Authors/Thomas Aquinas/physics/L4/lect16

Lecture 16 Dialectical inquiry into what time is, and how related to motion

Latin	English
	Lecture 16 Dialectical inquiry into what time is, and how related to motion
lib. 4 l. 16 n. 1 Postquam inquisivit an tempus sit, hic disputative inquirit quid sit. Et primo improbat positiones aliorum; secundo inquirit quomodo se habeat tempus ad motum, qui tempori propinquissimus videtur, ibi: quoniam autem videtur maxime et cetera. Circa primum duo facit: primo ponit opiniones aliorum de tempore; secundo improbat eas, ibi: quamvis circulationis et cetera. Dicit ergo primo quod quid sit tempus, et quid sit natura eius, non potest esse manifestum ex his quae tradita erant de tempore ab antiquioribus, neque per aliqua quibus attingi possit quid ipsi circa hoc determinaverint. Quidam enim dixerunt quod tempus est motus caeli; quidam vero quod est ipsa sphaera caelestis.	565. After inquiring whether time exists, the Philosopher now inquires dialectically what it is. First he disproves the opinions of others; Secondly, he inquires how time is related to motion, which seems to be something most akin to time, at no. 568. About the first he does two things: First he gives various opinions of others about time; Secondly, he disproves them, at no. 566. He says therefore first that what time is and what is the nature of time cannot be gathered from what is handed down from the earlier philosophers nor from any piecing together of what they concluded about it. For some said that time is a motion of the heavens; others that it is a heavenly sphere itself.
lib. 4 l. 16 n. 2 Deinde cum dicit: quamvis circulationis etc., improbat positas opiniones: et primo primam; secundo secundam, ibi: totius autem sphaera et cetera. Circa primum ponit duas rationes: quarum prima talis est. Si circulatio est tempus, oportet quod pars circulationis sit circulatio, quia pars temporis tempus est: sed pars circulationis non est circulatio: ergo tempus non est circulatio. Secundam rationem ponit ibi: amplius autem etc., quae talis est. Motus multiplicatur secundum multitudinem mobilium: si ergo plures essent caeli, plures essent circulationes eorum; et sic, si circulatio sit tempus, sequeretur quod essent multa tempora simul: quod est impossibile. Non enim est accipere duas partes temporis simul, nisi una contineat aliam, ut supra dictum est. Movebantur tamen hi ad ponendum tempus esse circulationem, quia videbant tempora circulo quodam reiterari.	566. Then [398 218 b1] he disproves their opinions, first of all, the first; then the second, at no. 567. In regard to the first opinion he gives two counter-arguments, of which the first is: If a circular revolution in time then part of that revolution is a circular revolution, because a part of time is time. But part of a circular revolution is not a circular revolution. Therefore time is not a circular revolution. Then [399 218 b3] he gives a second argument: The number of motions corresponds to the number of mobiles; if therefore there are many heavens, there are many circular revolutions. And thus if a circular revolution is time, there are many times together—which is impossible. For no two parts of time are together unless one contains the other, as we have said. (Those who posited time as a circular revolution were led to do so because they observed that times occur over and over in a kind of cycle.
lib. 4 l. 16 n. 3 Deinde cum dicit: totius autem sphaera etc., excludit secundam opinionem. Et dicit quod quibusdam visum est quod sphaera caeli esset tempus, propter hoc quod omnia sunt in tempore, et etiam omnia sunt in sphaera totius, quia caelum continet omnia: unde concludere volebant, quod sphaera caeli esset tempus. In qua quidem ratione duplex erat defectus: primo quidem quia non univoce dicitur esse aliquid in tempore et in loco; secundo quia argumentabantur in secunda figura ex duabus affirmativis. Et ideo dicit quod ista positio est magis stulta, quam quod oporteat considerare impossibilia quae ad ipsam consequuntur. Manifestum est enim quod omnes partes sphaerae sunt simul, non autem temporis.	567. Then [400 218 b5] he rejects the second opinion. And he says that some thought the sphere of the heavens in time, because all things are in time and all things are also in the sphere of the whole, because the heavens contain all things. Hence they wished to conclude that the sphere of the heavens is time. But there were two things wrong in their reasoning: first, because something is not said univocally as being in time and in place; secondly, because they were using two affirmative premises in a Second Figure syllogism. Therefore he says that their position is too foolish to consider the impossibilities that follow upon it. For it is clear that all the parts of the sphere exist simultaneously, whereas the parts of time do not.
lib. 4 l. 16 n. 4 Deinde cum dicit: quoniam autem videtur etc., inquirit quomodo se habeat tempus ad motum. Et primo ostendit quod tempus non est motus; secundo quod non est sine motu, ibi: at vero neque sine motu et cetera. Circa primum ponit duas rationes ad ostendendum quod tempus non sit motus aut mutatio, quod posset maxime videri. Quia omnis mutatio et motus vere est solum in ipso transmutato, vel etiam in loco ubi est transmutatum et transmutans. Quorum primum dicitur propter motum in substantia et quantitate et qualitate; secundum autem dicitur propter motum in ubi, qui dicitur motus in loco. Sed tempus est ubique et apud omnia: ergo tempus non est motus.	568. Then [401 218 b9] he inquires how time is related to motion. First he shows that time is not motion; Secondly that time does not exist independently of motion, at no. 570. In regard to the first he gives two reasons to show that time is not a motion or a change (for it certainly seems to be such). Here is his reason: Every change and motion is certainly only in the thing being changed or in the place where the changer and changed are. The first of these is mentioned because of motion in substance and quantity and quality; the second because of motion in the predicament “where,” called motion in place.” But time is everywhere and exists among all things. Therefore time is not a motion.
lib. 4 l. 16 n. 5 Secundam rationem ponit ibi: amplius autem mutatio etc.: quae talis est. Omnis mutatio et motus est velox aut tardus: sed tempus non est huiusmodi: ergo tempus non est motus vel mutatio. Mediam sic probat. Tardum et velox determinantur ex tempore: quia velox dicitur quod movetur per multum spatium in pauco tempore; tardum autem quod e converso per paucum spatium in multo tempore. Sed tempus non determinatur tempore, neque secundum suam quantitatem, neque secundum suam qualitatem; quia idem non est mensura sui ipsius. Ergo tempus non est neque velox neque tardum. Et quia proposuerat quod mutatio est velox aut tarda, non facta mentione de motu, subiungit quod quantum ad praesens, non differt dicere motum aut mutationem: in quinto enim ostendetur eorum differentia.	569. He gives the second reason [402 218 b13]: Every change and motion is either slow or fast; but time is not either. Therefore time is neither a motion nor a change. He explains the minor premise thus: Slow and fast are determined by time—because that is fast which is moved a great distance in a short time and that is slow which is moved a short distance in much time. But time is not determined by either according to its quantity or its quality, because nothing is its own measure. Therefore, time is neither slow nor fast. And since he had proposed that change is fast or slow, without mention of motion, he adds that for the present it does not matter whether one says “motion” or “change.” Their difference will be shown in Book V.
lib. 4 l. 16 n. 6 Deinde cum dicit: at vero, neque sine motu etc., ostendit quod tempus non est sine motu: quia quando homines non mutantur secundum suam apprehensionem, aut, si mutantur, tamen latet eos, tunc non videtur eis quod pertranseat aliquod tempus. Sicut patet in iis qui in Sardo, quae est civitas Asiae, dicuntur fabulose dormire apud heroas, idest apud deos. Animas enim bonorum et magnorum heroas vocabant, et quasi deos colebant, ut Herculis et Bacchi et similium. Per incantationes enim aliquas, aliqui insensibiles reddebantur, quos dicebant dormire apud heroas; quia excitati, quaedam mirabilia se vidisse dicebant, et futura quaedam praenunciabant. Tales autem ad se redeuntes, non percipiebant tempus quod praeterierat dum ipsi sic absorpti erant; quia illud instans primum, in quo dormire coeperant, copulabant posteriori nunc in quo excitabantur, ac si essent unum; medium enim tempus non percipiebant. Sicut igitur, si non esset aliud et aliud nunc, sed idem et unum, non esset tempus medium; sic et quando latet diversitas duorum nunc, non videtur tempus esse medium. Si ergo tunc accidit non opinari tempus, cum non percipimus aliquam mutationem, sed homini videtur quod sit in uno indivisibili nunc; tunc autem percipimus fieri tempus, quando sentimus et determinamus, id est numeramus, motum aut mutationem; manifeste sequitur quod tempus non sit sine motu, neque sine mutatione. Ultimo ergo concludit quod tempus non sit motus, neque sit sine motu.	570. Then [403 218 b21] he shows that although time is not motion, it is not independent of motion: for when men are not changing according to what they apprehend, they are changing without being aware of it, then it does not seem to them that time is passing. This is clear in the fable about the city in Asia called Sardo. In Sardo certain people were said to sleep among the Heroes, i.e., among the gods. For they called the souls of the good and the great “Heroes,” and worshipped them as gods, as in the case of Hercules and Bacchus and the like. Certain ones were rendered insensible by means of incantations and said to sleep among the gods, because then they awoke they claimed to have seen marvelous things and foretold future events. These persons, returning to themselves, were not aware of the time which elapsed while they were thus absorbed; because that first instant in which they began to sleep they joined to the instant in which they awoke, as if it were one instant—but the time that elapsed escaped them. Therefore just as there would be no intervening time between “now’s,” if the “now” of time were always the same and not other and other, so also when two “now’s” are fused in our apprehension, the elapsed time is not apprehended, and there seems to have been no intervening time. If, then, we are apt to think that no time has elapsed when we do not perceive any changes, and that we are in one and the same indivisible “now,” but we then perceive time to be elapsing when we sense and determine, i.e., motion and change, it clearly follows that time is not independent of motion and change. In summary he concludes that time is not motion, nor is it without motion.