Authors/Thomas Aquinas/physics/L5/lect1

Lecture 1 Per se motion is distinguished from per accidens

Latin	English
	Lecture 1 Per se notion is distinguished from per accidens
lib. 5 l. 1 n. 1 Postquam philosophus determinavit de motu et de his quae consequuntur motum in communi, hic iam accedit ad dividendum motum. Et dividitur in partes duas. In prima agit de divisione motus secundum quod dividitur in species; in secunda de divisione motus in partes quantitativas, et hoc in sexto libro, ibi: si autem est continuum et cetera. Prima autem pars dividitur in duas. In prima agit de divisione motus in suas species; in secunda agit de unitate et oppositione motus, ibi: post haec autem dicamus quid est simul et cetera. Prima dividitur in duas. In prima distinguit motum per se a motu per accidens; in secunda dividit motum per se in suas species, ibi: quoniam autem omnis mutatio et cetera. Prima dividitur in duas. In prima distinguit motum per se a motu per accidens; in secunda praetermittendum docet motum per accidens, et determinandum esse de motu per se, ibi: secundum quidem igitur accidens et cetera. Circa primum duo facit: primo distinguit motum per se a motu per accidens; secundo epilogat praedicta, ibi: quomodo quidem et cetera. Distinguit autem in prima parte motum per se a motu per accidens, tripliciter: primo quidem ex parte mobilis; secundo ex parte moventis, ibi: est autem et in movente etc.; tertio ex parte termini, ibi: quoniam autem est aliquid et cetera.	638. After discussing motion and the things that accompany motion in general, the Philosopher now undertakes to give various divisions of motion. And his treatment falls into two parts: In the first he divides motion into its species; In the second he divides motion into quantitative parts in Book VI. In the first he makes two parts: First he divides motion into its species; Secondly, he discusses unity and opposition of motion, at L. 5. The first is divided into two sections: In the first he distinguishes motion per se from per accidens; In the second he divides motion into its species, at L. 2. The first is divided into two parts: In the first he distinguishes per se motion from per accidens; In the second he shows that per accidens need not be discussed but that per se motion must, at 647. In regard to the first he does two things: First he distinguishes per se from per accidens motion; Secondly, he makes a summary at 646. In the first part he distinguishes per se motion from per accidens motion in three ways: First, on the side of the mobile; Secondly, on the side of the mover, at 640; Thirdly, on the side of the termini of motion, at 641.
lib. 5 l. 1 n. 2 Dicit ergo primo quod omne transmutans, idest transmutatum, tribus modis dicitur transmutari. Uno enim modo dicitur aliquid transmutari per accidens, sicut cum dicimus musicum ambulare, quoniam hic homo, cui accidit esse musicum, ambulat. Alio modo dicitur aliquid transmutari simpliciter, quia aliqua pars eius mutatur, sicut omnia quae dicuntur mutari secundum partes. Et ponit exemplum in motu alterationis: dicitur enim sanari corpus animalis, quia sanatur oculus aut thorax, idest pectus, quae sunt partes totius corporis. Tertio modo dicitur aliquid moveri, quod neque secundum accidens movetur, neque secundum partem, sed ex eo quod ipsum movetur primo et per se; ut per hoc quod dicit primo, excludatur motus secundum partem; per id quod dicit secundum se, excludatur motus per accidens. Hoc autem per se mobile variatur secundum diversas species motus; sicut alterabile est mobile secundum alterationem, et augmentabile secundum augmentum. Et iterum in specie alterationis differt sanabile, quod movetur secundum sanationem, et calefactibile, quod movetur secundum calefactionem.	639. He says therefore first (465 224 a1) that whatever changes, i.e., whatever is being changed, is described as doing so in three ways. First, per accidens, as when we say that a musician is walking, because the person who is walking happens to be a musician. Secondly, a thing is described as being changed without qualification even though only some part of it is changing, i.e., in statements which refer to part of the thing in question: thus the body is said to be restored to health, because the eye or the chest, which are parts of the body, are restored to health. Thirdly, there is the case of a thing that is in motion neither accidentally nor in respect of something that belongs to it as a part but in virtue of its being directly and per se in motion. And he says “directly” to exclude motion of a part, and per se to exclude motion that is per accidens. Now this per se mobile is a different thing according to the various kinds of motion: for example, it may be a thing capable of alteration—in which case it is called alterable—or it may be capable of growing—in which case it is called augmentable. Again, in the sphere of alteration it is called heal-able, if it is moved in respect of health, and heat-able, if it is moved in respect of heat.
lib. 5 l. 1 n. 3 Deinde cum dicit: est autem et in movente etc., distinguit motum per se a motu per accidens ex parte moventis. Et dicit quod similiter praedicta distinctio, quae posita est ex parte mobilis, potest attendi in movente. Tripliciter enim dicitur aliquid movere. Uno modo per accidens, sicut musicus aedificat. Alio modo secundum partem, inquantum aliqua pars eius movet, sicut homo dicitur percutere quia manus eius percutit. Tertio modo dicitur aliquid movere primo et per se, sicut medicus sanat.	640. Then at (466 224 a30) from the side of the mover he distinguishes per se from per accidens motion, And he says that the preceding distinctions which were posed from the side of the mobile can be found in the mover. For a thing is described in three ways as causing motion. First, per accidens, as “the musician is building”. Secondly, by reason of a part (when some part of the mover causes motion), e.g., the man is said to strike, because his hand strikes. In a third way, something is described as acting or moving directly and per se, as “the healer heals”.
lib. 5 l. 1 n. 4 Deinde cum dicit: quoniam autem est aliquid etc., procedit ad dividendum motum eodem modo ex parte termini. Et primo praemittit quaedam praeambula; secundo ponit divisionem, ibi: est autem et in illis et cetera. Circa primum tria facit: primo ponit quot requirantur ad motum; secundo comparat ea ad invicem, ibi: alterum enim est quod etc., tertio solvit quandam dubitationem, ibi: quid quidem igitur et cetera. Dicit ergo primo quod ad motum requiruntur quinque. Primo requiritur primum movens, a quo scilicet est principium motus. Secundo requiritur mobile quod movetur. Tertio, tempus in quo est motus. Et praeter ista tria requiruntur duo termini; unus scilicet ex quo incipit motus; et alius in quem motus procedit: omnis enim motus est a quodam in quiddam.	641. Then at (467 224 a34) looking at the terminus of motion, he divides motion once more in the same manner. First he lays down some presuppositions; Secondly, he gives his division, at 645. About the first he does three things: First he declares how many things are required for motion; Secondly, he mutually compares them, at 642; Thirdly, he settles a question, at 644. He says therefore (467 224 a34) that five things are needed for motion, First, there must be a first mover, i.e., a source from which the motion originates; secondly, a mobile that is being moved; thirdly, a time in which the motion occurs. In addition to these three are required the two termini; one from which the motion starts and another into which the motion tends; for every motion is from something into something.
lib. 5 l. 1 n. 5 Deinde cum dicit: alterum enim etc., comparat praemissa ad invicem. Et primo mobile ad duos terminos motus; secundo duos terminos motus ad invicem, ibi: magis autem in quod et cetera. Dicit ergo primo quod id quod primo et per se movetur, alterum est a termino in quem tendit motus, et a termino a quo motus incipit; sicut patet in istis tribus, lignum, calidum et frigidum. In motu enim calefactionis, lignum quidem est subiectum mobile, aliud vero, scilicet calidum, est terminus ad quem, aliud autem, scilicet frigidum, est terminus a quo. Dicit autem id quod movetur primum esse alterum ab utroque termino, quia nihil prohibet id quod movetur per accidens, esse alterum terminorum: subiectum enim, ut lignum, est id quod calefit per se; privatio vero et contrarium, ut frigidum, est quod calefit per accidens, ut in primo dictum est. Quod autem mobile sit alterum ab utroque termino, consequenter probat per hoc quod motus est in subiecto, sicut in ligno; non autem est in altero terminorum, neque in specie albi neque in specie nigri. Et hoc patet per hoc, quod illud in quo est motus, movetur: terminus autem motus neque movet neque movetur: sive terminus motus sit species, idest qualitas, ut in alteratione: sive sit locus, ut in motu locali; sive sit quantum, ut in motu augmenti et decrementi. Sed movens movet subiectum quod movetur, in quod movetur, idest in terminum ad quem. Quia ergo motus est in subiecto quod movetur, non autem in termino, manifestum est quod subiectum mobile est aliud a termino motus.	642. Then at (468 224 b1) he compares these five things: First he compares the mobile to the two termini; Secondly, he compares one terminus with the other, at 643, He says therefore (468 224 b1) that whatever is being moved directly and per se is distinct from the terminus into which the motion tends and from the terminus from which the motion begins, as is evident in these three things: wood, hot and cold. For in the motion called heating, the wood is the mobile subject, whereas the hot which is the terminus into which, is something else, as is the cold, which is the terminus from which. Now he says that what is moved directly is distinct from both termini, because there is nothing to prevent what is being moved per accidens from being either of the termini: for a subject, such as wood, is what becomes hot per se; but the privation, which is a contrary, namely, cold, is what becomes hot per accidens, as was explained in Book I. That the mobile is distinct from each terminus he proves on the ground that motion is in its subject, for example, in the wood, and not in either of the termini, i.e., not in the species “white” or in the species “black”. This is clear from the fact that that in which the motion exists is what is being moved. But the terminus of motion neither moves nor is moved: whether the terminus be a quality, as in alteration, or a place, as in local motion, or quantity, as in the motion called growing and decreasing. However, the mover moves the subject, which is being moved, into the terminus ad quem, Therefore, since motion exists in the subject being moved but not in the termini, it is clear that the mobile subject is distinct from the termini of the motion,
lib. 5 l. 1 n. 6 Deinde cum dicit: magis autem in quod etc., comparat utrumque terminorum ad invicem. Et dicit quod mutatio magis denominatur a termino ad quem, quam a termino a quo: sicut corruptio dicitur mutatio in non esse, quamvis illud quod corrumpitur mutetur ex esse; e contrario generatio est mutatio in esse, quamvis incipiat a non esse. Nomen autem generationis ad esse pertinet, corruptionis vero ad non esse. Huius autem ratio est, quia per mutationem aufertur terminus a quo, et acquiritur terminus ad quem: unde motus videtur repugnare termino a quo, et convenientiam habere cum termino ad quem; et propter hoc ab eo denominatur.	643. Then at (469 224 b7) he compares one terminus with the other. And he says that a change gets its name from the terminus ad quem rather than from the terminus a quo; for example, a change into non-being has the special name “corruption’, while, on the other hand, “generation” is the change into being, even though it starts from non-being. Consequently, the name “generation” pertains to being and “corruption” to non-being. The reason for this is that through change the terminus a quo is taken away, but a terminus ad quem is acquired: for which reason, motion seems to have a repugnance for the terminus a quo and a kinship to the terminus ad quem—that is why it gets its name from the latter.
lib. 5 l. 1 n. 7 Deinde cum dicit: quid quidem igitur motus sit etc., solvit quandam dubitationem. Et circa hoc tria facit. Primo praemittit duo quae ex praemissis sunt manifesta: quorum primum est quod in tertio dictum est quid sit motus; secundum est quod in praecedentibus immediate dictum est, quod species, idest qualitas, et locus et quaecumque passiones, idest passibiles qualitates, quae sunt termini motus, non moventur, cum in eis non sit motus, ut dictum est; ut patet in scientia, quae est quaedam species, et calore, qui est quaedam passio vel passibilis qualitas. Secundo ibi: et dubitabit aliquis etc., ponit tertium, de quo est dubitatio. Et dicit quod aliquis dubitare potest, utrum passiones, idest passibiles qualitates, ut calor et frigus et albedo et nigredo, ex quo non moventur, sint quidam motus. Tertio ibi: erit enim ad motum etc., ducit ad inconveniens, si hoc ponatur. Cum enim albedo sit terminus in quem est motus, si albedo sit motus, sequitur quod motus sit terminus motus, quod non potest esse, ut infra probabitur. Et ex hoc determinat veritatem, et dicit quod albedo non est motus, sed albatio. Addit autem fortassis, quia nondum probavit quod motus non terminetur in motum.	644. Then at (470 224 b10) he settles a doubt, About which he does three things: First, he mentions two things that are clear from the foregoing: first, that we have already pointed out in Book III what motion is; secondly, that in the immediately foregoing we have said that qualities and place and passible qualities that are the termini of motion are not themselves being changed, since there is no motion existing in them, as we have already said and as is clear from heat, which is a passible quality, and from science, which is a quality. Secondly, at (471 224 b13) he mentions a matter about which there is doubt, saying that someone may wonder whether passible qualities, such as heat and coldness and whiteness and blackness might not be types of motion, since none of them is a subject of motion. Thirdly, at (472 224 b14) he mentions a discrepancy that would arise if such a view were posited. For since whiteness is a terminus into which a motion tends, then if whiteness itself were a motion, it would follow that there is motion in the terminus of a motion, which cannot be, as will be proved later. And from this he arrives at the truth that it is not whiteness but whitening that is motion, But he adds “perhaps” because he has not yet proved that a motion cannot end up in a motion.
lib. 5 l. 1 n. 8 Deinde cum dicit: est autem et in illis etc., ex quo termini motus sunt aliud a mobili et a movente, ut ostensum est, ostendit quod praeter divisionem motus, quae accipitur ex parte moventis et mobilis, dividitur tertio motus ex parte termini. Et quia terminus ad quem magis denominat motum quam terminus a quo, ut dictum est, accipit divisionem motus non ex parte termini a quo, sed ex parte termini ad quem. Et dicit quod etiam ex parte illorum, scilicet terminorum, potest accipi in motu aliquid quod est per accidens, et aliquid quod est secundum partem et secundum aliud, et aliquid quod est primo et non secundum aliud. Per accidens quidem, sicut si dicatur de eo quod fit album, quod mutatur in id quod intelligitur vel cognoscitur ab aliquo, erit hoc per accidens: accidit enim colori albo quod intelligatur. Si autem dicatur de eo quod fit album, quod mutetur in colorem, hoc erit secundum partem: dicitur enim mutari in colorem, quia mutatur in albedinem, quae est pars coloris. Et simile est si dicam de aliquo qui vadit Athenas, quod vadit in Europam; quia Athenae sunt pars Europae. Si autem dicatur de eo quod fit album, quod mutatur in album colorem, hoc erit primo et per se. Non autem dividit motum ex parte temporis, quod videbatur residuum: quia tempus comparatur ad motum ut mensura extrinseca.	645. Then at (473 224 b16) from the fact that termini of motion are distinct from the mover and from the mobile, he shows that in addition to the divisions of motion taken on the side of the mover and of the mobile, there is a third, i.e., one taken on the side of the terminus. And since it is from the terminus ad quem rather than from the terminus a quo that motions are named, he develops his division not on the side of the latter but of the former. And he says that even on the side of the termini it is possible to find in motion (1) a goal that is so per accidens or (2) partially, i.e., with reference to a part or to something other than itself or (3) directly and not with reference to something else. And first of all, per accidens: when it is said of what is becoming white that it is being changed into something that can be understood or recognized by someone—that will be per accidens for it is accidental to the color white that it is recognized. But if it is said of what is becoming white that it is being changed into a color—this will be according to a part: for it is said to be changing into a color because it is becoming white, which is a part of the genus color. Likewise, if I should say of someone who is going to Athens that he is going to Europe, for Athens is a part of Europe. However, if it is said of what is becoming white that it is being changed into the color white, this will be directly and per se. The Philosopher does not divide motion from the viewpoint of time (which was one of the five things required for motion) because time is related to motion as an extrinsic measure.
lib. 5 l. 1 n. 9 Deinde cum dicit: quomodo quidem igitur per se etc., epilogat quod dixerat: et dicit quod manifestum est, quomodo aliquid per se movetur, et quomodo secundum accidens, et quomodo secundum aliquid aliud, idest secundum partem; et iterum, quomodo hoc quod dico primo et per se, invenitur tam in movente quam in mobili. Dictum est enim quid est movens primo et per se, et quid est quod movetur primo et per se. Et iterum dictum est quod motus non est in specie, idest in qualitate, quae est terminus motus; sed est in eo quod movetur, sive in mobili secundum actum, quod idem est.	646. Then at (474 224 b22) he summarizes what he has said. And he says that it is clear how something is in motion per se and how per accidens and how in respect of something not its entire self, i.e., in respect of a part, and again how what is referred to as directly and per se is found both in the mover and in the mobile, For it has been said what a direct and per se mover is and also what is being moved directly and per se. Finally, we have said that there is no motion in the quality which is the terminus of motion; rather motion is in what is being moved, i.e., in the actually mobile, which is the same thing.
lib. 5 l. 1 n. 10 Deinde cum dicit: secundum quidem igitur accidens etc., ostendit de quo motu sit agendum. Et primo ostendit propositum; secundo manifestat quoddam quod dixerat, ibi: ex medio autem et cetera. Dicit ergo primo quod mutatio quae est per accidens, dimittenda est: sive per accidens accipiatur ex parte moventis, sive ex parte mobilis, sive ex parte termini. Et hoc ideo quia motus per accidens est indeterminatus: est enim in omnibus sicut in terminis, et in omni tempore, et omnium subiectorum vel moventium; quia uni infinita possunt accidere. Sed mutatio quae non est secundum accidens, non est in omnibus; sed est tantum in contrariis et mediis, quantum ad motum qui est in quantitate, qualitate et ubi; et in contradictione, quantum ad generationem et corruptionem, quorum termini sunt esse et non esse: et hoc patet per inductionem. Sub arte autem non cadunt nisi ea quae sunt determinata; nam infinitorum non est ars.	647. Then at (475 224 b26) he shows which kind of motion needs to be discussed. First he states his proposition; Secondly, he explains something he said, at 648. He says therefore first that per accidens change will not be the subject of our discussion, whether it be per accidens on the side of the mover or of the mobile or of the terminus. The reason for this is that per accidens motion is indeterminate: for it is present in all things, in all termini, in all times, in all subjects and in all movers, and an infinity of things can be per accidens in something. But a change that is not per accidens is not found in all things; it is found only in situations (1) that involve contraries or the intermediate between contraries in respect to motions that affect quantity, quality and place, or (2) that involve contradictories, for example, generation and corruption, whose termini are being and non-being—and all this is evident by induction. Now art concerns itself only with things that are determinate, and there is no art to deal with the infinite.
lib. 5 l. 1 n. 11 Deinde cum dicit: ex medio autem mutatur etc., manifestat quoddam quod dixerat, scilicet quod motus sit in mediis. Et dicit quod contingit mutari ex medio ad utrumque extremorum et e converso, inquantum scilicet possumus uti medio ut contrario respectu utriusque extremi. Medium enim inquantum habet convenientiam cum utroque extremorum, est quodammodo utrumque eorum; et ideo potest dici hoc ad illud, et illud ad hoc: sicut si dicam quod media vox inter gravem et acutam est gravis ad ultimam, idest per comparationem ad acutam, et subtilis, idest acuta, per comparationem ad extremam, idest ad gravem; et fuscum est album per comparationem ad nigrum, et e converso.	648. Then at (476 224 b30) he explains his statement that motion can be in the intermediates. And he says that an intermediate may be a starting point of change and go to either of two contraries, inasmuch as we can take the intermediate as being contrary to both extremes. For the intermediate, inasmuch as it is akin to both extremes is in a sense either of them. Hence, we speak of the intermediate as in a sense contrary relatively to the extremes and of either extreme as a contrary relatively to the intermediate; for instance, the central note is low relatively to the highest and high relatively to the lowest, and grey is light relatively to black and dark relatively to white.