is such that its essence contains potentiality, it can possibly not be, because whatever is in potentiality may possibly not be. Hence it would be possible for motion not to be, and so it would not be necessary and eternal. Therefore it follows that there must be a first principle of motion of the sort whose essence is not in potentiality but is only an actuality.
lib. 12 l. 5 n. 8 Tertio ibi, amplius igitur concludit ulterius, quod oportet huiusmodi substantiam esse immaterialem. Dicit ergo, quod amplius ex praedictis sequitur, quod huiusmodi substantias, quae sunt principia motus sempiterni, oportet esse sine materia. Nam materia est in potentia. Oportet igitur eas esse sempiternas, si aliquid aliud est sempiternum, utpote motus et tempus. Et sic sequitur quod sint in actu.	2495. Further, such substances (1058). Third, he further concludes that this kind of substance must be immaterial. He says that it also follows from the foregoing (1055-57:C 2488-94) that substances of this kind, which are the principles of eternal motion, must be free from matter; for matter is in potentiality. Therefore they must be eternal if something else is eternal, as motion and time. Thus it follows that they are actualities.
lib. 12 l. 5 n. 9 Hoc autem ultimo concludit propter dubitationem quam consequenter inducet. Ex hoc igitur processu manifestum est quod Aristoteles hic firmiter opinatus est et credidit necessarium fore, quod motus sit sempiternus et similiter tempus. Aliter enim non fundasset super hoc intentionem suam de inquisitione substantiarum immaterialium.	2496. He concludes in this way last because of the question which be will next raise. From this reasoning, then, it is evident that here Aristotle firmly thought and believed that motion must be eternal and also time; otherwise he would not have based his plan of investigating immaterial substances on this conviction.
lib. 12 l. 5 n. 10 Sed tamen sciendum quod rationes ab eo inductae in octavo physicorum, ex quarum suppositione hic procedit, non sunt demonstrationes simpliciter, sed probabiles rationes. Nisi forte sint demonstrationes contra positiones antiquorum naturalium de inceptione motus, quas destruere intendit.	2497. Yet it should be noted that the arguments which he introduces in Book VIII of the Physics, which he assumes as the basis of his procedure here, are not demonstrations in the strict sense but only dialectical arguments; unless perhaps they are arguments against the positions of the ancient natural philosophers regarding the beginning of motion, inasmuch as he aims to destroy these positions.
lib. 12 l. 5 n. 11 Et praetermissis aliis rationibus quas hic non tangit, manifestum est quod ratio quam hic posuit ad probandum sempiternitatem temporis, non est demonstrativa. Non enim, si ponimus tempus quandoque incepisse, oportet ponere prius nisi quid imaginatum. Sicut cum dicimus quod extra caelum non est corpus, quod dicimus extra, non est nisi quid imaginatum. Sicut igitur extra caelum non oportet ponere locum, quamvis extra videatur locum significare, ita non est necessarium quod tempus sit prius quam incipiat vel postquam desinet, licet prius et posterius videantur tempus significare.	2498. And aside from the other arguments which he does not touch upon here, it is evident that the argument which he does give here to prove that time is eternal is not demonstrative. For if we suppose that at some moment time began to be, it is not necessary to assume a prior moment except in imaginary time; just as when we say that there is no body outside of the heavens what we mean by “outside” is merely an imaginary something. Hence, just as it is not necessary to posit some place outside of the heavens, even though “outside” seems to signify place, so too neither is it necessary that there be a time before time began to be or a time after time will cease to be, even though before and after signify time.
lib. 12 l. 5 n. 12 Sed quamvis rationes probantes sempiternitatem motus et temporis non sint demonstrativae et ex necessitate concludentes, tamen ea quae hic probantur de sempiternitate et immaterialitate primae substantiae, ex necessitate sequuntur. Quia si non fuerit mundus aeternus, necesse est quod fuerit productus in esse ab aliquo praeexistente. Et si hoc non sit aeternum, oportet iterum quod sit productum ab aliquo. Et cum hoc non possit procedere in infinitum, ut supra in secundo probatum est, necesse est ponere aliquam substantiam sempiternam, in cuius substantia non sit potentia, et per consequens immaterialem.	2499. But even if the arguments which prove that motion and time are eternal are not demonstrative and necessarily conclusive, still the things which are proved about the eternity and immateriality of the first substance necessarily follow; for, even if the world were not eternal, it would still have to be brought into being by something that has prior existence. And if this cause were not eternal, it too would have to be produced by something else. But since there cannot be an infinite series, as has been proved in Book II (153:C 301-4), it is necessary to posit an eternal substance whose essence contains no potentiality and is therefore immaterial.