967. Deinde cum dicit: esse quidem igitur etc., respondet tacitae quaestioni. In praecedentibus enim libris Aristoteles locutus fuerat de motu in communi, non applicando ad res: nunc autem inquirens an motus semper fuerit, applicat communem considerationem motus ad esse quod habet in rebus. Posset ergo aliquis dicere, quod in hac consideratione prius erat quaerendum de motu, an habeat esse in rebus, quam quaeratur an sit sempiternus: et praecipue, cum quidam negaverint esse motum. 967. Then, at now, the existence of (250b15), he answers a tacit question. For in the preceding books, Aristotle had discussed motion in common, without applying it to things; but now, inquiring whether motion has always existed, he applies his general doctrine about motion to the existence it has in things. Therefore, someone could say that, in this consideration, the first question should have been about whether motion has existence in things, rather than whether it is eternal, especially since there are some who have denied that motion exists. Ad hoc respondet, dicens quod omnes qui locuti sunt de natura rerum, affirmant quod motus sit. Et hoc patet per hoc, quod dicunt mundum esse factum; et quod omnes considerant de generatione et corruptione rerum, quae non potest esse sine motu. Est igitur communis suppositio in scientia naturali, quod motus habeat esse in rebus. Unde de hoc non est quaerendum in scientia naturali: sicut nec in aliqua scientia movetur quaestio de suppositionibus illius scientiae. To this, he responds that all who have spoken about the nature of things admit that motion exists. This is evident from their statements that the world was made, and from their consideration of the generation and ceasing to be of things, which cannot occur without motion. It is therefore a common supposition in natural science that motion has existence in things. Hence, there is no need to raise this question in natural science any more than in other sciences are raised questions about the suppositions of the science. 968. Deinde cum dicit: sed quanti quidem etc., ponit opiniones ad utramque partem quaestionis motae. 968. Then, at but those who say (250b18), he presents opinions for both sides of the question he proposed. Et primo ponit opiniones dicentium motum semper esse; First, he gives the opinions that declare that motion is eternal; secundo opiniones ponentium motum non semper esse, ibi: quicumque autem etc. second, those who declare that motion is not eternal, at but those who hold (250b21; [969]). Ad evidentiam ergo primae partis sciendum est, quod Democritus posuit prima rerum principia corpora indivisibilia per se et semper mobilia, ex quorum aggregatione dicebat mundum casualiter factum: et non solum istum in quo nos sumus, sed infinitos alios, secundum quod accidit in diversis partibus infiniti vacui, praedicta corpora congregata mundos fecisse. Nec tamen hos mundos ponebat in perpetuum duraturos; sed quosdam eorum fieri per aggregationem atomorum, quosdam vero corrumpi per eorum segregationem. Quotcumque igitur philosophi hoc ponunt cum Democrito, dicunt semper esse motum; quia semper dicunt esse generationes et corruptiones aliquorum mundorum, quas necessarium est esse cum motu. In explanation of the first part (250b18), therefore, it should be known that Democritus supposed that the first principles of things are bodies that are per se indivisible and always mobile and that the world came to be by the chance aggregation of these bodies—not only the world in which we exist, but an infinitude of other worlds, since these bodies congregated to form worlds in diverse parts of infinite void. Still, he did not posit these worlds as fated to endure forever; rather, some came into existence as a result of atoms combining, and others passed out of existence as a result of the same atoms scattering. Therefore, all the philosophers who agree with Democritus assert the eternity of motion, because they say that the generation and ceasing to be of certain worlds is always going on—and that necessarily involves motion. 969. Deinde cum dicit: quicumque autem etc., ponit opiniones ad partem contrariam. Et dicit quod quicumque ponunt unum solum mundum, et non esse eum sempiternum, etiam de motu ponunt quod consequitur secundum rationem, ut scilicet non semper sit. 969. Then, at but those who hold (250b21), he gives the opinions of the other side. And he says that whoever declares that there is just one world that is not eternal also declares what reasonably follows with respect to motion, namely, that it is not eternal. Si ergo ponatur quod sit aliquod tempus in quo nihil movebatur, oportet quod hoc accidat duobus modis, sicut etiam duobus modis potest poni hic mundus non semper fuisse: Therefore, if there be supposed a time in which nothing was in motion, this could happen in two ways, just as it is in two ways that this world could be supposed not always to have been: uno modo quod mundus iste sic inceperit quod nunquam antea fuerit, sicut posuit Anaxagoras; in one way, that this world began in such a way that previously it never existed at all, as Anaxagoras held; alio modo quod mundus sic inceperit quod aliquo tempore non fuerit, sed ante illud tempus iterum fuerit, ut posuit Empedocles. in another way, that the world so began to be that it did not exist for some time previously, but that it again had existed before that time, as Empedocles held. Et similiter circa motum Anaxagoras dixit quod quondam omnia simul erant unum cum alio commixtum, et nihil erat ab alio segregatum: in qua quidem rerum mixtura necesse fuit ponere quod omnia quiescerent: motus enim non est absque disgregatione; omne enim quod movetur, ab aliquo recedit, ut in aliud tendat. In like manner, with respect to motion, Anaxagoras said that, at one time, all things were a mixture of one thing with another and nothing was separated from anything else—in which mixture it was necessary to posit that all things were at rest, for motion does not occur without separation, since whatever is in motion separates from one terminus in order to tend to another. Hanc ergo rerum mixturam et quietem posuit praeextitisse in tempore infinito, ita quod nunquam antea fuerat aliquis motus; et quod intellectus, qui solus non erat permixtus, incepit de novo facere motum, et disgregare res ab invicem. Therefore, Anaxagoras posited the preexistence of this mixture and rest in infinite time, in such a way that at no time before had there been any motion at all, and that it was Mind, which alone was unmixed, that caused motion in the first instance and began to separate things one from another. Empedocles vero dixit quod in aliqua parte temporis est aliquid moveri, et iterum in alia parte temporis est omnia quiescere. Ponebat enim Empedocles quod amicitia et discordia sunt prima rerum moventia: amicitiae autem proprium est quod ex multis faciat unum, discordiae vero quod ex uno faciat multa. Quia vero ad esse corporis mixti requiritur quod elementa sint in unum commixta, ad esse vero mundi requiritur quod elementa sint in locis suis per ordinem distributa: ponebat quod amicitia est causa generationis corporum mixtorum, discordia vero causa corruptionis; sed e contrario in toto mundo amicitia causa corruptionis, et discordia generationis. Empedocles, on the other hand, said that in one period of time some things are in motion, and again in another period all things are at rest. For he posited love and strife as the first movers of things: love’s property was to make a unity of all things, and strife’s to make many things from the one. But the existence of a mixed body requires a mingling of the elements so as to form one thing, while the existence of a world required that the elements be dispersed in orderly fashion, each to its respective place. Therefore, love is the cause of the coming to be of mixed bodies, and strife the cause of their ceasing to be. But on the contrary, love was the cause of the whole world’s ceasing to be and strife the cause of its coming to be. Sic ergo ponebat moveri totum mundum, cum vel amicitia ex multis facit unum, vel discordia multa facit ex uno: sed quietem ponebat esse in mediis temporibus, non quidem ita quod nihil moveretur, sed quantum ad generalem mundi mutationem. Accordingly, he posited that the whole world is being moved when either love makes one from the many or when strife makes many of the one; but during the intermediate times, he supposed there was rest—not in the sense that there was no motion at all, but none with respect to the general change of the world. Et quia posuit sententiam Empedoclis, ponit etiam eius verba, quae difficultatem habent, quia metrice scripsit. Because Aristotle had mentioned the opinion of Empedocles, he also gave the very words, which are difficult to interpret because they are in meter. Sic ergo suam sententiam expressit Empedocles his verbis, quae sic construenda sunt: didicit nasci, idest sic consuetum est aliquid generari, inquantum ex pluribus fit unum; et iterum, idest alio modo, ex uno geminato, idest composito, perficiuntur plurima, idest fiunt multa per disgregationem: quaedam enim sunt quae generantur per compositionem, quaedam vero per disgregationem. Thus, therefore, did Empedocles express his opinion in this arrangement of words: since one hath learned to spring, that is, it is customary for something to be generated, from manifold; and again, that is, in another way, one commingled, that is, composed of a mixture, makes manifold arise, that is, the many come to be through separation—for some things are generated by combining with others, and others by separating. Et sicut hoc videmus in particularibus generationibus, sic fiunt res, idest sic est intelligendum in universali rerum generatione quantum ad totum mundum. Et nullo modo est ipsius saeculum unum, idest non est unus status durationis rerum; sed quandoque generatur mundus, quandoque corrumpitur, quandoque medio modo se habet: saeculum enim dicitur mensura durationis alicuius rei. And according to what we observe in regard to particular instances of coming to be, so thus do things come to be, that is, the same must be understood in the universal coming to be of things with respect to the whole world. Nor is their era one, that is, there is not just one period of duration of things, but at one time a world is generated, at another it is destroyed, and in between there is rest; for “era” is taken to mean the measure of the duration of a thing. Distinctionem autem horum saeculorum exprimit subdens, sic autem permutantur; quasi dicat: unum saeculum est in quo res permutantur per congregationem vel segregationem. Et ne aliquis opinaretur quod ad generationem mundi non requiritur saeculum, idest tempus aliquod, sed mundus fit in instanti, ad hoc excludendum subiungit: neque simul perficiuntur, sed per multam moram temporis. He expresses the distinction of these eras when he adds, thus they change, that is, as though stating that the time in which things pass through the cycle of combining or separating is called one era. And, lest anyone suppose that the generation of a world does not require an era, that is, a period of time, but that the universe comes to be in an instant, Empedocles adds, nor are they made perfect all at once, but after a long interval of time. Deinde de alio saeculo subdens dicit: sic autem semper sunt immobiles; quia scilicet in medio tempore generationis et corruptionis posuit res quiescere. Et ne aliquis crederet quod semper antea fuerit permutatio, et postea semper futura sit quies, ad hoc excludendum dicit, secundum circulum; quasi dicat: circulariter hoc contingit, quod permutantur res et postea quiescunt, et iterum permutantur, et sic in infinitum. Then, speaking of the other era, he adds, thus are they always immobile; that is, in the time between the generation and corruption cycle, he supposed that things are at rest. And, lest anyone believe that there was always change before, and that later there will be continual rest, he excludes this by saying alternate, as though saying that this happens in cycles, namely, that things change and then rest and then change again, and so on to infinity. Deinde subduntur verba Aristotelis exponentis praedicta verba Empedoclis, maxime quantum ad hoc quod dixit, sic autem permutantur. Dicit ergo quod opinandum est in hoc quod dixit, sic permutantur, intellexisse ab hinc inde, idest a quodam principio usque nunc; non quod semper fuerit motus, vel quod postquam incepit, sit interruptus. Then the words of Aristotle are added to explain the foregoing words of Empedocles, especially the expression thus they change. He says therefore that following the words, thus they change, must be understood the addition, from then hence, that is, from a definite beginning up to the present—not in the sense that motion always was or that, after it began, it had been interrupted. 970. Deinde cum dicit: considerandum igitur etc., ostendit utilitatem huius considerationis. Et dicit quod considerandum est quomodo se habeat veritas circa hanc quaestionem: quia scire veritatem huius quaestionis est praeopere, idest pernecessarium, non solum ad considerationem scientiae naturalis, sed etiam ad scientiam de primo principio: quia et hic in octavo et in Metaphys., ad probandum primum principium, utitur aeternitate motus. 970. Then, at we must consider, then (251a5), he shows the usefulness of considering the question he has proposed. And he says that we must consider just what is the truth about this question, for to know the truth about it is of importance not only for natural science, but the science of the first principle as well, since, both here in book 8 and in the Metaphysics, he uses the eternity of motion to prove the first principle. Haec enim via probandi primum principium esse, est efficacissima, cui resisti non potest. Si enim mundo et motu existente sempiterno, necesse est ponere unum primum principium; multo magis sempiternitate eorum sublata; quia manifestum est quod omne novum indiget aliquo principio innovante. This method of proving the existence of a first principle is most efficacious and irresistible. For if, on the supposition that both motion and the world existed forever, it is necessary to posit one first principle, then, if the eternity of it should be rejected, it is all the more necessary, for it is clear that every new thing requires a principle bringing it into being. Hoc ergo solo modo poterat videri quod non est necessarium ponere primum principium, si res sunt ab aeterno. Unde si etiam hoc posito sequitur primum principium esse, ostenditur omnino necessarium primum principium esse. Thus the only reason that it could seem that no first principle would be necessary would be if things were from eternity. But, if the existence of a first principle follows even on that supposition—that is, that the world existed from eternity—it is clear that the existence of a first principle is absolutely necessary. Lectio 2 Lecture 2 Rationes ad ostendendum motum esse sempiternum Arguments for the eternity of motion Incipiemus autem primum ex definitis a nobis in Physicis prius. Dicimus autem motum esse actum mobilis secundum quod est mobile: necesse ergo existere res possibiles moveri secundum unumquemque motum. Let us take our start from what we have already laid down in our course on physics. Motion, we say, is the act of the movable insofar as it is movable. Each kind of motion, therefore, necessarily involves the presence of the things that are capable of that motion. Et sine motus definitione, omnis utique confitebitur necessarium esse moveri possibile moveri secundum unumquemque motum, ut alterari alterabile, ferri autem secundum locum mutabile. In fact, even apart from the definition of motion, everyone would admit that, in each kind of motion, it is that which is capable of that motion that is in motion, and thus it is that which is capable of alteration that is altered, and that which is capable of local change that is in locomotion. Quare prius oportet esse combustibile quam comburatur, et combustivum quam comburere. And, likewise, there must be something combustible before there can be a being burned, and something combustive before there can be a burning. Ergo et haec necessarium est aut facta aliquando esse, cum non essent; aut perpetua esse. Si igitur factum est mobilium unumquodque, necessarium est prius accepta aliam mutationem factam esse et motum, secundum quem factum est possibile motum esse aut moveri. Moreover, these things also must either have a beginning before which they had no being, or they must be eternal. Now, if there was a becoming of every movable thing, it follows that, before the motion in question, another change or motion must have taken place in which that which was capable of being moved or of causing motion had its becoming. Si autem quae sunt, praeerant semper, motu non existente, irrationabile quidem videtur et ab inscientibus. At vero magis ingredientibus hoc necessarium accidere. To suppose, on the other hand, that these things were in being throughout all previous time without there being any motion appears unreasonable on a moment’s thought, and still more unreasonable, we shall find, on further consideration. Si enim, aliis quidem mobilibus existentibus, aliis autem motivis, aliquando quidem erit aliquod primum movens, aliquid autem quod movetur, aliquando quidem nihil, sed quiescit; oportet hoc mutari prius. For if, while there are things that are movable and things that are motive, there is a time when there is a first mover and a first moved and another time when there is no such thing, but only something that is at rest, then what is at rest must previously have been in process of change. Erat enim aliquid causa quietis: quies enim privatio motus est. Quare ante primam mutationem erit mutatio prior. And there must have been some cause of its rest, rest being the privation of motion. Therefore, before this first change, there will be a previous change. Alia quidem enim movent singulariter, alia autem et secundum contrarios motus: ut ignis quidem calefacit, frigefacit autem non; scientia autem videtur contrariorum esse una. For some things cause motion singularly, while others can produce either of two contrary motions: fire causes heating but not cooling, while it would seem that knowledge may be directed to two contrary ends while remaining one and the same. Videtur igitur et ibi esse aliquid simili modo: frigidum enim calefacit conversum quodammodo et abscedens; sicut et peccat voluntarius sciens, quando e contrario utitur scientia. Even in the former class, however, there seems to be something similar, for a cold thing causes heating, in a sense, by turning away and retiring, just as one possessed of knowledge voluntarily makes an error when he uses his knowledge in the reverse way. Sed igitur quaecumque possibilia sunt facere aut pati aut movere, haec autem moveri, non penitus possibilia sunt; sed sic se habentia et proxima alterutris. But, at any rate, all things that are capable respectively of affecting and being affected, or of causing motion and being moved, are capable of it not under all conditions, but only when they are in a particular condition and approach one another. Quare, cum proximantur, aliud movet, aliud autem movetur; et cum sint ut sit hoc quidem motivum, illud vero mobile. It is on the approach of one thing to another that the one causes motion and the other is moved, and when they are present under such conditions as rendered the one motive and the other movable.