Authors/Thomas Aquinas/physics/L8/lect13

Lecture 13 The first mover perpetual and wholly unmoved, as shown from moving principles

Latin	English
	Lecture 13 The first mover perpetual and wholly unmoved, as shown from moving principles
lib. 8 l. 13 n. 1 Postquam philosophus ostendit quod primum movens est perpetuum et omnino immobile, ratione sumpta ex perpetuitate generationis et corruptionis animalium, quae movent seipsa; hic intendit idem ostendere, ratione sumpta ex principiis moventibus. Et circa hoc tria facit: primo commemorat ea quae dicta sunt a principio huius tractatus; secundo ex praemissis accipit rationem ad propositum, ibi: ex quibus est scire etc.; tertio concludit solutionem cuiusdam dubitationis supra motae, ibi: manifestum igitur factum est ex dictis et cetera.	1077. After showing that the first mover is perpetual and utterly immobile on account of the perpetuity of the generation and perishing of animals, which move themselves, the Philosopher now intends to prove the same with an argument based on the moving principles. About this he does three things: First he reviews things said from the beginning of this treatise; Secondly, from these he forms an argument for his proposition, at 1081; Thirdly, he finishes the solution of a doubt mentioned above, at 1085.
lib. 8 l. 13 n. 2 Circa primum tria resumit: primo destructionem quarundam improbabilium positionum. Et dicit quod non solum ex praemissis potest aliquis scire quod est aliquod primum movens immobile, sed etiam per considerationem principiorum motus. Et sicut supra dictum est, manifestum est ad sensum quod in rebus naturalibus inveniuntur quaedam, quae aliquando moventur et aliquando quiescunt. Et ex hoc manifestatum est supra quod nulla trium positionum est vera: neque illa quae dicit quod omnia moventur semper; neque illa quae dicit quod omnia quiescunt semper; neque illa quae dicit quod omnia quae quiescunt, quiescunt semper, et omnia quae moventur, moventur semper. Huius enim rei veritatem demonstrant illa quae sub utroque inveniuntur, scilicet motu et quiete, dum habent potentiam ut quandoque moveantur et quandoque quiescant.	1078. About the first he reviews three things: First (845 259 a23), the destruction of certain improbable positions. And he says that anyone can know that there is a first immobile. mover not only from the foregoing, but also by considering the principles of motion. And as was said above, it is evident to sense that among natural things are found some that are at one time being moved and at another time at rest. From this it was explained above that none of these three positions is true: the position that all things are always being moved; the position that all things are always at rest; and the position that all things which rest, always rest, and those being moved, are always being moved. The truth of this matter is demonstrated by the very things found under both, namely, under motion and under rest, since they have the potency to be moved at one time, and to be at rest at another.
lib. 8 l. 13 n. 3 Secundo ibi: quoniam autem huiusmodi etc., commemorat processum supra habitum ad investigandum primum motorem immobilem. Et dicit quod quia ista quae quandoque moventur et quandoque quiescunt, sunt omnibus manifesta: ne iterum aliquis sequeretur quartam positionem, ponens omnia entia esse huiusmodi ut quandoque moveantur et quandoque quiescant; volumus demonstrare duplicem naturam diversam, ostendentes scilicet quod quaedam sunt quae sunt semper immobilia, et iterum quod quaedam sunt quae semper moventur. Et circa hoc procedentes, proposuimus primo quod omne quod movetur, movetur ab aliquo; et quod necesse est hoc a quo aliquid movetur, aut esse immobile aut moveri; et si movetur, aut a seipso aut ab alio. Et cum non sit procedere in infinitum ut ab alio moveatur, oportet devenire ad hoc quod sit quoddam primum principium motus: ita quidem quod in genere eorum quae moventur, est primum principium quod movet seipsum; sed ulterius simpliciter inter omnia, primum principium est quod est immobile. Nec debet reputari inconveniens quod aliquid moveat seipsum: quia videmus manifeste esse multa talia in genere animatorum et animalium.	1079. Secondly, he recalls the process he went through when investigating the first immobile mover. And he says that because things which at one time are being moved and at another time are at rest are plain to all, lest anyone follow a fourth position that all beings are such that they are at one time being moved and at another time at rest, we want to demonstrate two differing natures by showing, namely, that there are certain things that are always immobile, and certain things again that are always being moved. And in dealing with this matter we proposed first that whatever is being moved is being moved by something and that this thing by which something is being moved is either immobile or is itself being moved, and if it is being moved, then either by itself or by another. And since one cannot proceed to infinity in the series of “being moved by another,” we must come to this that there is some first principle of motion, such that in the genus of things that are moved there is a first principle which moves itself, and beyond that, absolutely among all, there is a first principle which is immobile. Nor ought it to be thought strange that something move itself, because we plainly see many such in the genus of living things and animals.
lib. 8 l. 13 n. 4 Tertio ibi: haec autem et opinionem etc., commemorat quandam obiectionem supra positam et solutam. Cum enim probasset motus perpetuitatem, posuit obiectionem in contrarium ex rebus animatis, quae cum prius quieverunt, incipiunt quandoque moveri. Et hoc est quod hic dicit, quod ista animata quae movent seipsa, videbantur opinionem inducere quod contingit in toto universo motum fieri cum prius non fuerit; propter hoc quod videmus in eis hoc contingere, quod cum prius non moverentur, incipiunt quandoque moveri. Et ad huius solutionem oportet hic accipere, quod animalia movent seipsa secundum unum motum, scilicet secundum motum localem: hic enim solus motus invenitur in animalibus appetitui subiectus. Et tamen nec secundum hunc motum proprie animalia seipsa movent, ita scilicet quod huius motus alia causa non praeexistat. Non enim animali ex seipso est prima causa quod localiter moveatur: sed praecedunt alii motus, non voluntarii, sed naturales, vel ab interiori vel ab exteriori, secundum quos animalia non movent seipsa; sicut patet de motu augmenti et decrementi et respirationis, secundum quos motus animalia moventur, quamvis quiescant secundum motum localem, quo moventur a seipsis. Horum autem motuum naturalium causa est vel continens extrinsecum, scilicet caelum et aer, a quo immutantur corpora animalium exterius; vel aliquid intrans corpora animalium, sicut aer intrat per respirationem, et alimentum intrat per comestionem et potum. Et ex huiusmodi transmutationibus, sive ab interiori sive ab exteriori causatis, contingit quod animalia quandoque incipiunt moveri, cum prius non moverentur; sicut patet ex transmutatione quae est circa alimentum: quia dum decoquitur alimentum, propter vapores resolutos animalia dormiunt; sed quando alimentum est iam digestum et dissolutum, vaporibus residentibus, evigilant animalia et surgunt et movent seipsa motu locali; cum tamen primum principium motionis sit aliquid extrinsecum a natura animalis quod movet seipsum. Et inde est quod animalia non semper moventur a seipsis: quia respectu uniuscuiusque animalis moventis seipsum, invenitur aliquod aliud prius movens, quod movetur et movet. Si enim esset omnino immobile, semper eodem modo se haberet in movendo: et ita etiam motus animalis esset sempiternus. Sed quia hoc movens extraneum quod movet animalia, etiam ipsum movetur, non semper eodem modo movet. Unde nec animalia semper eodem modo movent seipsa, quia in his omnibus primum movens quod est causa animali movendi seipsum, sicut anima, sic movet quod movetur, non quidem per se sed per accidens: quia corpus mutatur secundum locum, mutato autem corpore, mutatur, et id quod in corpore existit, per accidens, scilicet anima. Et sic ex necessitate mutatur totum movens seipsum, ut non sit in eadem dispositione movendi.	1080. Thirdly, at (847 259 b3) he recalls an objection mentioned and solved above. For since he had proved the eternity of motion, he cited to the contrary an objection based on living things which after having been at rest begin at a certain time to be moved. And what he says here is that those living things which move themselves seem to foster the opinion that in the entire universe motion begins after previously not having been, on the ground that we see this happen in things, namely, that they at one time begin to be moved, when previously they were not being moved. To solve this it is necessary to accept that animals move themselves with respect to one motion, namely, local motion; for only this motion, based on appetite, is found in animals. And yet animals do not properly move themselves even with respect to this motion as though another cause of this motion does not pre-exist. For no animal is of itself the first cause of being moved locally, but other motions precede—not voluntary but natural—either from within or from without, according to which the animals do not move themselves, as is plain in the motions of growth and decrease, and respiration, according to which animals are moved, although they rest with respect to local motion by which they are moved by themselves The cause of these local motions is either an extrinsic container—namely, the heavens and air—by which the bodies of animals are changed externally, or something enters the bodies of animals, as air enters through breathing and as food enters through eating and drinking. And from such transmutations, caused either from within or from without, it happens that animals at a certain time begin to be moved, when previously they were not being moved, as is plain from the change which arises from food: for while the food is undergoing heat the animals sleep on account of the vapors being broken down, but when the food is now digested and dissolved, and the vapors are left, the animals awaken and get up and move themselves from place to place. In all this, nevertheless, the first principle of motion is something extrinsic to the nature of the animal that moves itself. That is the reason why animals are not always moved by themselves, because with respect to any animal moving itself there is found some previous mover, which is being moved and causes motion. For if it were entirely immobile, it would always maintain itself in the same way in causing motion and, consequently, the motion also of the animal would be perpetual. But because this extrinsic mover that moves animals is itself moved, it does not always move in the same way. Hence, neither do animals always move themselves in the same way, because in all these things the first mover which is the cause of the animal’s moving itself, such as the soul, causes motion in such a way that it is itself being moved not per se but per accidens, for the body is changed with respect to place, and when the body has been changed, that which exists in the body, namely, the soul, is also changed per accidens, And thus the whole that moves itself is changed of necessity, so that it does not maintain itself in the same disposition for causing motion.
lib. 8 l. 13 n. 5 Deinde cum dicit: ex quibus est scire etc., ex praemissis ostendit propositum: et primo quod primum movens sit immobile; secundo quod primus motus sit sempiternus, ibi: at vero si aliquid est et cetera. Circa primum duo facit: primo ostendit propositum; secundo excludit quandam obiectionem, ibi: non est autem idem moveri secundum accidens et cetera. Dicit ergo primo, quod ex praemissis possumus scire quod si aliquod principium est movens immobile, quod tamen movetur secundum accidens, non potest facere continuum motum et sempiternum. Ista enim causa est assignata quare animalium animae non movent semper, quia moventur per accidens. Sed ostensum est supra quod necesse est motum universi esse continuum et sempiternum. Ergo necesse est primam causam moventem in toto universo esse immobilem, ita quod nec etiam secundum accidens moveatur. Sed sicut supra dictum est, in rebus naturalibus inveniri debet quidam motus immortalis et incessabilis, et quod totum ens, idest dispositio huius universi, maneat in sua dispositione et in eodem statu. Ex immobilitate enim principii quod ponitur manere immobile, sequitur quod totum universum habeat quandam permanentiam sempiternam, secundum quod continuatur primo principio immobili, recipiendo influentiam ab ipso.	1081. Then at (848 259 b20) from the foregoing he proves his proposition. First that the first mover is immobile; Secondly, that the first motion is perpetual, at 1083. About the first he does two things: First he proves the proposition; Secondly, he dismisses an objection, at 1082. He says therefore first (848 259 b20) that from the foregoing we can know that if some principle is an immobile mover nevertheless moved per accidens, it cannot cause a continuous and perpetual motion. For the reason assigned for saying that animals do not always move is that they are moved per accidens. But it has been shown above that the motion of the universe must be continuous and perpetual. Therefore, it is necessary that the first moving cause in the whole universe be immobile, in such a way as not to be moved even per accidens. But, as was said above, in natural things a motion that is immortal and unceasing ought to be found, and the disposition of this universe should be maintained in its disposition and in the same state. For from the immobility of the principle that is set down as remaining immobile, it follows that the entire universe has an eternal permanence, insofar as it is joined to the first immobile principle and receives an influence from it.
lib. 8 l. 13 n. 6 Deinde cum dicit: non est autem idem etc., excludit quandam obiectionem. Dixerat enim quod si aliquod movens movetur per accidens, non movet motu sempiterno. Hoc autem videtur habere instantiam, quia secundum eius positionem motus inferiorum orbium, puta solis et lunae et aliorum planetarum, sunt sempiterni; et tamen motores eorum videntur moveri per accidens, si sequamur ea quae superius dixit. Ea enim ratione dixit animam animalis per accidens moveri, quia corpus animalis movetur quodam alio motu ab exteriori principio, qui non est ab anima: similiter autem apparet quod orbis solis movetur quodam alio motu, quasi delatus ex motu primi orbis, secundum quod revolvitur ab oriente in occidentem; isto autem motu non movetur a proprio motore, sed e converso ab occidente in orientem. Hanc ergo obiectionem excludit, dicens quod moveri secundum accidens potest attribui alicui vel secundum seipsum, vel secundum alterum; et hoc non est idem. Motoribus igitur orbium planetarum attribui potest moveri per accidens, non ita quod ipsi per accidens moveantur, sed ita quod orbes ab eis moti per accidens moventur, delati ex motu superioris orbis. Et hoc est quod dicit, quod moveri per accidens ab altero, idest ratione alterius, inest quibusdam principiis caelestium motuum, quantum ad motores orbium qui moventur pluribus motibus, scilicet motu proprio et motu superioris orbis: sed alterum, scilicet moveri per accidens secundum seipsum, invenitur solum in corruptibilibus, sicut in animabus animalium. Et huius diversitatis ratio est, quia motores superiorum orbium non constituuntur in suo esse ex sua unione ad corpora, et eorum connexio est invariabilis; et ideo quamvis corpora orbium moveantur, ipsi non moventur per accidens: sed animae quae movent animalia, constituuntur in suo esse secundum unionem ad corpora, et variabiliter eis connectuntur; et ideo secundum transmutationem corporum ipsae etiam animae dicuntur per accidens mutari.	1082. Then at (849 259 b28) he excludes an objection. For he had said that if a mover is moved per accidens, it does not move with an undying motion. Now this seems to give rise to an objection, because, according to his position, the motions of the inferior orbs, such as the sun and moon and other planets are eternal, and yet their movers seem to be moved per accidens, if we follow what he had just said. For he said that the reason why the soul of an animal is moved per accidens is that the animal's body is moved by an external principle, which is not from the soul; in like manner, it appears that the orb of the sun is moved by some other motion as though carried along by the motion of the first orb, insofar as it revolves from east to west; this is not the way it is moved by its proper mover, but contrariwise, from west to east. He dismisses this objection, saying that “being moved per accidens” can be attributed to something either with respect to itself or with respect to something else, and this is not the same. Now “being moved per accidens” can be attributed to the movers of the orbs of the planets, not in the sense that these movers are moved per accidens, but that the orbs moved by them are moved per accidens in being influenced by the motion of the superior orb. And this is what he says, that “to be moved per accidens from another,” i.e., by reason of another, is attributed to certain principles of heavenly motions, in the case of the movers of the orbs which are moved by more than one motion, namely, by their own and by that of the superior orb. But the other case, that a thing be moved per accidens with respect to itself is found only in perishable things, as in the souls of animals. The reason for this diversity is that the movers of the superior orbs are not constituted existents through being united to bodies, and their connection with the latter is unvarying; and therefore, although the bodies of the orbs are moved, the motors are not moved per accidens. But the souls which move animals depend for their existence on being united to their bodies, and they are connected in a way subject to variation, and accordingly, as the bodies are affected by change, the souls themselves are said to be changed per accidens.
lib. 8 l. 13 n. 7 Deinde cum dicit: at vero si aliquid est etc., probat quod primus motus est sempiternus. Et hoc duabus rationibus: quarum prima dependet ex praemissis, et talis est. Motus qui non est semper, invenitur esse a motore qui movetur per se vel per accidens, ut ex praedictis patet: cum ergo primum movens sit immobile et perpetuum, ita quod nec per se nec per accidens movetur, necesse est quod primum mobile, quod movetur ab hoc motore penitus immobili, perpetuo moveatur. Est autem attendendum, quod supra probavit immobilitatem primi motoris, per perpetuitatem motus supra ostensam: hic autem e converso, per immobilitatem primi motoris probat perpetuitatem motus: esset autem sua probatio circularis, si de eodem motu intelligeret. Unde dicendum est quod supra probavit immobilitatem primi motoris ex perpetuitate motus in communi; unde dixit quod in his quae sunt, est incessabilis quidam et immortalis motus: hic autem per immobilitatem primi motoris probat perpetuitatem primi motus. Ex quo manifestum est falsum esse quod Commentator dicit, quod supra in principio huius octavi probavit motum primum esse perpetuum.	1083. Then at (850 259 b32) he proves that the first motion is perpetual. And he does this with two arguments, the first of which depends on the foregoing and is this: A motion which is not perpetual is found to be from a mover that is moved per se or per accidens, as is evident from above. Since, therefore, the first mover is immobile and perpetual, and is moved neither per se nor per accidens, then, necessarily, the first mobile, which is moved by this utterly immobile mover is moved with a perpetual motion. Now, it should be noted that above he proved the immobility of the first mover by means of the perpetuity of motion, shown above. Here, on the contrary, through the immobility of the first mover he proves the perpetuity of motion, But this would be arguing in a circle, if the same motion were meant in both arguments. Hence it must be said that above he proves the immobility of the first mover from the perpetuity of motion in general; that is why he said that among the things that exist, there is an unceasing and immortal motion. But here through the immobility of the first mover he proves the perpetuity of the first motion. From which it is plain that what the Commentator says is false, namely, that in the beginning of this Book VIII Aristotle proved that the first motion is perpetual.
lib. 8 l. 13 n. 8 Secundam rationem ponit ibi: hoc autem est manifestum etc., quae sumitur ex perpetuitate generationis. Et dicit quod primum motum esse perpetuum, manifestum est etiam ex eo quod non est possibile aliter esse generationem et corruptionem et huiusmodi mutationes non temporales, nisi sit aliquid quod moveat et moveatur: quod enim omnis mutatio sit ab aliquo motore, iam supra ostensum est. Oportet ergo generationem et corruptionem et huiusmodi mutationes esse ab aliquo motore. Non autem possunt esse immediate a motore immobili, quia immobile semper movebit eundem motum et eodem modo; quia non mutabitur eius dispositio et habitudo ad mobile; manente autem eadem habitudine motoris ad mobile, semper manet idem motus. Non autem generatio et corruptio semper eodem modo sunt, sed quandoque aliquid generatur, quandoque corrumpitur: non ergo sunt immediate a motore immobili, sed a motore mobili. Quod autem movetur a motore moto, quod tamen movetur a motore immobili, in alternatione diversorum motuum potest habere perpetuitatem: quia propter id quod movens mobile aliter et aliter se habet ad res motas, non causabit eundem motum semper; sed magis, propter id quod in diversis locis (si moveatur motu locali) vel in diversis speciebus (si moveatur motu alterationis) causabit contrarium motum in aliis, et faciet quandoque quiescere, quandoque autem moveri. Dicit autem contrariis locis aut speciebus, quia nondum est probatum qua specie motus primum mobile moveatur; sed hoc infra inquiret. Sic igitur inquantum movetur, est causa diversitatis motuum; inquantum vero movetur a motore immobili, est causa perpetuitatis in hac mutationum diversitate. Ipsa ergo perpetuitas generationis ostendit primum motum esse perpetuum, et a motore immobili moveri. Est autem sciendum quod hae rationes, quibus Aristoteles probare nititur primum motum esse perpetuum, non ex necessitate concludunt: potest enim contingere absque omni mutatione primi motoris, quod non semper moveat, sicut supra ostensum est in principio huius octavi.	1084. The second argument is given at (851 260 a1) and is taken from the perpetuity of generation. And he says that the first motion is perpetual for another reason, namely, that the only way temporal generation and ceasing-to-be, and changes of this sort, can exist is that something move and be moved, for it has been proved above that every change is caused by some mover. Therefore, coming-to-be and ceasing-to-be and change of this kind ought to be from a mover, But they cannot be immediately from the immobile mover, because the immobile will always cause the same motion and in the same way, for its relation to the mobile is not variable; and, given a relation between mover and moved that remains the same, the motion remains always the same, However, coming-to-be and ceasing-to-be are not always in the same state, but at one time something is generated and at another it ceases to be. Therefore, these changes are not immediately from the immobile mover but from a mobile mover. Now, whatever is moved by a moved mover which in turn is moved by the immobile mover can retain perpetuity in spite of the alternation of diverse motions, because, since the mobile mover stands in varying relation to the things moved, it will not always cause the same motion. Rather, since it occupies differing positions (if moved with local motion), or assumes differing forms (if moved with a motion of alteration), it will produce a contrary motion in other things and will cause them to be at one time at rest and at another time in motion. He says “in contrary positions or forms,” because it has not yet been proved by what form of motion the first mobile is moved; but he will inquire into this later. Thus, therefore, insofar as it is moved, it is a cause of the diversity of motions; but insofar as it is moved by the immobile mover, it is the cause of the perpetuity in this diversity of changes. Therefore, the very perpetuity of generation shows that the first motion is perpetual and brought about by the immobile mover. But it should be understood that these arguments by which Aristotle tries to prove that the first motion is perpetual do not conclude of necessity, for it can happen without any change in the first mover that it not always cause motion, as was shown above in the beginning of this Book VIII.
lib. 8 l. 13 n. 9 Deinde cum dicit: manifestum igitur factum est etc., infert quandam conclusionem, quam supra dimiserat insolutam; scilicet quare quaedam moventur semper, et quaedam non semper. Et dicit quod huius causa manifesta est ex praemissis: quae enim moventur a motore immobili et perpetuo, moventur semper; quae autem moventur a motore mutato, non semper moventur: quia immobile, ut prius dictum est, cum simpliciter et similiter et in eadem dispositione maneat, movebit unum motum et simplicem.	1085. Then at (852 260 a11) he draws a conclusion which he left unsettled above, namely, why some things are always in motion and some not always. And he says that the cause of this is now plain from what has gone before: Things which are moved by an immobile and eternal mover are always in motion; things which are moved by a changed mover are not always in motion—for the immobile, as previously stated, since it remains absolutely alike and in the same state, will cause a motion that is one and simple.