Authors/Thomas Aquinas/physics/L4/lect15

Lecture 15 Does time exist, and is there the same “now” in the whole of time?

Latin	English
	Lecture 15 Does time exist, and is there the same “now” in the whole of time?
lib. 4 l. 15 n. 1 Postquam determinavit de loco et vacuo, nunc determinat de tempore. Et primo dicit de quo est intentio, et quo ordine procedendum sit; secundo prosequitur propositum, ibi: quod quidem igitur et cetera. Dicit ergo primo quod consequens est ad praedicta, aggredi de tempore; in quo designat difficultatem considerationis. Et sicut de praemissis, ita et de tempore primo oportet opponendo procedere per rationes extraneas, idest ab aliis positas vel sophisticas: utrum scilicet sit tempus vel non; et si est, quae est natura eius. Deinde cum dicit: quod quidem igitur omnino non sit etc., prosequitur de tempore: et primo opponendo; secundo determinando veritatem, ibi: accipiendum autem et cetera. Circa primum duo facit: primo opponendo inquirit an tempus sit; secundo quid sit, ibi: quid autem sit tempus et cetera. Circa primum duo facit: primo ponit duas rationes ad ostendendum tempus non esse; secundo inquirit de nunc, utrum sit unum nunc in toto tempore vel plura, ibi: amplius autem ipsum nunc et cetera.	558. Having arrived at conclusions concerning Place and the Void, the Philosopher now concluded concerning Time. First he tells what his intention is and the order he will follow; Secondly, he carries out his proposal, at no. 559. He says therefore first [390 217 b29] that our plan now calls for us to “attack” time, by which he signifies how difficult the subject is. And as in previous discussions, so in the case of time one must begin by presenting extraneous reasons, i.e., the opinions of others, as well as sophistical arguments, dealing with the question of whether time exists or not and, if it does, what is its nature. Then [391 217 b32] he begins the discussion of time: First by arguing against [existence of time]; Secondly, by presenting the truth, at no. 571 (L.17). In regard to the first he does two things: First he inquires whether time exists, arguing against it; Secondly, what it is, at no. 565 (L.16). As to the first he does two things: First he gives two reasons which show that time does not exist; Secondly, he inquires about the “now”: asking whether there is one “now” in the whole of time or several, at no. 561.
lib. 4 l. 15 n. 2 Dicit ergo primo quod ex his duabus rationibus potest aliquis concipere, quod tempus vel omnino non sit, vel sit aliquid quod vix et obscure percipi possit. Prima ergo ratio talis est. Omne compositum ex his quae non sunt, impossibile est esse, vel habere aliquam substantiam. Sed tempus componitur ex his quae non sunt; quia temporis est aliquid praeteritum, et iam non est, aliud est futurum, et nondum est, et ex his duobus componitur totum tempus, infinitum et perpetuum positum. Ergo impossibile est tempus aliquid esse.	559. He says then [391 217 b32] that two reasons could lead us to suppose either that time does not exist at all or that it is something that can scarcely and only in an obscure way be conceived. Here is the first reason: anything that is composed of things which do not exist cannot have any existence or any substance; but time is composed of what does not exist—for part of time is the past which no longer exists, and the rest is the future, which does not yet exist (and these two things comprise the whole of time considered as infinite and everlasting). Therefore, it is impossible for time to be anything.
lib. 4 l. 15 n. 3 Secundam rationem ponit ibi: adhuc autem omnis etc.: quae talis est. Cuiuslibet divisibilis existentis necesse est esse, dum est, aliquam partem eius, aut aliquas. Sed tempus non est huiusmodi; quia quaedam partes temporis sunt iam praeteritae, aliae vero sunt futurae, et nihil temporis quod sit divisibile est in actu. Ipsum vero nunc, quod est in actu, non est pars temporis: quia pars est quae mensurat totum, ut binarius senarium; vel saltem ex qua componitur totum, sicut quaternarius est pars senarii, non mensurans ipsum, sed quia ex ipso et binario componitur senarius; tempus autem non componitur ex ipsis nunc, ut infra probabitur. Tempus igitur non est aliquid.	560. The second reason [392 218 a3] is as follows: As long as any divisible thing is existing there must exist some part of it or a number of parts. But time does not meet these requirements—for some parts of time are already past and others are in the future, so that no divisible part of time is actually existing. And the “now” which is actual is not a part of time: for a part is either a measure of a whole, as two is the measure of six, or at least it is a component of the whole, as four is a part of six (although not its measure) since from it and two, six is composed. Time however does not have “nows” as its parts, as will be proved later (Book VI). Therefore, time is not anything.
lib. 4 l. 15 n. 4 Deinde cum dicit: amplius autem ipsum nunc etc., inquirit utrum sit idem nunc in toto tempore. Et circa hoc tria facit: primo movet quaestionem; secundo obiicit ad unam partem, ibi: si quidem enim nunc etc.; tertio ad alteram, ibi: at vero neque nunc et cetera. Dicit ergo primo quod non est facile scire, utrum nunc, quod videtur distinguere inter praeteritum et futurum, semper maneat idem in toto tempore, an sit aliud et aliud.	561. Then [393 218 a8] he inquires whether there be the same “now” through the whole of time. About this he does three things: First, he raises the question; Secondly, he objects to one side of the question, at no. 562; Thirdly, he objects to the opposite side, at no. 563. He says therefore first that it is not easy to be certain whether the “now” which is seen to distinguish the past from the future always remains identical with itself throughout the whole of time or whether it is other and other.
lib. 4 l. 15 n. 5 Deinde cum dicit: si quidem enim nunc etc., ostendit quod non sit aliud et aliud nunc, tali ratione. Duae partes temporis quae sunt aliae ab invicem, non possunt simul esse, nisi una contineat aliam, sicut maius tempus continet minus, ut annus mensem, et mensis diem (simul enim est et dies et mensis, et mensis et annus). Sed unum nunc, cum sit indivisibile, non continet alterum: si ergo est accipere in tempore duo nunc, necesse est quod illud nunc quod prius fuit et modo non est, aliquando corrumpatur, et quod nunquam duo nunc sint simul. Omne autem corruptum necesse est in aliquo nunc corrumpi. Non autem potest dici quod prius nunc sit corruptum in ipso nunc priori, quia tunc erat ipsum nunc, et nihil corrumpitur dum est. Similiter etiam non potest dici, quod prius nunc corrumpatur in posteriori: quia impossibile est sic se habere duo nunc ad invicem, quod sint habita, idest immediate se consequentia, sicut etiam impossibile est de duobus punctis. Et hoc nunc supponatur, quia in sexto probabitur. Sic igitur inter quaelibet duo nunc sunt infinita nunc. Si ergo prius nunc corrumpatur in aliquo posteriori nunc, sequitur quod illud nunc quod est ante, simul sit cum omnibus nunc intermediis; quod est impossibile, ut dictum est. Impossibile est igitur esse aliud et aliud nunc.	562. Then [394 218 a11] he gives a reason to show that the “now” is not other and other. Two parts of time which are not the same cannot be existing together unless one contains the other, as a greater period of time contains a smaller, e.g., as a year contains the month and the month the day (for the day and the month and the year exist together). But one “now,” since it is indivisible, does not contain another. If, therefore, we are to accept two “now’s” in time, then that “now” which existed before the present one and no longer exists, ceased to be sometime, and so two “now’s” are never together. However, anything that ceased to be, did so in some “now.” But it cannot be that the prior “now” ceased to be in that prior “now,” because the prior “now” was existing then, and nothing ceases to be while it is. Likewise, it cannot be said that the prior “now” ceases to be in a later one: for it is impossible to have two “now’s” together as “had,” i.e., so as to follow immediately one upon the other, just as the same thing is impossible in the case of two points. (This is supposed now, but will be proved in Book VI). Thus, between any two “now’s” there are an infinity of “nows.” If, therefore, that prior “now” ceases to be in some later “now,” it follows that the prior “now” was existing along with all the intermediate “now’s”—which is impossible, as we have said. It is impossible, therefore, that the “now” be other and other.
lib. 4 l. 15 n. 6 Deinde cum dicit: at vero neque etc., ostendit quod non possit esse unum et idem nunc, duabus rationibus. Quarum prima talis est. Nullius divisibilis finiti potest esse unus terminus tantum; neque si sit continuum secundum unam dimensionem tantum, ut linea; neque si secundum plures, ut superficies et corpus. Nam unius lineae finitae termini sunt duo puncta, et superficiei plures lineae, et corporis plures superficies. Sed ipsum nunc est terminus temporis. Cum igitur sit accipere aliquod tempus finitum, necesse est ponere plura nunc.	563. Then [395 218 a21] he gives two reasons to show that there cannot be just one “now.” The first is that no finite divisible thing can have just one boundary; whether it be a divisible of one dimension, as a line; or of more than one dimension, as a plane or a solid. For the boundaries of one finite line are two points and of a surface the boundaries are several lines, and of a body several planes. But the “now” is a boundary of time. Since therefore it is possible to conceive of a finite time there must be more than one “now.”
lib. 4 l. 15 n. 7 Secundam rationem ponit ibi: amplius si simul esse etc.: quae talis est. Illa dicuntur esse simul secundum tempus, et nec prius nec posterius, quae sunt in eodem nunc: si igitur est idem nunc permanens in toto tempore, sequitur quod illa quae fuerunt ante mille annos, sint simul cum his quae sunt hodie. Ultimo autem epilogando concludit, tot opposita esse de ipsis nunc, quae sunt in tempore.	564. He gives a second reason [396 218 a25].Those things are said to be together in time, and neither previously nor later, which are in the same “now.” If therefore it is the same “now” that persevere throughout time, it follows that things which existed a thousand years ago are together with things that exist today. Summarizing, he concludes that these are the conflicting opinions about the “now’s” which exist in time.