Authors/Thomas Aquinas/physics/L7/lect4

Lecture 4 It is shown in alteration, and growth and decrease, that mover and moved are together

Latin	English
	Lecture 4 It is shown in alteration, and growth and decrease, that mover and moved are together
lib. 7 l. 4 n. 1 Postquam ostendit in motu locali, quod movens et motum sunt simul, ostendit idem in alteratione; quod scilicet nihil est medium alterantis et alterati. Et hoc probat primo per inductionem. In omnibus enim quae alterantur, manifestum est quod simul sunt ultimum alterans et primum alteratum. Videtur autem hoc habere instantiam in quibusdam alterationibus: sicut cum sol calefacit aerem sine hoc quod calefaciat orbes medios planetarum; et piscis quidam in reti detentus, stupefacit manus trahentis rete, absque hoc quod stupefaciat rete. Sed dicendum est quod passiva recipiunt actionem activorum secundum proprium modum; et ideo media quae sunt inter primum alterans et ultimum alteratum, aliquid patiuntur a primo alterante, sed forte non eodem modo sicut ultimum alteratum. Aliquid igitur patitur rete a pisce stupefaciente, sed non stupefactionem, quia eius non est capax: et orbes medii planetarum aliquid recipiunt a sole, scilicet lumen, non autem calorem.	909. After showing that the mover and moved are together in local motion, he shows the same for alteration, i.e., that there is nothing between the thing altered and the cause of the alteration. This he proves first by induction at (693 244 b2). For in all things that are altered, it is clear that the last thing altering, and the first thing altered, are together. However this seems to suggest a difficulty in certain alterations, e.g. when the sun heats the air without heating the intermediate orbs of the planets, or when a certain kind of fish held in a net shocks the hand of the one holding the net without shocking the net. To this it must be said that things which are passive undergo the action of things that are active in their own special way, and therefore the intermediate between the first cause of an alteration and the last thing altered undergo something from the first cause, but perhaps not in the same way as the last thing affected. For the net undergoes something from the fish that causes the shock, but not a shock, because it is not capable of being shocked. And the intermediate orbs of the planets receive something from the sun, namely, its light, but not its heat.
lib. 7 l. 4 n. 2 Secundo ibi: quale enim alteratur etc., probat idem per rationem: quae talis est. Omnis alteratio est similis alterationi quae fit secundum sensum: sed in alteratione quae est secundum sensum, alterans et alteratum sunt simul: ergo et in qualibet alteratione. Primum sic probat. Omnis alteratio fit secundum qualitatem sensibilem, quae est tertia species qualitatis. Secundum illa enim alterantur corpora, quibus primo corpora ab invicem differunt; quae sunt sensibiles qualitates: ut gravitas et levitas, durities et mollities, quae percipiuntur tactu; sonus et non sonus, qui percipiuntur auditu (sed tamen si sonus in actu accipiatur, est qualitas in aere, consequens aliquem motum localem; unde non videtur secundum huiusmodi qualitatem esse primo et per se alteratio: si vero sonus in aptitudine accipiatur, sic per aliquam alterationem fit aliquid sonabile vel non sonabile); albedo et nigredo, quae pertinent ad visum; dulcedo et amaritudo, quae pertinent ad gustum; humiditas et siccitas, densitas et raritas, quae pertinent ad tactum. Et eadem ratio est de his contrariis, et de mediis horum. Et similiter etiam sunt alia quae sub sensu cadunt, sicut calor et frigus, et lenitas et asperitas, quae etiam tactu comprehenduntur. Huiusmodi enim sunt quaedam passiones sub genere qualitatis contentae: et dicuntur passiones, quia passionem ingerunt sensibus, vel quia ab aliquibus passionibus causantur, ut in praedicamentis dicitur. Dicuntur autem passiones sensibilium corporum, quia sensibilia corpora secundum huiusmodi differunt; inquantum scilicet unum est calidum et aliud frigidum, unum grave et aliud leve, et sic de aliis; aut inquantum aliquod unum de praemissis inest duobus secundum magis et minus. Ignis enim differt ab aqua secundum differentiam calidi et frigidi; ab aere vero secundum magis et minus calidum. Et etiam secundum hoc attenditur sensibilium corporum differentia, inquantum patiuntur aliquod horum, licet non insit eis naturaliter; sicut dicimus differre calefacta ab infrigidatis, et ea quae fiunt dulcia ab his quae fiunt amara, per aliquam passionem, et non ex natura. Alterari autem secundum huiusmodi qualitates, est omnium corporum sensibilium, tam animatorum quam inanimatorum. Et quia in corporibus animatis quaedam partes sunt animatae, idest sensitivae, ut oculus et manus, quaedam autem inanimatae, idest non sensitivae, ut capilli et ossa; utraeque partes secundum huiusmodi qualitates alterantur, quia sensus sentiendo patiuntur: actiones enim sensuum, ut auditio et visio, sunt quidam motus per corpus cum aliqua sensus passione. Non enim sensus habent aliquam actionem, nisi per organum corporeum: corpori autem convenit moveri et alterari. Unde passio et alteratio magis proprie dicitur in sensu quam in intellectu, cuius operatio non est per aliquod organum corporeum. Sic igitur patet quod secundum quascumque qualitates, et secundum quoscumque motus, alterantur corpora inanimata, secundum eosdem motus et easdem qualitates alterantur corpora animata. Sed non convertitur; quia in corporibus animatis invenitur alteratio secundum sensum, quae non invenitur in corporibus inanimatis. Non enim corpora inanimata cognoscunt suam alterationem, sed latet ea; quod non accideret, si secundum sensum alterarentur. Et ne aliquis hoc reputaret impossibile, quod aliquid alteraretur secundum sensibilem qualitatem absque sensu alterationis, subiungit quod non solum hoc est verum in rebus inanimatis, sed hoc contingit etiam in rebus animatis. Nihil enim prohibet quod etiam animata corpora lateat cum alterantur; sicut cum aliqua alteratio accidit in ipsis absque alteratione sensus, sicut cum alterantur secundum partes non sensitivas. Ex hoc igitur patet, quod si passiones sensus sunt tales, quod nihil est medium inter agens et patiens; et omnis alteratio est per huiusmodi passiones quibus alterantur sensus, sequitur quod alterans inferens passiones et alteratum patiens sint simul, et nullum sit ipsorum medium.	910. Secondly, at (694 244 b3) he proves the same thing by an argument, which is this: Every alteration is similar to an alteration which affects a sense. But in an alteration which affects a sense the cause of the alteration and the thing altered are together. Therefore, the same is true in every alteration. To prove the major premis, he says that every alteration takes place according to a sensible quality, which is the third species of quality. For bodies are apt to be altered in respect of those qualities by which bodies are primarily distinguished one from the other, i.e. in sensible qualities, such as heaviness, lightness, hardness and softness, which are perceived by touch, sound and non-sound, which are perceived by hearing. (However, if sound is considered in act, it is a quality of the air, resulting from a local motion; consequently, it does not seem that there can be a primary and per se alteration according to a quality of this sort. But if sound is taken in an aptitudinal sense, then it is through some alteration that something becomes soundable or non-soundable.) There are also blackness and whiteness, which pertain to sight; sweetness and bitterness, which pertain to taste; dryness and wetness, density and rarity, which pertain to touch. The same goes for the contraries of these and for the intermediates. Likewise, there are others which are perceptible by sense, such as cold and heat, smoothness and roughness, which are apprehended by touch. All these are passions contained within the genus of quality. And they are called “passions” because they produce a passion in the sense (i.e., the senses come to be in the state of being acted upon) or because they are caused by certain passions, as is explained in the Predicaments. But they are called “passions of sensible bodies” because it is in respect of these that sensible bodies differ, inasmuch as one is hot and another cold, one is heavy and another light, and so on, or inasmuch as someone of them is present in two things, more so in one thing and less so in another. Fire, for example, differs from water by reason of the difference of hot and cold, and from air according to more and. less hot. Again, the difference of sensible bodies is based on the ability of some of them to receive one or the other of these qualities, although it not be in them naturally; for example, we say that heated objects differ from cooled objects and sweetened things from things made bitter, not because they are so by nature, but because they have been acted upon by these qualities. The capacity to be altered in respect of qualities of these kinds is common to all sensible bodies both living and non-living. And some parts of living bodies are animate, i.e., capable of sensing, as the eye and the hand, and some parts inanimate, i.e., incapable of sensing, as the hair and bones, yet in either case all these parts are altered by qualities of this sort, because even the senses in sensing are acted upon. For the acts of the senses, such as hearing and seeing, are motions through the body and involve the sense being acted upon. For the senses have no action independent of a bodily organ, which is a body that is apt to be moved and altered. Hence passion and alteration are more properly spoken of in regard to the senses than to the intellect, whose operation does not take place through a bodily organ. Thus it is evident that according to whatever qualities and according to whatever ways inanimate bodies are altered, animate bodies are altered according to the same qualities and in the same ways. But not vice versa: for an alteration is found in animate bodies that is not found in inanimate bodies, i.e., the one according to sense. For inanimate bodies do not perceive the alterations they undergo—something that would not be, if they were altered in respect of sense. Lest anyone believe that it is impossible for something to be altered with respect to a sensible quality without a sensation of the alteration, he adds that this is true not only in inanimate things but also in the animate. For there is nothing to prevent living bodies from not perceiving that they are being affected by a quality, as when something happens in them without the sense being affected; for example, when they are altered in regard to non-sensitive parts. From this, therefore, it is evident that if the passions of the senses are such that there is nothing intermediate between the agent and the patient, and if it is true that every alteration takes place through passions by which senses are apt to be altered, it follows that the cause of an alteration (when it is producing a passion) and the object acted upon are together, and there is nothing intermediate between them.
lib. 7 l. 4 n. 3 Deinde cum dicit: huic autem etc., probat secundum, quod in alteratione sensus alterans et alteratum sint simul, quia huic, scilicet sensui, puta visui, aer continuus est, idest absque medio coniunctus, aeri vero corpus visibile; et superficies quidem visibilis corporis, quae est subiectum coloris, terminatur ad lumen, idest ad aerem illuminatum, qui terminatur ad visum. Et sic patet quod aer alteratus, et alterans ipsum, sunt simul, et similiter visus alteratus cum aere alterante. Et similiter est in auditu et in odoratu, si comparentur ad id quod primum movet, scilicet ad sensibile corpus; quia hi sensus sunt per medium extrinsecum. Gustus autem et sapor sunt simul; non enim coniunguntur per aliquod medium extrinsecum: et simile est de tactu. Et eodem modo se habet in rebus inanimatis et insensibilibus, scilicet quod alterans et alteratum sunt simul.	911. Then at (695 245 a5) he proves a second point, namely, that in alterations of the senses, the altering cause and the sense affected are together, because the air is continuous with the sense, for example, of sight, i.e., they are in immediate contacts just as the visible body is in contact with the air. Indeed, the visible body’s surface, which is the subject of color, is terminated at the light, i.e., at air which is illumined, which is terminated at the sense. And so it is evident that the altered air and what alters it are together, as are the altered sight and the air which alters sight. The same is true in hearing and in smelling, if you relate them to the first mover, namely, the sensible body, for these two senses are affected by an extrinsic medium. Taste, however, and its object are together, for they are not joined by means of an extrinsic medium, and the same goes for touch. Consequently, it remains that inanimate and insensible things are related in the same way, i.e., the cause of alteration and the thing altered are together.
lib. 7 l. 4 n. 4 Deinde cum dicit: et quod augetur etc., probat idem in motu augmenti et decrementi. Et primo in motu augmenti. Oportet enim quod augetur et auget esse simul, quia augmentum est quaedam appositio: per appositionem enim alicuius quanti aliquid augetur. Et similiter est in decremento; quia causa decrementi est quaedam subtractio alicuius quanti. Et potest intelligi haec probatio dupliciter. Uno modo secundum quod ipsum quantum appositum vel subtractum, est proximum movens illis motibus: nam et Aristoteles dicit in secundo de anima, quod caro auget prout est quanta. Et sic manifeste simul cum movente motum est: non enim potest aliquid apponi vel subtrahi alicui, si non sit simul cum eo. Procedit etiam haec ratio de principali agente. Appositio enim omnis congregatio quaedam est, subtractio autem disgregatio quaedam. Supra autem ostensum est, quod in motu congregationis et disgregationis movens et motum sunt simul: unde relinquitur, quod etiam in motu augmenti et decrementi. Et sic ulterius concludit universaliter, quod inter ultimum movens et primum motum nihil est medium.	912. Then at (696 245 a10) he proves the same thing for the motion of growth and decrease. First of all in the motion of growth. For the cause of increase and the very thing that is increased must be together, because growing is a kind of “adding to,” a quantity being increased by adding to it another quantity. The same is true of decrease, because the cause of decrease is the taking away of some quantity. Now this proof can be understood in two ways. In one way, that the very quantity added or taken away is the immediate mover in these motions, for Aristotle says in On the Soul II that flesh increases because it is quantified. Thus it is clear that the mover and the moved are together, for nothing can be added or taken away from something unless it be together with it. In another way, this argument can be understood in terms of the principal agent. For adding is a type of gathering and subtracting a type of scattering. But it was proved above that in the motions of gathering and scattering, the mover and the moved are together. Hence, what remains is that even in the motion of growth and decrease, they are together. In this way, then, he concludes universally that between the last mover and the first moved there is nothing in between.