2497. 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 that he introduces in Physics 8, which he assumes as the basis of his procedure here, are not demonstrations in the strict sense but only probable 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. 2498. 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 that 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. 2499. 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 that prove that motion and time are eternal are not demonstrative and necessarily conclusive, still the things that 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 2 (994a11; [301–4]), it is necessary to posit an eternal substance whose essence contains no potency and is therefore immaterial. Lectio 6 Lecture 6 Eternal motion requires an eternal mover Quamvis dubitatio. Videtur enim agens quidem omne posse, potens vero non omne agere. Quare prius esse potentiam. There is a difficulty, however; for it seems that, while everything that is acting is able to act, not everything that is able to act is acting. Thus potency is prior. At vero si hoc, nihil erit entium. Contingit enim quidem posse esse, nondum vero esse: et etiam sicut dicunt theologi, qui ex nocte generant, aut ut physici, quibus erant simul res omnes, dicunt idem impossibile. Quomodo enim movebuntur, si non fuerit actu aliqua causa? Non enim materia ipsa seipsam movebit, sed tectonica. Nec menstrua nec terra, sed semina et genitura. But if this is so, no beings will exist; for everything may be capable of being, but still not be. And if we take what the theologians say, who generate everything from night, or what the philosophers of nature say, who affirm that all things were together, they express the same impossible view. For how will things be moved, if there is no actual cause? Matter will not move itself, but technical knowledge will move it; nor will menstrual blood or earth move themselves, but semen or seed will move them. Propter quod faciunt quidam semper actum, ut Leucippus et Plato. Semper enim dicunt esse motum. Sed quare, et quem, non dicunt, nec sic, nec causam. Nihil enim ut contingit movetur, sed oportet semper aliquid existere. This is the reason why some men, such as Leucippus and Plato, posit something which is always actual, for they say that motion always exists. But they do not say why it exists, or what it is, or how this is so, or what its cause is. For nothing is moved by chance, but there must always be something existing which moves it. Quemadmodum nunc, natura quidem sic, vi vero, aut ab intellectu, aut ab alio sic. Deinde qualis prior? Differt enim valde quodcumque est. At vero nec Platonem possibile dicere, quod existimat aliquando principium esse quod ipsum seipsum movet. Posterius enim, et simul caelo, anima, ut ait. Now things are moved in one way by nature, and in another by force or by mind or by some other agent. What kind of motion, then, is prior? For this makes the greatest difference. Plato cannot explain what it is that he sometimes thinks is the source of motion, namely, what moves itself. According to him, the soul is later than motion and simultaneous with the heavens. Potentiam quidem igitur existimare priorem actu, est quidem ut bene, est autem ut non bene. Dictum est autem quomodo. Now, to think that potency is prior to act is in one sense right and in another not, and we have explained how this is so (1071b22). Quod autem actus prius, testatur Anaxagoras: intellectus enim actus. Et Empedocles amicitiam et litem. Et semper dicentes motum esse, ut Plato et Leucippus. That act is prior is affirmed by Anaxagoras (for mind is an act), and by Empedocles in his theory of love and strife (984b32), and by those who say that motion always existed, as Plato and Leucippus. Quare non fuit infinito tempore chaos, aut nox, sed eadem semper, aut periodo, aut aliter, si prior est actus potentia. Hence Chaos or Night did not exist for an infinite time, but the same things have always existed, either in a cycle or in some other way, granted that act is prior to potency. Si itaque idem semper periodo, oportet aliquid semper manere similiter agens. Si autem debeat fore generatio et corruptio aliud oportet agens esse aliter et aliter. Necesse est igitur, sic quidem secundum se agere, sic vero secundum aliud. Aut ergo secundum alterum, aut secundum primum. Therefore, if something is always moved in the same cycle, there must be something which always continues to act in the same way. But if there is to be generation and destruction, there must be something else which acts in different ways. Hence this must act in one way of itself and in another way in virtue of something else, namely, in virtue either of some third agent or of the first. Necesse est igitur secundum hoc: etenim illud ipsum causa et illi. Dignius ergo primum: etenim causa erat illud ipsius semper similiter, et ipsius aliter, alterum: eius autem quod est semper aliter, palam quod ambo. Now, it must be in virtue of the first, for this is the cause both of the second and of the third. The first is preferable, then, for it was the cause of that whose being is always to be the same, and something else was the cause of that whose being is to be different; and obviously both of these account for eternal diversity. Ergo si sic se habet motus, quid ergo alia oportet quaerere principia? Therefore, if motion always exhibits these characteristics, why is it necessary to look for other principles? Quoniam autem ita contingit, et si non sit, ex nocte erunt, et simul omnia, et ex non ente, solventur utique haec. And since this is a possible account of the matter, and if this is not so, all things will come from Night (1071b25) or all things were together (1071b25) or something comes from non-being (1069b26), these difficulties are solved. Et est aliquid semper motum motu incessabili. Haec autem quae circulo. Et hoc non ratione solum, sed opere palam, quare sempiternum erit utique primum caelum. And there is something which is always being moved with an unceasing motion, and this is circular motion. This is evident not only in theory, but in fact, and for this reason, the first heaven will be eternal. Est igitur aliquid et quod movet. Quoniam autem quod movetur, et movens et medium. Igitur est aliquid quod non motum movet sempiternum, et substantia, et actus ens. Therefore, there is also something which causes it to move. And since that which is moved and causes motion is intermediate, there must be something which causes motion and is unmoved, which is eternal and both a substance and an act. 2500. Movet quamdam dubitationem circa praedeterminata. Et est dubitatio, utrum actus sit simpliciter prior potentia, ut possit poni primum principium rerum esse tale, cuius substantia sit actus. Et circa hoc tria facit. 2500. He raises a question about a point already dealt with. The question is whether act is prior absolutely to potency such that the first principle of things can be held to be one whose substance is act. In regard to this, he does three things. Primo ponit rationem ad ostendendum falsum, scilicet quod potentia sit prior actu. First (1071b22; [2500]), he gives an argument to show what is false, namely, that potency is prior absolutely to act. Secundo ponit rationem in contrarium, ibi, at vero si hoc, nihil erit. Second (1071b25; [2501]), he argues on the other side of the question, at but if this is so. Tertio solvit dubitationem, ibi, potentiam quidem igitur. Third (1072a3; [2506]), he answers the question, at now, to think. Dicit ergo primo, quod dictum est, quod substantia sempiterna est actus, quamvis de hoc sit dubitatio. Videtur enim potentia simpliciter esse prior actu: nam prius est a quo non convertitur consequentia essendi. Hoc autem modo videtur potentia se habere ad actum: quia omne agens videtur posse agere, sed non omne quod potest agere agit; quare videtur quod potentia sit prior actu. He accordingly first says (1071b22) that it has been pointed out that an eternal substance is an act, although there is a difficulty regarding this. For potency seems to be prior to act, since one thing is prior to another when the sequence of their being cannot be reversed (1019a2; [950]). Now potency seems to be related to act in this way, because everything that is acting seems to be able to act, but not everything that is able to act is acting. Thus it seems that potency is prior to act. 2501. Deinde cum dicit at vero si ponit rationem in contrarium. Et circa hoc duo facit. 2501. But if this is so (1071b25). Then he argues on the opposite side of the question, and in regard to this, he does two things. Primo ponit rationem ducentem ad impossibile: dicens, quod si potentia sit simpliciter prior actu, sequitur quod aliquando nihil sit: contingens est enim id quod potest fieri, sed nondum fit. Et ita, si prima entia sunt in potentia, sequitur quod non sunt actu: et sic nihil aliorum erit. First, he gives an argument reducing the counter-position to absurdity. He says that, if potency is prior absolutely to act, it follows that, at some time, nothing may exist; for the contingent is what can come to be but has not yet done so. Hence, if the primary beings are potential, it follows that they do not exist actually; and so no other being will exist. 2502. Et hoc quidem contingit dupliciter. 2502. This can be taken in two ways. Uno modo secundum opinionem quorumdam antiquorum, qui vocabantur poetae theologi, sicut fuit Orpheus, et quidam alii, qui ponebant mundum esse generatum ex nocte, idest simplici privatione praeexistente. First, according to the opinion of certain of the ancients who were called the theological poets, such as Orpheus and certain others, who claimed that the world is generated from night, that is, from a simple preexistent privation. Alio modo secundum posteriores naturales, sicut physici naturales, et eos sequentes, qui cum viderent quod secundum naturam nihil fit ex nihilo, posuerunt omnia esse simul in quadam confusione, quam vocabant chaos, sicut posuit Anaxagoras: et sic ponebant omnia esse in potentia, non autem in actu. Second, according to the later physicists—namely the philosophers of nature and their followers—who, when they saw that nothing comes from nothing in the natural world, claimed that all things were together in a kind of mixture, which they called Chaos (as did Anaxagoras, for example), and thus held that all things exist potentially and not actually. 2503. Sed, sive hoc modo, sive illo dicatur, sequitur idem impossibile, si potentia simpliciter sit prior actu. Illa enim quae sunt in potentia tantum, sive sint omnino sub privatione, sive sint in quadam confusione, non poterunt moveri, ut reducantur in actum, nisi sit aliqua causa movens in actu existens; quia materia in artificialibus non movet seipsam, sed ipsam movet agens, scilicet tectonica, idest ars. Nec menstrua, quae sunt materia in generatione animalis, movent seipsa, sed movet ea genitura, idest semen animalis. Nec terra, quae est materia in generatione plantarum, movet seipsam, sed movent eam spermata, idest semina plantarum. 2503. But, whether this position is stated in the former or in the latter way, the same impossible conclusion follows, provided that potency is prior absolutely to act. For those things that are in potency only, or which come entirely under privation, or belong to some confused mass, cannot be moved so as to be brought to act unless there is some moving cause that is existing actually. For in things made by art, the matter does not move itself, but an agent moves it, namely, technical knowledge, or art. Neither does the menstrual blood, which is the matter from which an animal is generated, move itself, but semen, that is, the sperm of the animal, moves it. Nor does earth, which is the material from which plants are generated, move itself, but the seed, namely, the seeds of plants, move it. 2504. Secundo ibi, propter quod ostendit quomodo huic rationi quidam physici consenserunt. Dicit ergo, quod propter hanc rationem quidam philosophi posuerunt semper actum existentem, scilicet Leucippus socius Democriti, et Plato. Dixerunt enim motum semper fuisse etiam ante mundum. Secundum quidem Leucippum in atomis per se mobilibus, ex quibus ponebat mundum constitui. Secundum Platonem vero in elementis, quae dicebat ante constitutionem mundi mota fuisse motibus inordinatis, sed postea a Deo fuisse ea reducta ad ordinem. 2504. This is the reason (1071b31). Second, he shows how some of the philosophers of nature agreed with this argument. He says that this is the reason why some philosophers—Leucippus, the companion of Democritus, and Plato—claimed that something actual always exists. For they said that motion had always existed even before the world. Leucippus attributed motion to the atoms, which are mobile of themselves, from which he supposed the world to be composed; and Plato attributed it to the elements, which he said were moved by disorderly motions before the formation of the world, and afterwards were brought into order by God. 2505. Sic igitur quantum ad hoc videntur bene dixisse, quod posuerunt semper fuisse motum. Sed in hoc defecerunt, quia non dixerunt quis motus semper fuerit, nec causam motus assignaverunt, nec simpliciter narrando, nec suae positionis causam assignando, cum tamen nihil moveatur ut contingit, idest sine aliqua causa certa. Sed semper oportet aliquid existere, quod est causa motus. Sicut nunc videmus, quod quaedam moventur hoc modo a natura, aut a violentia, aut ab intellectu, aut aliqua alia causa. Deinde debuerunt etiam assignare, qualis sit prima causa motus, utrum natura, sive violentia, sive intellectus; multum enim differt quodcumque horum ponatur causa motus. Sed nec Plato potest excusari, propter hoc, quod posuit principium motus esse aliquid movens seipsum, quod dicebat esse animam: sed anima secundum ipsum non fuit ante constitutionem mundi, sed fuit post illam inordinationem motus. Fuit enim facta simul cum caelo, quod ponebat animatum. Et sic anima non poterit esse principium illius motus inordinati. 2505. Now, they seem to be right in claiming that motion has always existed. But they were wrong in failing to point out which kind of motion has always existed; nor did they give the cause of motion, either by stating this in an absolute sense or by giving the reason for their own position. Yet nothing is moved by chance, that is, without some fixed cause, but there must always be something existing that is the cause of motion. For example, we now see that some things are moved in this way by nature or by force or by mind or by some other agent. Hence they should also have stated what the first cause of motion is, whether it was nature or force or mind. For it makes a great deal of difference which of these is held to be the cause of motion. But Plato cannot be excused on the ground that he held the principle of motion to be something that moves itself, which he asserted to be a soul, since the soul did not exist of itself before the formation of the world, but only existed after the disorderly state of motion. For, according to him, the soul was created at the same time as the heavens, which he claimed to be animated; thus it could not be the principle of that disorderly motion. 2506. Deinde cum dicit potentiam quidem solvit propositam quaestionem. Et circa hoc duo facit. 2506. Now, to think (1072a3). Then he answers the question which was raised, and concerning this, he does two things. Primo remittit ad hoc quod determinatum est in nono de ordine potentiae ad actum; dicens, quod opinari potentiam esse priorem actu, quodam modo bene dicitur, et quodam modo non. Et quomodo hoc sit, dictum est in nono. Ibi enim dictum est, quod actus simpliciter est prior potentia; sed in uno eodem quod movetur de potentia in actum, potentia praecedit actum tempore, quamvis actus sit prior natura et perfectione. First, he returns to the points established in book 9 regarding the relationship of potency to act. He says that the opinion that potency is prior to act is in one sense right and in another not. The sense in which it is right has been explained in book 9 (1049b4–1049b17; [1844–49]), for it was stated there that act is prior absolutely to potency. But in one and the same subject that is being moved from potency to act, potency is prior to act in time, although act is prior both in nature and in perfection. 2507. Secundo ibi, quod autem confirmat solutionem per positiones quorumdam philosophorum; dicens, quod hoc quod actus sit simpliciter prior, testatur Anaxagoras, quia posuit primum principium movens esse intellectum. Intellectus enim actus quidam est. Et etiam Empedocles, qui posuit causas moventes litem et amicitiam. Et Leucippus et Plato, qui posuerunt semper motum fuisse. 2507. That act is prior (1072a4). Second, he strengthens his answer by giving the opinions of some of the philosophers. He says that the absolute priority of act is asserted by Anaxagoras, because he claimed that the first principle of motion is an intellect, for intellect is a kind of act. The same thing is also asserted by Empedocles, who claimed that love and strife are the causes of motion, and also by Leucippus and Plato, who claimed that motion has always existed. 2508. Deinde cum dicit quare non ex determinatione quaestionis praemissae manifestat quod prius ostensum est. Et circa hoc tria facit. 2508. Hence Chaos or Night (1072a7). Then he uses the answer to the question given above to clarify a point previously established, and in regard to this, he does three things. Primo concludit ex praemissis perpetuitatem generationis. First (1072a7; [2508]), in the light of the things established above, he concludes that generation must be eternal.