Ex quo sequitur quod si animal quandoque totaliter quiescat, quod in aliquo immobili incipiat esse motus cum prius non fuerit, non ex aliquo extrinseco movente, sed ab ipsomet quod movetur. Et si hoc potest esse in animali, nihil prohibere videtur quin idem accidat in universo: habet enim animal, et maxime homo, similitudinem quandam cum mundo: unde dicitur a quibusdam quod homo sit parvus mundus. Et sic si in parvo mundo incipit motus cum prius non fuerit, videtur quod etiam in magno mundo idem possit contingere. Et si hoc contingit in mundo, potest etiam contingere in toto infinito, quod quidam posuerunt extra mundum: si tamen sit aliquod infinitum quod possit quiescere et moveri. It follows from this that, if an animal is at one time entirely at rest, then motion begins to exist in an immobile being after previously not existing in it and the motion does not originate from an external mover, but from the very thing that is moved. And, if this can occur in an animal, there is nothing to prevent its occurring in the universe. For an animal, and especially man, possesses a likeness to the world; therefore, it is said that man is a small world. Accordingly, if, in this small world, motion can begin after previously not existing in it, it seems that the same can happen in the large world. And, if this happens in the world, it can happen in the infinite whole, which some assumed exists beyond the world—provided, of course, that there is something infinite that can rest and be moved. 1000. Deinde cum dicit: horum autem primum etc., solvit per ordinem rationes praemissas. In solutione ergo primae rationis dicit, quod istud recte dicitur, quod motus qui est inter contraria non potest semper durare unus et idem numero; quia forte hoc est necessarium, ut infra probabitur: et ideo ponit sub dubitatione, quia nondum erat probatum. Sed quia posset aliquis dicere quod etiam motus qui est inter contraria, potest esse semper unus numero propter identitatem mobilis, quod iterato de contrario in contrarium movetur; sicut si prius movebatur de albo in nigrum, postea moveatur de nigro in album, et sic semper: ideo subiungit quod non est possibile quod semper motus qui est unius et eiusdem mobilis, per reiterationem sit unus et idem. Et hoc manifestat per exemplum. Ponatur enim quod chorda citharae similiter se habeat; et movens qui percutit chordam, similiter se habeat in movendo: potest esse dubitatio, utrum unius chordae bis percussae sit unus et idem motus et sonus, aut semper alius et alius. Sed tamen quidquid sit de aliis mobilibus, nihil tamen prohibet quin aliquis motus qui non est inter contraria, sicut circularis motus, idem semper maneat continuus et perpetuus: quod magis ex sequentibus erit manifestum. Licet ergo omnis motus sit finitus secundum terminos, tamen per reiterationem aliquis motus potest esse continuus et perpetuus. 1000. Then, at of these objections (252b28), he answers these arguments in order. To the first, he says that it is correct to say that motion that occurs between contraries cannot always endure as one and the same numerical motion—for, as will be proven later, this may even be necessary. He leaves this in doubt because it has not yet been proved. But, because someone could say that even motion that is between contraries can be always numerically the same on account of maintaining the same mobile that is repeatedly moved from one contrary to another—for example, if it is first moved from white to black, and then from black to white, and so on throughout time—he then adds that it is not possible that a motion that is always in one and the same mobile be kept one and the same by repetition. And he explains this by an example. Let the same chord be continually struck on a lyre, and let the striker be unvarying in his striking; one may ask whether the motion and sound of the one chord struck twice is one and the same or continually different. Yet whatever be the case with other mobiles, there is nothing to prevent a motion that is not between contraries, such as a circular motion, from being the same continual and perpetual motion. This will be made clearer from later development. Therefore, although every motion is finite with respect to its termini, yet some motion can be continuous and perpetual by repetition. 1001. Deinde cum dicit: moveri autem quod non movetur etc.; solvit secundam rationem. Et dicit quod nullum inconveniens est si aliquid inanimatum incipiat moveri cum prius non moveretur, si hoc accidat propter hoc, quod movens extrinsecus aliquando sit praesens, aliquando non. Manifestum enim est quod oportet praeexistere motum ex parte moventis, quod aliquando fit prope cum prius non esset. 1001. Then, at as regards the second (253a2), he answers the second argument. And he says that there is nothing unsuitable in a non-living thing beginning to be moved when previously it was not being moved, provided that this occurs because an external mover is present at one time and not at another. For it is clear that motion must preexist on the part of a mover that at some time becomes near but previously was not so. Sed istud videtur esse inquirendum quasi dubium, scilicet si, existente movente, idem ab eodem quandoque moveatur, et quandoque non: hoc enim supra dixit non posse accidere, nisi praecedente aliqua mutatione, vel ex parte mobilis vel ex parte moventis: et sic semper praeexistit motus, sive praeexistat movens, sive non. Ideo autem hoc videtur quaerendum, quia ille qui hanc rationem induxit, de nullo alio videtur dubitare, quam propter quid quiescentia non semper quiescunt, et mobilia non semper moventur. However, this seems to be a point to be looked into as a problem, namely, whether, if a mover exists, the same object can be at one time moved by this mover and at another not. For he had previously said that such a thing cannot happen unless there intervenes some change affecting either the mover or the mobile. Accordingly, motion always preexists, whether or not a mover preexists. Now, this point seems to need investigation, because whoever proposed this argument seems to be certain about everything but one factor, namely, why it is that things at rest do not always rest and mobiles are not always in motion. 1002. Deinde cum dicit: maxime autem etc., solvit tertiam rationem. Et dicit quod id quod tertio obiectum est, maxime facit dubitare quod possit esse motus cum prius non fuerit, sicut videtur accidere in rebus animatis. Videtur enim quod animal quod prius quiescebat, postmodum moveatur processivo motu, nullo motu facto ab exteriori: et sic videtur quod illum motum animalis non praecedebat aliquis motus, neque in ipso animali neque in alio, sicut in rebus inanimatis dicebatur. 1002. Then, at the third objection (253a7), he answers the third argument. And he says that the third objection causes the greatest problem about whether motion can exist after previously not existing, based on what seems to happen in living things. For it seems that an animal that previously was at rest later begins to move about without any external cause of motion. Accordingly, it seems that that motion of the animal was not preceded by any motion, either in the animal or in anything else, as happens in non-living things. Sed hoc est falsum, scilicet quod motus animalis non fiat ab aliquo exteriori. Videmus enim semper in animalibus aliquid naturaliter motum, quod scilicet non movetur per voluntatem. Et huius quod movetur naturaliter, causa non est ipsum animal per suum appetitum: sed forsitan causa huius naturalis mutationis est continens, idest aer, et ulterius corpus caeleste; sicut manifeste apparet cum alteratur corpus animalis per calorem vel frigus aeris. But it is false that the motion of the animal does not come to be from something external. For we always observe in animals something naturally moved, not moved through will. And the cause of its being moved naturally is not the animal through its appetite, but perhaps the cause of this natural change is its surroundings, that is, the air, and beyond that the heavens, as is plainly the case when the body of an animal is altered by heat or coldness of air. Et dicit forsitan, quia in animali etiam aliquid naturaliter movetur ab interiori principio, sicut patet in mutationibus quae sunt in anima vegetabili, ut apparet in digestione cibi, et in sequentibus transmutationibus; quae dicuntur naturales, quia non sequuntur apprehensionem et appetitum. Et quia hoc videtur esse contra id quod est proprium animalis, scilicet quod moveat seipsum; ideo subiungit, quod cum dicimus animal movere seipsum, non intelligimus hoc de quolibet motu, sed de motu locali, secundum quem animal movet seipsum per apprehensionem et appetitum. And he says perhaps because, in an animal, something is also moved naturally by an internal principle, as is evident in those changes that occur in the vegetal soul, such as are the digestion of food and the subsequent changes, which are called “natural” because they do not follow upon apprehension and appetite. And, because this seems to be contrary to what is proper to an animal, which is to move itself, he adds that, when we say that an animal moves itself, we do not understand this of any and every motion, but of local motion, according to which an animal moves itself through apprehension and appetite. Sic igitur nihil prohibet, immo necessarium est, quod in corpore animalis fiant multae transmutationes a continente, scilicet aere et corpore caelesti; quarum quaedam movent intellectum aut appetitum, ex quo ulterius iam totum animal movetur. Accordingly, there is nothing to prevent many changes from taking place in the body of an animal on account of its surroundings, that is, the air and the heavens, some of which changes move the understanding or the appetite, by which in turn the whole animal is moved. Indeed, this is necessary. 1003. Est autem considerandum quod hic declarat modum quo corpora caelestia in nos agunt. Non enim agunt directe in animas nostras, sed in corpora: motis autem corporibus, per accidens fit motus in viribus animae quae sunt actus corporalium organorum; non autem ex necessitate in intellectu et in intellectivo appetitu, qui non utuntur organis corporeis. Aliquando tamen intellectus et voluntas sequuntur aliquas praedictarum mutationum; sicut cum aliquis per rationem eligit vel sequi vel repellere vel aliquid agere propter passionem, vel in corpore vel in parte sensitiva exortam. Et ideo non dicit quod omnes motus qui fiunt a continente moveant intellectum aut appetitum, sed quidam, ut omnino necessitatem ab intellectiva parte excludat. 1003. It should be noted that Aristotle here declares the way in which heavenly bodies act upon us. For they do not act directly on our souls, but on our bodies. But when our bodies are moved, then a change occurs per accidens in the powers of the soul, which are acts of bodily organs but not necessarily in the intellect and the intellective appetite, which do not use bodily organs. Yet the intellect and will sometimes follow upon some of these changes, as when a person, through his reason, chooses either to pursue or to reject or to do something on account of a passion that began in the body or in the sensitive part. Therefore, Aristotle does not say that all motions caused by the surroundings move the intellect or appetite, but that some of them do. In this way, he excludes necessity from the intellective powers. Ponit autem exemplum eorum quae dixerat, in dormientibus, in quibus maxima quies esse videtur quantum ad animales motus. Cum tamen in eis nullus motus sit sensibilis, idest a sensibili apprehensione procedens, iterum surgunt animalia evigilata, propter aliquem motum interius existentem, vel ex opere animae nutritivae, sicut cum digesto cibo deficiunt evaporationes quae somnum causabant, et animal excitatur; sive cum alteratur corpus a continente per calorem aut frigus. Of the things he said, he gives an example from sleeping things, in which there seems to be maximum rest with respect to animal motions. But, even though there be no motion during sleep that is sensible—that is, proceeding from sense apprehension—animals rise awakened by some motion existing within, due either to the work of the nutritive soul (as when, as a result of the food’s being digested, the vapors that caused sleep vanish and the animal is aroused), or when the body is altered by its surroundings, from heat or cold. Et sic diligenter consideranti apparet, quod nunquam in nobis aliquis motus apparet de novo, nisi praecedente aliquo alio motu. Et hoc promittit se in sequentibus magis manifestaturum. Thus, it is clear to anyone who considers the matter diligently that no motion ever newly appears in us unless some other motion preceded. And he promises to give a fuller explanation of this later. Lectio 5 Lecture 5 Dispositio rerum quantum ad motum et quietem qunique modis se habere potest excluduntur duo primi modi Things may be moved or at rest in five ways Principium autem considerationis est, quod quidem et dictae dubitationis, quare quaedam eorum quae sunt, aliquando quidem moventur, aliquando autem quiescunt iterum. Our enquiry will resolve itself at the outset into a consideration of the above-mentioned problem: what can be the reason that some things in the world at one time are in motion and at another are at rest again? Necesse autem aut omnia quiescere semper; aut omnia semper moveri; aut alia quidem moveri, alia autem quiescere. Now, one of three things must be true: either all things are always at rest, or all things are always in motion, or some things are in motion and others at rest. Et iterum horum aut quae moventur moveri semper, quae vero quiescunt quiescere semper; aut omnia apta nata sunt similiter moveri et quiescere; aut reliquum amplius et tertium est. Contingit enim alia quidem semper immobilia esse eorum quae sunt, alia vero semper moveri, alia autem cum utrisque accipere. In this last case again, either the things that are in motion are always in motion and the things that are at rest are always at rest, or they are all constituted so as to be capable alike of motion and of rest, or there is yet a third possibility remaining—it may be that some things in the world are always motionless, others always in motion, while others again admit of both conditions. Quod quidem nobis dicendum est: hoc enim habet solutiones omnium dubitatorum, et finis nobis est huius negotii. This last is the account of the matter that we must give, for herein lies the solution of all the difficulties raised and the conclusion of the investigation upon which we are engaged. Omnia igitur quiescere, et huius rationem quaerere dimittentes sensum, infirmitas quaedam est intellectus. To maintain that all things are at rest and to disregard sense perception in an attempt to show the theory to be reasonable would be an instance of intellectual weakness. Et de toto aliquo, sed non de parte ambiguitas est. Neque solum ad physicum, sed ad omnes scientias, ut ita dicam, et omnes opiniones; propter id quod motu utuntur omnes. It would call into question a whole system, not a particular detail; moreover, it would be an attack not only on the physicist, but on almost all sciences and all opinions, since motion plays a part in all of them. Amplius autem, de principiis importunitates sicut in rationibus circa doctrinas nihil sunt ad mathematicum, similiter autem in aliis: sic neque de eo quod nunc dicitur, ad physicum. Suppositio enim est quod natura principium motus sit. Further, just as in arguments about mathematics objections that involve first principles do not affect the mathematician—and similarly in the other sciences—so, too, objections involving the point that we have just raised do not affect the physicist, for it is a fundamental assumption with him that motion is ultimately referable to nature. Fere autem adhuc et omnia dicere moveri, falsum quidem, minus autem hoc praeter artem. Positum quidem enim est quod natura in physicis principium sit motus et quietis: similiter autem physicum est motus. The assertion that all things are in motion we may fairly regard as equally false, though it is less subversive of physical science. For though it was laid down in our course on physics that rest no less than motion is ultimately referable to nature herself, nevertheless motion is the characteristic fact of nature. Et dicunt quidam moveri eorum quae sunt, non alia quidem, alia vero non, sed omnia et semper; sed latere hoc nostrum sensum. Moreover, the view is actually held by some that not merely some things in the world are in motion and always in motion, but all things, though we cannot apprehend the fact by sense-perception. Ad quos etiam quidem non determinantes qualem motum dicunt, aut omnes, non difficile est contradicere. Although the supporters of this theory do not state clearly what kind of motion they mean, or whether they mean all kinds, it is no hard matter to reply to them. Neque enim augeri neque minui possibile est continue, sed est et medium. Thus we may point out that there cannot be a continuous process either of increase or of decrease: that which comes between the two has to be included. Est autem similis ratio huic de eo quod est guttam conterere, et nascentia lapides scindere. Non enim si tantum effodit aut removit gutta, et medium in medio tempore prius: The theory resembles that about the stone being worn away by the drop of water or split by plants growing out of it: if so much has been extruded or removed by the drop, it does not follow that half the amount has previously been extruded or removed in half the time. sed sicut navis tractus est, et guttae tot tantum movent, pars autem illarum in nullo tempore tantum. The case of the hauled ship is exactly comparable, for here we have so many drops setting so much in motion, but a part of them will not set as much in motion in any period of time. Dividitur enim quod remotum est in plura; sed nihil eorum motum est seorsum, sed simul. The amount removed is, it is true, divisible into a number of parts, but no one of these was set in motion separately: they were all set in motion together. Manifestum igitur quod non est necessarium semper aliquid abire, quia diminutio in infinita; sed totum aliquando abire. It is evident that, from the fact that the decrease is divisible into an infinite number of parts, it does not follow that some part must always be passing away; it all passes away at a particular moment. Similiter autem et in alteratione qualibet. Non enim si partibile in infinitum est quod alteratur, propter hoc et alteratio: sed velox fit multoties, sicut congelatio. Similarly, too, in the case of any alteration whatever, if that which suffers alteration is infinitely divisible, it does not follow from this that the same is true of the alteration itself, which often occurs all at once, as in freezing. Amplius, cum infirmetur aliquis, necesse est tempus fieri in quo sanabitur, et non in termino temporis mutari: necesse autem in sanitatem mutari, et in aliud nullum. Again, when any one has fallen ill, there must follow a period of time in which his restoration to health is in the future. The process of change cannot take place in an instant, yet the change cannot be a change to anything else but health. Quare dicere continue alterari, multum in manifestis est ambigere: in contrarium enim alteratio. The assertion that alteration is continuous is therefore an extravagant calling into question of the obvious: for alteration is a change from one contrary to another. Atque lapis neque durior fit neque mollior. Moreover, we notice that a stone becomes neither harder nor softer. Et secundum quod fertur, mirabile est si latuit lapis deorsum latus, aut manens in terra. Again, in the matter of locomotion, it would be a strange thing if a stone could be falling or resting on the ground without our being able to perceive the fact. Amplius autem, terra et aliorum unumquodque ex necessitate permanent quidem in propriis locis, moventur autem violenter ex his. Si igitur quaedam ipsorum sunt in propriis locis, necesse neque secundum locum omnia moveri. Quod igitur impossibile sit aut semper omnia moveri aut semper omnia quiescere, ex his et aliis huiusmodi sciet utique aliquis. Further, it is a law of nature that earth and all other bodies should remain in their proper places and be moved from them only by violence. Thus, from the fact that some of them are in their proper places, it follows that, in respect of place also, all things cannot be in motion. These and other similar arguments, then, should convince us that it is impossible either that all things are always in motion or that all things are always at rest. 1004. Postquam Philosophus in septimo ostenderat quod in moventibus et in mobilibus non est procedere in infinitum, sed est devenire ad aliquod primum; et hic iam ostendit quod motus semper fuit et semper erit; ulterius procedit ad inquirendum conditionem primi motus et primi motoris. 1004. Having shown in book 7 (242a15) that there is not an infinite process in movers and in mobiles, but that a first must be reached, and having now shown that motion has always been and always will be, the Philosopher goes on further to consider the condition of the first motion and of the first mover. Et dividitur in partes duas: And his treatment is divided into two parts.