Lectio 1 Lecture 1 Necesse est omne quod movetur ab aliquo alio moveri Whatever is moved must be moved by another Omne quod movetur, necesse est ab aliquo moveri. Si igitur in seipso non habet principium motus, manifestum est quod ab altero movetur: aliud enim erit movens. Everything that is in motion must be moved by something. For if it has not the source of its motion in itself, it is evident that it is moved by something other than itself, for there must be something else that moves it. Si autem in seipso, accipiatur AB, quod moveatur secundum se, et non eo quod eorum quae huius sunt, aliquid movetur. If, on the other hand, it has the source of its motion in itself, let AB be taken to represent that which is in motion primarily and according to itself and not in virtue of the fact that something belonging to it is in motion. Primum igitur, opinari AB a seipso moveri, propter id quod totum movetur, et a nullo exteriorum, simile est sicut si quis, ipso DE movente EZ, et ipso moto, opinetur DEZ a seipso moveri, propter id quod non videtur utrum ab utro moveatur, et utrum DE ab EZ, aut EZ a DE. In the first place, if we were to assume that AB is moved by itself because it is in motion as a whole and is not moved by anything external to itself, this assumption is just as if, supposing that KL is moving LM and is also itself in motion, we were to deny that KM is moved by anything because it is not evident which is the part that is moving it and which the part that is moved. Amplius, quod a seipso movetur, nullo modo pausabit cum movetur, in stando aliquid alterum quod movetur. Necesse est ergo, si aliquid pausat quod movetur, in stando aliquid alterum, hoc ab altero moveri. In the second place, that which is in motion without being moved by anything does not necessarily cease from its motion because something else is at rest, but a thing must be moved by something if the fact of something else having ceased from its motion causes it to be at rest. Hoc autem manifesto facto, necesse est omne quod movetur, moveri ab aliquo. Quoniam enim acceptum est AB moveri, divisibile erit: omne enim quod movetur, divisibile est. Dividatur igitur in C. Thus, if this is accepted, everything that is in motion must be moved by something. For AB, which has been taken to represent that which is in motion, must be divisible, since everything that is in motion is divisible. Let it be divided, then, at C. Necesse igitur, BC quiescente, quiescere et AB. Si enim non, accipiatur moveri. BC igitur quiescente, movebitur utique AC. Non ergo movetur per se AB. Sed concessum est per seipsum moveri primum. Now, if BC is not in motion, then AB will not be in motion, for if it is, it is clear that AC would be in motion while BC is at rest, and therefore, AB is not being moved per se. But it was hypothesized that AB is in motion primarily and per se. Manifestum igitur quod BC quiescente, quiescet et AB: et tunc pausabit quod movetur. Sed si aliquid in quiescendo aliud, stat et pausat moveri, hoc ab altero movetur. Manifestum est igitur quod omne quod movetur, ab aliquo movetur. Divisibile enim est omne quod movetur, et parte quiescente, quiescit totum. Therefore, if BC is at rest, AB must rest. But we have agreed that that which is at rest if something else is not in motion must be moved by something. Consequently, everything that is in motion must be moved by something, for that which is in motion will always be divisible, and if the part rests, the whole rests. 884. Postquam Philosophus in praecedentibus libris determinavit de motu secundum se, et de consequentibus ad ipsum, et de partibus eius, hic incipit determinare de motu per comparationem ad motores et mobilia. 884. After discussing motion in itself, the concomitants of motion, and the division of motion into parts in the preceding books, the Philosopher now begins to treat of motion in its relationship to movers and mobiles. Et dividitur in partes duas. The treatment falls into two parts. In prima ostendit esse primum motum et primum motorem. In the first, he shows that there is a first motion and a first mover. In secunda inquirit qualis sit motus primus et primus motor; et hoc in octavo libro, ibi: utrum autem factus sit aliquando etc. In the second, he investigates the properties of the first motion and of the first mover in book 8, at it remains to consider (250b11; [965]). Prima autem pars dividitur in partes duas. The first part is divided into two sections. In prima parte ostendit esse primum motum et primum motorem. In the first, he shows that there is a first motion and a first mover. Et quia ea quae sunt unius ordinis, habent aliquam comparationem ad invicem, ideo in secunda parte determinat de comparatione motuum ad invicem, ibi: dubitabit autem utique etc. And because things that belong to one order have some comparison to each other, therefore in the second part, he compares the various types of motion, at a difficulty may be raised (248a10; [928]). Circa primum tria facit: About the first, he does three things: primo praemittit quoddam quo indiget ad propositum ostendendum; first, he mentions the preliminary notes needed for proving the proposition; secundo ostendit propositum, ibi: quoniam autem omne quod movetur etc.; second, he proves the proposition, at since everything (242a15; [891]); tertio manifestat quoddam quod supposuerat, ibi: primum autem movens etc. third, he proves something he took for granted, at the first mover, not as the cause (243a32; [879]). 885. Proponit ergo primo quod necesse est omne quod movetur, ab aliquo alio moveri. Quod quidem in aliquibus est manifestum. Sunt enim quaedam quae non habent in seipsis principium sui motus, sed principium motus ipsorum est ab extrinseco, sicut in his quae per violentiam moventur. 885. He thus proposes first (241b34) that everything that is being moved must be moved by some other. In some cases, this is indeed evident, for there are some things that do not possess in themselves the principle of their motion; rather the principle of their motion is from without, as in things that are being moved by force. Si ergo aliquid sit quod non habeat in seipso principium sui motus, sed principium sui motus est ab extrinseco, manifestum est quod ab alio movetur. Si vero sit aliquod mobile quod habeat in seipso principium sui motus, circa hoc potest esse dubium an ab alio moveatur. Therefore, if there is anything that does not have in itself the principle of its own motion but its principle of motion is from without, it is clear that it is being moved by some other. However, if there is a mobile that does have in itself the principle of its own motion, there could be doubt whether it too is being moved by some other. Et ideo circa hoc instat, ad ostendendum quod ab alio movetur. Si ergo aliquid tale ponatur non moveri ab alio, accipiatur mobile ab, cui quidem moveri conveniat secundum se et primo, non autem ex eo quod aliqua pars eius movetur. Accordingly, he devotes himself to showing that this type of mobile is being moved by some other. Therefore, if it is supposed that such a mobile is not being moved by some other, let AB be a mobile capable of being moved primarily and according to itself and not in the sense that some part of it is being moved; Sic enim non moveretur secundum se, sed secundum partem; oportet autem, si aliquid movet seipsum non motum ab altero, quod sit primo et per se motum; sicut si aliquid est calidum non ab alio, oportet quod sit primo et per se calidum. for then it would not be being moved according to itself, but according to a part. Now, it is necessary that, if something moves itself without having been moved by some other then it is moved primarily and per se; for example, if something is hot not from some other source, it must be primarily and per se hot. Hoc ergo dato, procedit ad propositum ostendendum dupliciter: With this in mind, he proceeds to prove his proposition in two ways: primo quidem excludendo illud, unde maxime videri posset quod aliquid non ab alio moveatur; first, by excluding the most evident case in which it would appear that something is not being moved by some other; secundo directe ostendendo quod nihil potest a seipso moveri, ibi: amplius quod a seipso movetur etc. second, by proving directly that nothing can be moved by itself, at in the second place (241b34; [886]). Id autem ex quo maxime videtur quod aliquid non moveatur ab alio, est quia non movetur ab aliquo exteriori, sed ab interiori principio. The most evident reason that it seems that something is not being moved by some other is that it is not being moved by something outside itself, but by an intrinsic principle. Dicit ergo primo, quod opinari quod ab moveatur a seipso propter hoc quod totum movetur, et non movetur ab aliquo exteriori, simile est ac si aliquis diceret quod mobile, cuius una pars movetur et alia movet, moveat seipsum, propter hoc quod non discernitur quae pars sit movens, et quae sit mota; sicut si huiusmodi mobilis quod est dez, pars quae est de, moveat partem quae est ez, et non videatur quae pars earum sit movens et quae sit mota. He says first (241b24) that to believe that AB is being moved by itself because the whole is being moved—and this without being moved by anything outside of it—is like saying that, when one part of a whole is being moved and another part causes it to be moved, it is moving itself, because it is not evident which part is the mover and which is being moved. Such would be the case if a mobile DEZ is such that one part DE moves the part EZ and it is not seen which part moves the other and which is being moved. Vult autem per primum mobile ab, quod totum movetur et a principio interiori movente, intelligi aliquod corpus animatum, quod totum movetur ab anima: per mobile autem dez vult intelligi corpus aliquod quod non totum movetur, sed una pars eius corporalis est movens, et alia mota; in quo quidem mobili manifestum est quod id quod movetur, ab alio movetur. When he speaks of the first mobile AB as being moved as a whole by an intrinsic principle of motion, he means a living body that is, as a whole, being moved by the soul; but, when he speaks of the mobile DEZ, he means some body that is not being moved as a whole, but one bodily part of it is the mover and another the moved. In this latter case, it is evident that what is being moved is being moved by some other. Et ex hoc vult simile ostendere de corpore animato, quod videtur movere seipsum. Hoc enim ei convenit inquantum una pars aliam movet, scilicet anima corpus, ut in octavo plenius ostendetur. From this latter case, he wants to prove of a living body that seems to move itself that it too is being moved by some other. For it seems to move itself inasmuch as one part moves another, that is, as the soul moves the body, as will be more fully explained in book 8. 886. Deinde cum dicit: amplius quod etc., ostendit directe quod omne quod movetur ab alio movetur, tali ratione. Omne quod movetur a seipso, non quiescit a suo motu per quietem cuiuscumque alterius mobilis. Et hoc accipit quasi per se notum. Ex hoc autem ulterius concludit, quod si aliquod mobile quiescit ad quietem alterius, quod hoc movetur ab altero. Hoc autem supposito, concludit quod necesse est omne quod movetur ab aliquo alio moveri. Et quod hoc sequatur ex praemissis, sic probat. 886. Then, at in the second place (241b34), he proves directly that whatever is being moved is being moved by some other. This is his argument. Nothing that is being moved by itself rests from its motion on account of some other mobile’s resting. (He takes this as per se known.) From this, he further concludes that, if a mobile rests on account of the rest of another, then the mobile is moved by another. On this ground, he concludes that whatever is being moved is necessarily being moved by some other. And that this follows from the premises he now proves. Illud mobile quod supposuimus a seipso moveri, scilicet ab, oportet divisibile esse, quia omne quod movetur est divisibile, ut supra probatum est. Quia ergo divisibile est, nullum inconveniens sequitur si dividatur. Dividatur ergo in puncto c, ita quod una pars eius sit bc, et alia ac. That mobile that we have supposed as being moved by itself (that is, AB) must be divisible, for whatever is being moved is divisible, as was proved above. Hence, because it is divisible, nothing prevents it from being divided. Therefore, let it be divided at the point C such that one part of it is BC and the other part AC. Si ergo bc est pars eius quod est ab, necesse est quod quiescente bc parte, quiescat totum ab. Si ergo non quiescat totum, quiescente parte, accipiatur quod totum moveatur, et una pars quiescat: Now, if BC is part of AB, then, when the part BC rests, the entire AB must rest. But if, upon the part resting, the whole does not rest, let us grant that the whole is being moved and one part is at rest. sed quia una pars ponitur quiescere, non poterit poni totum moveri, nisi ratione alterius partis. Sic ergo bc quiescente, quod est una pars, movetur ac, quod est alia pars. Sed nullum totum cuius una sola pars movetur, movetur primo et per se. But, because we have assumed that one part is resting, the whole could not be granted as being moved except by reason of the other part. Therefore, when BC (which is one part) is at rest, the other part AC is being moved. But no whole of which one part only is being moved is being moved primarily and according to itself. Non ergo movebitur ab primo et per se, quod erat suppositum. Ergo oportet quod bc quiescente, quiescat totum ab. Therefore, AB is not being moved primarily and according to itself, as we originally assumed. Therefore, while BC is at rest, the entire AB must be at rest.