Respondeo dicendum quod Plato posuit diversas animas esse in corpore uno, etiam secundum organa distinctas, quibus diversa opera vitae attribuebat; dicens vim nutritivam esse in hepate, concupiscibilem in corde, cognoscitivam in cerebro. Quam quidem opinionem Aristoteles reprobat, in libro de Anima, quantum ad illas animae partes quae corporeis organis in suis operibus utuntur, ex hoc quod in animalibus quae decisa vivunt, in qualibet parte inveniuntur diversae operationes animae, sicut sensus et appetitus. Hoc autem non esset, si diversa principia operationum animae, tanquam per essentiam diversae, diversis partibus corporis distributa essent. Sed de intellectiva sub dubio videtur relinquere utrum sit separata ab aliis partibus animae solum ratione, an etiam loco. I answer that, Plato held that there were several souls in one body, distinct even as to organs, to which souls he referred the different vital actions, saying that the nutritive power is in the liver, the concupiscible in the heart, and the power of knowledge in the brain. Which opinion is rejected by Aristotle (De Anima ii, 2), with regard to those parts of the soul which use corporeal organs; for this reason, that in those animals which continue to live when they have been divided, in each part are observed the operations of the soul, as sense and appetite. Now this would not be the case if the various principles of the soul’s operations were essentially different, and distributed in the various parts of the body. But with regard to the intellectual part, he seems to leave it in doubt whether it be only logically distinct from the other parts of the soul, or also locally. Opinio autem Platonis sustineri utique posset, si poneretur quod anima unitur corpori, non ut forma, sed ut motor, ut posuit Plato. Nihil enim inconveniens sequitur, si idem mobile a diversis motoribus moveatur, praecipue secundum diversas partes. Sed si ponamus animam corpori uniri sicut formam, omnino impossibile videtur plures animas per essentiam differentes in uno corpore esse. Quod quidem triplici ratione manifestari potest. The opinion of Plato might be maintained if, as he held, the soul was supposed to be united to the body, not as its form, but as its motor. For it involves nothing unreasonable that the same movable thing be moved by several motors; and still less if it be moved according to its various parts. If we suppose, however, that the soul is united to the body as its form, it is quite impossible for several essentially different souls to be in one body. This can be made clear by three different reasons. Primo quidem, quia animal non esset simpliciter unum, cuius essent animae plures. Nihil enim est simpliciter unum nisi per formam unam, per quam habet res esse, ab eodem enim habet res quod sit ens et quod sit una; et ideo ea quae denominantur a diversis formis, non sunt unum simpliciter, sicut homo albus. Si igitur homo ab alia forma haberet quod sit vivum, scilicet ab anima vegetabili; et ab alia forma quod sit animal, scilicet ab anima sensibili; et ab alia quod sit homo, scilicet ab anima rationali; sequeretur quod homo non esset unum simpliciter, sicut et Aristoteles argumentatur contra Platonem, in VIII Metaphys., quod si alia esset idea animalis, et alia bipedis, non esset unum simpliciter animal bipes. Et propter hoc, in I de Anima, contra ponentes diversas animas in corpore, inquirit quid contineat illas, idest quid faciat ex eis unum. Et non potest dici quod uniantur per corporis unitatem, quia magis anima continet corpus, et facit ipsum esse unum, quam e converso. In the first place, an animal would not be absolutely one, in which there were several souls. For nothing is absolutely one except by one form, by which a thing has existence: because a thing has from the same source both existence and unity; and therefore things which are denominated by various forms are not absolutely one; as, for instance, a white man. If, therefore, man were living by one form, the vegetative soul, and animal by another form, the sensitive soul, and man by another form, the intellectual soul, it would follow that man is not absolutely one. Thus Aristotle argues, Metaph. viii (Did. vii, 6), against Plato, that if the idea of an animal is distinct from the idea of a biped, then a biped animal is not absolutely one. For this reason, against those who hold that there are several souls in the body, he asks (De Anima i, 5), what contains them?—that is, what makes them one? It cannot be said that they are united by the one body; because rather does the soul contain the body and make it one, than the reverse. Secundo, hoc apparet impossibile ex modo praedicationis. Quae enim sumuntur a diversis formis, praedicantur ad invicem vel per accidens, si formae non sint ad invicem ordinatae, puta cum dicimus quod album est dulce, vel, si formae sint ordinatae ad invicem, erit praedicatio per se, in secundo modo dicendi per se, quia subiectum ponitur in definitione praedicati. Sicut superficies praeambula est ad colorem, si ergo dicamus quod corpus superficiatum est coloratum, erit secundus modus praedicationis per se. Si ergo alia forma sit a qua aliquid dicitur animal, et a qua aliquid dicitur homo, sequeretur quod vel unum horum non possit praedicari de altero nisi per accidens, si istae duae formae ad invicem ordinem non habent; vel quod sit ibi praedicatio in secundo modo dicendi per se, si una animarum sit ad aliam praeambula. Utrumque autem horum est manifeste falsum, quia animal per se de homine praedicatur, non per accidens; homo autem non ponitur in definitione animalis, sed e converso. Ergo oportet eandem formam esse per quam aliquid est animal, et per quam aliquid est homo, alioquin homo non vere esset id quod est animal, ut sic animal per se de homine praedicetur. Second, this is proved to be impossible by the manner in which one thing is predicated of another. Those things which are derived from various forms are predicated of one another, either accidentally, (if the forms are not ordered to one another, as when we say that something white is sweet), or essentially, in the second manner of essential predication, (if the forms are ordered one to another, the subject belonging to the definition of the predicate; as a surface is presupposed to color; so that if we say that a body with a surface is colored, we have the second manner of essential predication.) Therefore, if we have one form by which a thing is an animal, and another form by which it is a man, it follows either that one of these two things could not be predicated of the other, except accidentally, supposing these two forms not to be ordered to one another—or that one would be predicated of the other according to the second manner of essential predication, if one soul be presupposed to the other. But both of these consequences are clearly false: because animal is predicated of man essentially and not accidentally; and man is not part of the definition of an animal, but the other way about. Therefore of necessity by the same form a thing is animal and man; otherwise man would not really be the thing which is an animal, so that animal can be essentially predicated of man. Tertio, apparet hoc esse impossibile per hoc, quod una operatio animae, cum fuerit intensa, impedit aliam. Quod nullo modo contingeret, nisi principium actionum esset per essentiam unum. Third, this is shown to be impossible by the fact that when one operation of the soul is intense it impedes another, which could never be the case unless the principle of action were essentially one. Sic ergo dicendum quod eadem numero est anima in homine sensitiva et intellectiva et nutritiva. Quomodo autem hoc contingat, de facili considerari potest, si quis differentias specierum et formarum attendat. Inveniuntur enim rerum species et formae differre ab invicem secundum perfectius et minus perfectum, sicut in rerum ordine animata perfectiora sunt inanimatis, et animalia plantis, et homines animalibus brutis, et in singulis horum generum sunt gradus diversi. Et ideo Aristoteles, in VIII Metaphys., assimilat species rerum numeris, qui differunt specie secundum additionem vel subtractionem unitatis. Et in II de Anima, comparat diversas animas speciebus figurarum, quarum una continet aliam; sicut pentagonum continet tetragonum, et excedit. Sic igitur anima intellectiva continet in sua virtute quidquid habet anima sensitiva brutorum, et nutritiva plantarum. Sicut ergo superficies quae habet figuram pentagonam, non per aliam figuram est tetragona, et per aliam pentagona; quia superflueret figura tetragona, ex quo in pentagona continetur; ita nec per aliam animam Socrates est homo, et per aliam animal, sed per unam et eandem. We must therefore conclude that in man the sensitive soul, the intellectual soul, and the nutritive soul are numerically one soul. This can easily be explained, if we consider the differences of species and forms. For we observe that the species and forms of things differ from one another, as the perfect and imperfect; as in the order of things, the animate are more perfect than the inanimate, and animals more perfect than plants, and man than brute animals; and in each of these genera there are various degrees. For this reason Aristotle, Metaph. viii (Did. vii, 3), compares the species of things to numbers, which differ in species by the addition or subtraction of unity. And (De Anima ii, 3) he compares the various souls to the species of figures, one of which contains another; as a pentagon contains and exceeds a tetragon. Thus the intellectual soul contains virtually whatever belongs to the sensitive soul of brute animals, and to the nutritive souls of plants. Therefore, as a surface which is of a pentagonal shape, is not tetragonal by one shape, and pentagonal by another—since a tetragonal shape would be superfluous as contained in the pentagonal—so neither is Socrates a man by one soul, and animal by another; but by one and the same soul he is both animal and man. Ad primum ergo dicendum quod anima sensitiva non habet incorruptibilitatem ex hoc quod est sensitiva, sed ex hoc quod est intellectiva, ei incorruptibilitas debetur. Quando ergo anima est sensitiva tantum, corruptibilis est, quando vero cum sensitivo intellectivum habet, est incorruptibilis. Licet enim sensitivum incorruptionem non det, tamen incorruptionem intellectivo auferre non potest. Reply Obj. 1: The sensitive soul is incorruptible, not by reason of its being sensitive, but by reason of its being intellectual. When, therefore, a soul is sensitive only, it is corruptible; but when with sensibility it has also intellectuality, it is incorruptible. For although sensibility does not give incorruptibility, yet it cannot deprive intellectuality of its incorruptibility. Ad secundum dicendum quod formae non collocantur in genere vel in specie, sed composita. Homo autem corruptibilis est, sicut et alia animalia. Unde differentia secundum corruptibile et incorruptibile, quae est ex parte formarum, non facit hominem secundum genus ab aliis animalibus differre. Reply Obj. 2: Not forms, but composites, are classified either generically or specifically. Now man is corruptible like other animals. And so the difference of corruptible and incorruptible which is on the part of the forms does not involve a generic difference between man and the other animals. Ad tertium dicendum quod prius embryo habet animam quae est sensitiva tantum; qua abiecta, advenit perfectior anima, quae est simul sensitiva et intellectiva; ut infra plenius ostendetur. Reply Obj. 3: The embryo has first of all a soul which is merely sensitive, and when this is removed, it is supplanted by a more perfect soul, which is both sensitive and intellectual: as will be shown further on (Q. 118, A. 2, ad 2). Ad quartum dicendum quod non oportet secundum diversas rationes vel intentiones logicas, quae consequuntur modum intelligendi, diversitatem in rebus naturalibus accipere, quia ratio unum et idem secundum diversos modos apprehendere potest. Quia igitur, ut dictum est, anima intellectiva virtute continet id quod sensitiva habet, et adhuc amplius; potest seorsum ratio considerare quod pertinet ad virtutem sensitivae, quasi quoddam imperfectum et materiale. Et quia hoc invenit commune homini et aliis animalibus, ex hoc rationem generis format. Id vero in quo anima intellectiva sensitivam excedit, accipit quasi formale et completivum, et ex eo format differentiam hominis. Reply Obj. 4: We must not consider the diversity of natural things as proceeding from the various logical notions or intentions, which flow from our manner of understanding, because reason can apprehend one and the same thing in various ways. Therefore since, as we have said, the intellectual soul contains virtually what belongs to the sensitive soul, and something more, reason can consider separately what belongs to the power of the sensitive soul, as something imperfect and material. And because it observes that this is something common to man and to other animals, it forms thence the notion of the genus; while that wherein the intellectual soul exceeds the sensitive soul, it takes as formal and perfecting; thence it gathers the difference of man. Articulus 4 Article 4 Utrum in homine sit alia forma praeter animam intellectivam Whether in man there is another form besides the intellectual soul? Ad quartum sic proceditur. Videtur quod in homine sit alia forma praeter animam intellectivam. Dicit enim Philosophus, in II de Anima, quod anima est actus corporis physici potentia vitam habentis. Comparatur igitur anima ad corpus, sicut forma ad materiam. Sed corpus habet aliquam formam substantialem per quam est corpus. Ergo ante animam praecedit in corpore aliqua forma substantialis. Objection 1: It would seem that in man there is another form besides the intellectual soul. For the Philosopher says (De Anima ii, 1), that the soul is the act of a physical body which has life potentially. Therefore the soul is to the body as a form of matter. But the body has a substantial form by which it is a body. Therefore some other substantial form in the body precedes the soul. Praeterea, homo et quodlibet animal est movens seipsum. Omne autem movens seipsum dividitur in duas partes, quarum una est movens, et alia est mota, ut probatur in VIII Physic. Pars autem movens est anima. Ergo oportet quod alia pars sit talis quae possit esse mota. Sed materia prima non potest moveri, ut dicitur in V Physic., cum sit ens solum in potentia, quinimmo omne quod movetur est corpus. Ergo oportet quod in homine et in quolibet animali sit alia forma substantialis, per quam constituatur corpus. Obj. 2: Further, man moves himself as every animal does. Now everything that moves itself is divided into two parts, of which one moves, and the other is moved, as the Philosopher proves (Phys. viii, 5). But the part which moves is the soul. Therefore the other part must be such that it can be moved. But primary matter cannot be moved (Phys. v, 1), since it is a being only potentially; indeed everything that is moved is a body. Therefore in man and in every animal there must be another substantial form, by which the body is constituted. Praeterea, ordo in formis attenditur secundum habitudinem ad materiam primam, prius enim et posterius dicitur per comparationem ad aliquod principium. Si ergo non esset in homine alia forma substantialis praeter animam rationalem, sed immediate materiae primae inhaereret; sequeretur quod esset in ordine imperfectissimarum formarum, quae immediate inhaerent materiae. Obj. 3: Further, the order of forms depends on their relation to primary matter; for before and after apply by comparison to some beginning. Therefore if there were not in man some other substantial form besides the rational soul, and if this were to inhere immediately to primary matter; it would follow that it ranks among the most imperfect forms which inhere to matter immediately. Praeterea, corpus humanum est corpus mixtum. Mixtio autem non fit secundum materiam tantum, quia tunc esset corruptio sola. Oportet ergo quod remaneant formae elementorum in corpore mixto, quae sunt formae substantiales. Ergo in corpore humano sunt aliae formae substantiales praeter animam intellectivam. Obj. 4: Further, the human body is a mixed body. Now mingling does not result from matter alone; for then we should have mere corruption. Therefore the forms of the elements must remain in a mixed body; and these are substantial forms. Therefore in the human body there are other substantial forms besides the intellectual soul. Sed contra, unius rei est unum esse substantiale. Sed forma substantialis dat esse substantiale. Ergo unius rei est una tantum forma substantialis. Anima autem est forma substantialis hominis. Ergo impossibile est quod in homine sit aliqua alia forma substantialis quam anima intellectiva. On the contrary, Of one thing there is but one substantial being. But the substantial form gives substantial being. Therefore of one thing there is but one substantial form. But the soul is the substantial form of man. Therefore it is impossible for there to be in man another substantial form besides the intellectual soul. Respondeo dicendum quod, si poneretur anima intellectiva non uniri corpori ut forma, sed solum ut motor, ut Platonici posuerunt; necesse esset dicere quod in homine esset alia forma substantialis, per quam corpus ab anima mobile in suo esse constitueretur. Sed si anima intellectiva unitur corpori ut forma substantialis, sicut supra iam diximus, impossibile est quod aliqua alia forma substantialis praeter eam inveniatur in homine. I answer that, If we suppose that the intellectual soul is not united to the body as its form, but only as its motor, as the Platonists maintain, it would necessarily follow that in man there is another substantial form, by which the body is established in its being as movable by the soul. If, however, the intellectual soul be united to the body as its substantial form, as we have said above (A. 1), it is impossible for another substantial form besides the intellectual soul to be found in man. Ad cuius evidentiam, considerandum est quod forma substantialis in hoc a forma accidentali differt, quia forma accidentalis non dat esse simpliciter, sed esse tale, sicut calor facit suum subiectum non simpliciter esse, sed esse calidum. Et ideo cum advenit forma accidentalis, non dicitur aliquid fieri vel generari simpliciter, sed fieri tale aut aliquo modo se habens, et similiter cum recedit forma accidentalis, non dicitur aliquid corrumpi simpliciter, sed secundum quid. Forma autem substantialis dat esse simpliciter, et ideo per eius adventum dicitur aliquid simpliciter generari, et per eius recessum simpliciter corrumpi. Et propter hoc antiqui naturales, qui posuerunt materiam primam esse aliquod ens actu, puta ignem aut aerem aut aliquid huiusmodi, dixerunt quod nihil generatur aut corrumpitur simpliciter, sed omne fieri statuerunt alterari, ut dicitur in I Physic. Si igitur ita esset, quod praeter animam intellectivam praeexisteret quaecumque alia forma substantialis in materia, per quam subiectum animae esset ens actu; sequeretur quod anima non daret esse simpliciter; et per consequens quod non esset forma substantialis; et quod per adventum animae non esset generatio simpliciter, neque per eius abscessum corruptio simpliciter, sed solum secundum quid. Quae sunt manifeste falsa. In order to make this evident, we must consider that the substantial form differs from the accidental form in this, that the accidental form does not make a thing to be simply, but to be such, as heat does not make a thing to be simply, but only to be hot. Therefore by the coming of the accidental form a thing is not said to be made or generated simply, but to be made such, or to be in some particular condition; and in like manner, when an accidental form is removed, a thing is said to be corrupted, not simply, but relatively. Now the substantial form gives being simply; therefore by its coming a thing is said to be generated simply; and by its removal to be corrupted simply. For this reason, the old natural philosophers, who held that primary matter was some actual being—for instance, fire or air, or something of that sort—maintained that nothing is generated simply, or corrupted simply; and stated that every becoming is nothing but an alteration, as we read, Phys. i, 4. Therefore, if besides the intellectual soul there pre-existed in matter another substantial form by which the subject of the soul were made an actual being, it would follow that the soul does not give being simply; and consequently that it is not the substantial form: and so at the advent of the soul there would not be simple generation; nor at its removal simple corruption, all of which is clearly false. Unde dicendum est quod nulla alia forma substantialis est in homine, nisi sola anima intellectiva; et quod ipsa, sicut virtute continet animam sensitivam et nutritivam, ita virtute continet omnes inferiores formas, et facit ipsa sola quidquid imperfectiores formae in aliis faciunt. Et similiter est dicendum de Anima sensitiva in brutis, et de nutritiva in plantis, et universaliter de omnibus formis perfectioribus respectu imperfectiorum. Whence we must conclude, that there is no other substantial form in man besides the intellectual soul; and that the soul, as it virtually contains the sensitive and nutritive souls, so does it virtually contain all inferior forms, and itself alone does whatever the imperfect forms do in other things. The same is to be said of the sensitive soul in brute animals, and of the nutritive soul in plants, and universally of all more perfect forms with regard to the imperfect. Ad primum ergo dicendum quod Aristoteles non dicit animam esse actum corporis tantum, sed actum corporis physici organici potentia vitam habentis, et quod talis potentia non abiicit animam. Unde manifestum est quod in eo cuius anima dicitur actus, etiam anima includitur; eo modo loquendi quo dicitur quod calor est actus calidi, et lumen est actus lucidi; non quod seorsum sit lucidum sine luce, sed quia est lucidum per lucem. Et similiter dicitur quod anima est actus corporis etc., quia per animam et est corpus, et est organicum, et est potentia vitam habens. Sed actus primus dicitur in potentia respectu actus secundi, qui est operatio. Talis enim potentia est non abiiciens, idest non excludens, animam. Reply Obj. 1: Aristotle does not say that the soul is the act of a body only, but the act of a physical organic body which has life potentially; and that this potentiality does not reject the soul. Whence it is clear that when the soul is called the act, the soul itself is included; as when we say that heat is the act of what is hot, and light of what is lucid; not as though lucid and light were two separate things, but because a thing is made lucid by the light. In like manner, the soul is said to be the act of a body, etc., because by the soul it is a body, and is organic, and has life potentially. Yet the first act is said to be in potentiality to the second act, which is operation; for such a potentiality does not reject—that is, does not exclude—the soul. Ad secundum dicendum quod anima non movet corpus per esse suum, secundum quod unitur corpori ut forma; sed per potentiam motivam, cuius actus praesupponit iam corpus effectum in actu per animam; ut sic anima secundum vim motivam sit pars movens, et corpus animatum sit pars mota. Reply Obj. 2: The soul does not move the body by its essence, as the form of the body, but by the motive power, the act of which presupposes the body to be already actualized by the soul: so that the soul by its motive power is the part which moves; and the animate body is the part moved. Ad tertium dicendum quod in materia considerantur diversi gradus perfectionis, sicut esse, vivere, sentire, et intelligere. Semper autem secundum superveniens priori, perfectius est. Forma ergo quae dat solum primum gradum perfectionis materiae, est imperfectissima, sed forma quae dat primum et secundum, et tertium, et sic deinceps, est perfectissima; et tamen materiae immediata. Reply Obj. 3: We observe in matter various degrees of perfection, as existence, living, sensing, and understanding. Now what is added is always more perfect. Therefore that form which gives matter only the first degree of perfection is the most imperfect; while that form which gives the first, second, and third degree, and so on, is the most perfect: and yet it inheres to matter immediately. Ad quartum dicendum quod Avicenna posuit formas substantiales elementorum integras remanere in mixto, mixtionem autem fieri secundum quod contrariae qualitates elementorum reducuntur ad medium. Sed hoc est impossibile. Quia diversae formae elementorum non possunt esse nisi in diversis partibus materiae; ad quarum diversitatem oportet intelligi dimensiones, sine quibus materia divisibilis esse non potest. Materia autem dimensioni subiecta non invenitur nisi in corpore. Diversa autem corpora non possunt esse in eodem loco. Unde sequitur quod elementa sint in mixto distincta secundum situm. Et ita non erit vera mixtio, quae est secundum totum, sed mixtio ad sensum, quae est secundum minima iuxta se posita. Reply Obj. 4: Avicenna held that the substantial forms of the elements remain entire in the mixed body; and that the mixture is made by the contrary qualities of the elements being reduced to an average. But this is impossible, because the various forms of the elements must necessarily be in various parts of matter; for the distinction of which we must suppose dimensions, without which matter cannot be divisible. Now matter subject to dimension is not to be found except in a body. But various bodies cannot be in the same place. Whence it follows that elements in the mixed body would be distinct as to situation. And then there would not be a real mixture which is in respect of the whole; but only a mixture apparent to sense, by the juxtaposition of particles. Averroes autem posuit, in III de Caelo, quod formae elementorum, propter sui imperfectionem, sunt mediae inter formas accidentales et substantiales; et ideo recipiunt magis et minus; et ideo remittuntur in mixtione et ad medium reducuntur, et conflatur ex eis una forma. Sed hoc est etiam magis impossibile. Nam esse substantiale cuiuslibet rei in indivisibili consistit; et omnis additio et subtractio variat speciem, sicut in numeris, ut dicitur in VIII Metaphys. Unde impossibile est quod forma substantialis quaecumque recipiat magis et minus. Nec minus est impossibile aliquid esse medium inter substantiam et accidens. Averroes maintained that the forms of elements, by reason of their imperfection, are a medium between accidental and substantial forms, and so can be more or less; and therefore in the mixture they are modified and reduced to an average, so that one form emerges from them. But this is even still more impossible. For the substantial being of each thing consists in something indivisible, and every addition and subtraction varies the species, as in numbers, as stated in Metaph. viii (Did. vii, 3); and consequently it is impossible for any substantial form to receive more or less. Nor is it less impossible for anything to be a medium between substance and accident. Et ideo dicendum est, secundum Philosophum in I de Generat., quod formae elementorum manent in mixto non actu, sed virtute. Manent enim qualitates propriae elementorum, licet remissae, in quibus est virtus formarum elementarium. Et huiusmodi qualitas mixtionis est propria dispositio ad formam substantialem corporis mixti, puta formam lapidis, vel animae cuiuscumque. Therefore we must say, in accordance with the Philosopher (De Gener. i, 10), that the forms of the elements remain in the mixed body, not actually but virtually. For the proper qualities of the elements remain, though modified; and in them is the power of the elementary forms. This quality of the mixture is the proper disposition for the substantial form of the mixed body; for instance, the form of a stone, or of any sort of soul. Articulus 5 Article 5 Utrum anima intellectiva convenienter tali corpori uniatur Whether the intellectual soul is properly united to such a body? Ad quintum sic proceditur. Videtur quod anima intellectiva inconvenienter tali corpori uniatur. Materia enim debet esse proportionata formae. Sed anima intellectiva est forma incorruptibilis. Non ergo convenienter unitur corpori corruptibili. Objection 1: It would seem that the intellectual soul is improperly united to such a body. For matter must be proportionate to the form. But the intellectual soul is incorruptible. Therefore it is not properly united to a corruptible body. Praeterea, anima intellectiva est forma maxime immaterialis, cuius signum est, quod habet operationem in qua non communicat materia corporalis. Sed quanto corpus est subtilius, tanto minus habet de materia. Ergo anima deberet subtilissimo corpori uniri, puta igni; et non corpori mixto, et terrestri magis. Obj. 2: Further, the intellectual soul is a perfectly immaterial form; a proof whereof is its operation in which corporeal matter does not share. But the more subtle is the body, the less has it of matter. Therefore the soul should be united to a most subtle body, to fire, for instance, and not to a mixed body, still less to a terrestrial body. Praeterea, cum forma sit principium speciei, ab una forma non proveniunt diversae species. Sed anima intellectiva est una forma. Ergo non debet uniri corpori quod componitur ex partibus dissimilium specierum. Obj. 3: Further, since the form is the principle of the species, one form cannot produce a variety of species. But the intellectual soul is one form. Therefore, it should not be united to a body which is composed of parts belonging to various species. Praeterea, perfectioris formae debet esse perfectius susceptibile. Sed anima intellectiva est perfectissima animarum. Cum igitur aliorum animalium corpora habeant naturaliter insita tegumenta, puta pilorum loco vestium, et unguium loco calceamentorum; habeant etiam arma naturaliter sibi data, sicut ungues, dentes et cornua, ergo videtur quod anima intellectiva non debuerit uniri corpori imperfecto tanquam talibus auxiliis privato. Obj. 4: Further, what is susceptible of a more perfect form should itself be more perfect. But the intellectual soul is the most perfect of souls. Therefore since the bodies of other animals are naturally provided with a covering, for instance, with hair instead of clothes, and hoofs instead of shoes; and are, moreover, naturally provided with arms, as claws, teeth, and horns; it seems that the intellectual soul should not have been united to a body which is imperfect as being deprived of the above means of protection. Sed contra est quod dicit Philosophus, in II de Anima, quod anima est actus corporis physici organici potentia vitam habentis. On the contrary, The Philosopher says (De Anima ii, 1) that the soul is the act of a physical organic body having life potentially. Respondeo dicendum quod, cum forma non sit propter materiam, sed potius materia propter formam; ex forma oportet rationem accipere quare materia sit talis, et non e converso. Anima autem intellectiva, sicut supra habitum est, secundum naturae ordinem, infimum gradum in substantiis intellectualibus tenet; intantum quod non habet naturaliter sibi inditam notitiam veritatis, sicut angeli, sed oportet quod eam colligat ex rebus divisibilibus per viam sensus, ut Dionysius dicit, VII cap. de Div. Nom. Natura autem nulli deest in necessariis, unde oportuit quod anima intellectiva non solum haberet virtutem intelligendi, sed etiam virtutem sentiendi. Actio autem sensus non fit sine corporeo instrumento. Oportuit igitur animam intellectivam tali corpori uniri, quod possit esse conveniens organum sensus. I answer that, Since the form is not for the matter, but rather the matter for the form, we must gather from the form the reason why the matter is such as it is; and not conversely. Now the intellectual soul, as we have seen above (Q. 55, A. 2) in the order of nature, holds the lowest place among intellectual substances; inasmuch as it is not naturally gifted with the knowledge of truth, as the angels are; but has to gather knowledge from individual things by way of the senses, as Dionysius says (Div. Nom. vii). But nature never fails in necessary things: therefore the intellectual soul had to be endowed not only with the power of understanding, but also with the power of feeling. Now the action of the senses is not performed without a corporeal instrument. Therefore it behooved the intellectual soul to be united to a body fitted to be a convenient organ of sense. Omnes autem alii sensus fundantur supra tactum. Ad organum autem tactus requiritur quod sit medium inter contraria, quae sunt calidum et frigidum, humidum et siccum, et similia, quorum est tactus apprehensivus, sic enim est in potentia ad contraria, et potest ea sentire. Unde quanto organum tactus fuerit magis reductum ad aequalitatem complexionis, tanto perceptibilior erit tactus. Anima autem intellectiva habet completissime virtutem sensitivam, quia quod est inferioris praeexistit perfectius in superiori ut dicit Dionysius in libro de Div. Nom. Unde oportuit corpus cui unitur anima intellectiva, esse corpus mixtum, inter omnia alia magis reductum ad aequalitatem complexionis. Et propter hoc homo inter omnia animalia melioris est tactus. Et inter ipsos homines, qui sunt melioris tactus, sunt melioris intellectus. Cuius signum est, quod molles carne bene aptos mente videmus, ut dicitur in II de Anima. Now all the other senses are based on the sense of touch. But the organ of touch requires to be a medium between contraries, such as hot and cold, wet and dry, and the like, of which the sense of touch has the perception; thus it is in potentiality with regard to contraries, and is able to perceive them. Therefore the more the organ of touch is reduced to an equable complexion, the more sensitive will be the touch. But the intellectual soul has the power of sense in all its completeness; because what belongs to the inferior nature pre-exists more perfectly in the superior, as Dionysius says (Div. Nom. v). Therefore the body to which the intellectual soul is united should be a mixed body, above others reduced to the most equable complexion. For this reason among animals, man has the best sense of touch. And among men, those who have the best sense of touch have the best intelligence. A sign of which is that we observe those who are refined in body are well endowed in mind, as stated in De Anima ii, 9. Ad primum ergo dicendum quod hanc obiectionem aliquis forte vellet evadere per hoc, quod diceret corpus hominis ante peccatum incorruptibile fuisse. Sed haec responsio non videtur sufficiens, quia corpus hominis ante peccatum immortale fuit non per naturam, sed per gratiae divinae donum; alioquin immortalitas eius per peccatum sublata non esset, sicut nec immortalitas daemonis. Reply Obj. 1: Perhaps someone might attempt to answer this by saying that before sin the human body was incorruptible. This answer does not seem sufficient; because before sin the human body was immortal not by nature, but by a gift of Divine grace; otherwise its immortality would not be forfeited through sin, as neither was the immortality of the devil.