Commentaria in Summam contra Gentiles, Liber II

After Saint Thomas had determined concerning the union of the intellectual soul with the body, he now determines concerning the duration of that soul itself ¹. Concerning this he does two things: first, indeed, he determines concerning its duration after its union with the body; second, concerning its duration before the said union, in chapter LXXXIII. As to the first, he does two things: first, he treats of the duration of the intellectual soul itself; second, occasionally, concerning the duration of the souls of brute animals, in chapter lxxxii.

As to the first, he does two things: first, he shows that the intellective soul is immortal; second, against a determinate truth he brings forward objections ².

I. As to the first point, he argues that the intellective soul is not corrupted when the body is corrupted, but is immortal. First, by arguments; second, by the authorities of Aristotle ³.

First, therefore, he argues as follows. The soul is a certain intellectual substance. Therefore it is immortal: because every intellectual substance is incorruptible, as was proved above, chapter 55.

Second. The perfection of the human soul consists in a certain abstraction from the body, as is evident in the perfection that comes from knowledge and virtue: for with respect to knowledge, the soul is perfected all the more the more it considers immaterial things; and the perfection of virtue consists in this, that man not follow the passions of the body. Therefore its corruption does not consist in separation from the body. — The consequence is proved. Because no thing is corrupted by that in which its perfection consists, since changes toward perfection and changes toward corruption are contraries.

If it is said that the perfection of the soul consists in separation with respect to operation, but not in separation with respect to being, while in separation with respect to being there consists corruption — the contrary is argued. For since operation follows upon nature, the operation of a thing cannot be perfected except insofar as its substance is perfected. And thus, if the soul is perfected with respect to operation by leaving the body, its substance will not fail in its being on account of the fact that it is separated from the body.

2. Concerning this proposition, The operation of a thing cannot be perfected except insofar as its substance is perfected, a doubt arises. For, if this is so, it follows that, since the soul separated from the body is more perfect in its operation, it is also more perfect in substance. The opposite of this has been shown above, according to the mind of St. Thomas, in chapter lxviii ⁴.

It is answered that a nature can be understood to be perfected in two ways: in one way, absolutely and in itself, that is, according to its intrinsic character; in another way, as ordered to operation, inasmuch as it becomes freer and more efficacious in operating, which is a kind of perfection and accidental. The perfection of operation, therefore, sometimes follows the first perfection, but sometimes the second, inasmuch as a nature that was impeded and held back so that it could not operate in its own manner, once the impediments are removed, becomes better disposed to operate, and therefore operates more perfectly. Hence the proposition adduced is understood concerning the perfection of substance in either of those modes, not only in the first mode. And thus it is denied that the separated soul is not more perfect insofar as it is ordered to intellectual operation. For when, in accordance with what was determined in the said chapter LXVIII, it has been freed from the corruptible body impeding it, it remains freer and more efficacious for understanding. Nor was the opposite of this said above; rather, only that, when separated from the body, it is not more perfect according to its nature intrinsically and absolutely—indeed, it is less perfect, as lacking the complement of its species.

III. Third. The proper perfection of man with respect to the soul is something incorruptible. Therefore the soul too is incorruptible. The antecedent is proved: because understanding, which is man's proper operation, is of universals and incorruptibles, which are perfections of the soul. The consequence is also proved: because perfections must be proportionate to what is perfectible. This argument was expounded above, chapter 55 ⁵.

Fourth. Man naturally desires to remain in being forever, because he apprehends esse through the intellect not only as present now, but simply. Therefore the soul, by which he apprehends esse simply and at all times, is everlasting. — This argument I also explained above, in the place previously cited, ⁶ Its interpretation should therefore be sought there.

Fifth. The forms of things are received in the possible intellect insofar as they are incorruptible. Therefore the possible intellect is incorruptible. Therefore also the soul, of which the possible intellect is something. — The antecedent is proved: because they are received in the intellect insofar as they are actually intelligible. But they have this insofar as they are immaterial and universal, and consequently incorruptible. — The consequence is also proved: because each thing is received in something according to the mode of that in which it is.

Note that this argument, although it agrees with the third in its reasoning, is nevertheless distinct from it, and assumes a different middle term. For there incorruptibility is taken as the middle term absolutely and intelligibly; here, however, what is taken as the middle term is not incorruptibility itself absolutely, but the necessity of its incorruptibility from the fact that it is received in the intellect—which is a sign of the incorruptibility of the intellect.

III. Sixth. The first subject of reception among sensible things, namely prime matter, is incorruptible in its substance. Therefore much more so is the possible intellect, which is receptive of intelligible forms. Therefore the soul. — The first inference is proved: because intelligible esse is more permanent than sensible esse.

2. But it seems that this comparison is not fitting, because it is made between things of different genera. For substantial sensible esse is compared with accidental intelligible esse: for matter is the first recipient of substantial sensible esse, and the intellect is the first recipient of accidental intelligible esse. The comparison would have been fitting if the intellect had been compared with sense, because, just as the intellect is receptive of accidental intelligible esse, so sense is receptive of accidental sensible esse. But then it is false that the first recipient of accidental and abstract sensible esse is incorruptible.

It also seems false that the intelligible esse, which is received in the possible intellect, is more permanent than the sensible esse, which is received in matter, since the former is substantial and the latter accidental.

3. To the first of these it is answered that the comparison is not made between the intelligible accidental and the sensible substantial, but between the intelligible and the sensible taken absolutely and formally, abstracting from the substantial and the accidental. For in this way the possible intellect is the first receptive subject of intelligible form, namely of form that is receivable in another insofar as it is intelligible: for the intellective soul, not as it is intellective, is not receivable in matter dependent on matter; rather, as such, it exceeds the capacity of matter; but it is receivable in matter as it is a sensible form in some way. Now prime matter is the first immediate recipient of sensible form. And therefore this comparison is fitting according to proportionality, which can also be found between things of different genera.

To the second, it is said first that, comparing the intelligible to the sensible absolutely and according to its proper character, as these are understood here, it is true that the intelligible is more permanent than the sensible. For the intelligible, as intelligible, abstracts from matter, and consequently from the principle of corruption: for the principle of corruption is matter. The sensible, however, insofar as it is sensible, concerns matter.

It is said second, that the intelligible form of our intellect is also more permanent than the substantial sensible form. Because the form of our intellect has no contrariety in the intellect; but the sensible form in these lower things has contrariety, whether with respect to dispositions or with respect to accidents consequent upon the form.

IV. Seventh. Intelligibles in act, insofar as they are such, are incorruptible. Therefore the agent intellect is also incorruptible. Therefore the soul is also, whose the intellect itself is the light. — The first inference is proved. Because the maker is more honorable than what is made, as is said in III De Anima: but the agent intellect makes intelligibles.

Note what Saint Thomas says, that intelligibles as such are incorruptible in their esse. For some intelligibles, although they are material and corruptible insofar as they exist in things—on account of which they are intelligible only in potency—are nevertheless, insofar as they are actually intelligible, abstracted from matter and material conditions; and therefore in themselves they have no principle of corruption, nor do they have dependence upon it with respect to their esse. This does not befit the sensible insofar as it is sensible: for it is not abstracted from material conditions.

V. Eighth. The intellectual soul cannot be corrupted by the action of a contrary, since nothing is contrary to it; indeed, through the possible intellect it is cognizant of and receptive to contraries. Nor by the corruption of its subject, since it does not depend on the body with respect to esse, as was shown above. Nor by the deficiency of its cause, since it cannot have any cause other than an eternal one, as will be shown below. Therefore, etc. — The consequence is evident. For no form is corrupted except in one of those three ways.

It must be noted that the soul not only has no contrary with respect to its substance, as is the case with other substances, but also has no contrariety in the dispositions belonging to its esse. For there are no dispositions toward the esse of the soul, or toward its preservation, speaking absolutely: but only toward its esse in the body. And since these have a contrary, through their corruption or alteration the soul can cease to be in the body, though it cannot cease to be simply. Therefore, when Saint Thomas says that nothing is contrary to the soul, this must be understood both with respect to its substance and with respect to any dispositions that are required for its esse absolutely.

It must also be noted that when some form is said to be corrupted on account of the deficiency of a cause, this is understood of the cause of the effect not only in its coming-to-be, but also in its having been brought into being, that is, in conserving it: in which way God is the cause of the soul, and the presence of the sun is the cause of light in the air. For when the influx of such a cause fails, the effect must necessarily fail. But when the cause fails only with respect to coming-to-be, the effect already produced need not cease to be, though it does indeed cease to come to be: just as, when the house-builder fails, or the very act of building the already produced house ceases, the house need not cease to be, but only to come to be. — The other things required for the explanation of this argument, see in the place cited above ⁷.

VI. Ninth. The possible intellect is not weakened by the weakness of the body. Therefore it is incorruptible. Therefore the soul as well. — The antecedent is proved: because the intellect does not need the body. Now no power of the soul is weakened by the weakening of the body except per accidens, namely insofar as it needs a bodily organ, as is evident in the case of sight. — But the first consequence is proved: because, if the soul were corrupted by the corruption of the body, its esse would have to be weakened by its the body's weakening. And the same holds for the powers of the soul.

It must be noted that, since every form is the formal principle of being, both for the subject and for the composite, either substantially or accidentally according to the condition of the form; and consequently it has esse in its recipient: it is not weakened in its esse absolutely when the body is weakened, unless it depends on the body in such a way that it needs the body for its esse. For, if its esse does not depend on the body, nor does it need that body in order to be, there is no reason why, when the body is weakened, its esse should be weakened. For if it were weakened when the body is weakened, then the more the body were weakened, the more it too would be weakened: and thus it would follow that, when the body fails entirely, it too would fail. But because it can happen that a form which does not depend on its recipient in its esse absolutely depends on it in a qualified sense, namely with respect to its union with the body, as was said above ⁸ concerning the human soul; therefore it can be weakened, when the body is weakened, with respect to its esse united to the body. Hence also, when the body fails, it ceases to have esse united to the body, though it does not cease to be simply.

Therefore St. Thomas speaks here in the antecedent of the weakening of the soul's power simply, and not only with respect to its union with the receptive subject.

VII. As to the second point ⁹, so that it may appear that this opinion has its foundation not only in the arguments adduced, but also that it proceeded from the Prince of the Philosophers, with whom all seem to agree, Saint Thomas showed this same conclusion from his words.

But, aiming at brevity, he adduces two passages from the books of Aristotle in which he is seen most manifestly to hold that the human soul is immortal. The first is in I de Anima, text 65, where he says that the intellect seems to be a certain substance and not to be corrupted. This, as is clear from what has been said above, cannot be understood of some separate substance that would be the agent and possible intellect: for it was shown above that neither the possible intellect nor the agent intellect, according to Aristotle, is a separate substance.

The second is Metaphysics XII ¹⁰, where, after saying, at text 16, that formal causes are simultaneous with those of which they are causes, but not prior to them, he adds, at text 17: But if something posterior also remains, it must be investigated. For in some cases nothing prevents this: as if there is such a soul, not every soul, but intellect.

From these, two things are held. The first is that the intellect, which is the form of man, remains after the body: for we are speaking of forms. — The second is that it excludes the soul from the generality of all forms, positing that it itself remains after the body and is a certain substance: and it does not posit it as non-subsistent, and consequently corruptible, as Gregory of Nyssa imputes to it.

Note, as is said in De Spiritu Creaturis, article 2, that Gregory of Nyssa, in his book On the Soul, charged Aristotle with having held that the intellective soul is not subsistent, and that it is corrupted when the body is corrupted, because he held it to be the entelechy, as it were the act and perfection, of a physical body; yet it seems contrary to the nature of a spiritual substance that it be the form of a body. But this is not true: for, as was shown above ¹¹, it is necessary to hold that some spiritual substance is the form of the human body.

VIII. But because some Thomists ¹², otherwise most learned men, departing from the doctrine of Saint Thomas (who holds here, and in Metaphysics XII, expounding text 17 ¹³; likewise Quodlibet X, q. III, a. 2 ¹⁴; similarly Physics VIII, lect. 12, that Aristotle held the human soul to be immortal), attempt to show the opposite concerning Aristotle's mind: therefore, following the most true doctrine of Saint Thomas, which contains nothing false or unlearned either in expounding Sacred Scripture, or in interpreting divine things, or in his commentaries on Aristotle; first we shall bring forward their responses to the aforementioned authorities, and shall refute them with the greatest ease; then, in the following chapter, we shall answer their arguments in accordance with the most integral doctrine of Saint Thomas.

2. Therefore they say nothing against the first authority of Aristotle; but, as may be inferred from their course of argument, I think they will say either that Aristotle spoke there dubitatively, not assertively, which can appear from the fact that he uses that word "videtur," which belongs to one doubting, not to one asserting; or that he followed the opinion of others.

To the second, they likewise respond that in this authority nothing is shown affirming itself to the point at issue. For from it is manifestly had only that he thought the intellectual soul not to be before the body; but under doubt whether it be after, he left it ¹⁵.

3. But the response to the first, as regards its first part, is agreed to be none. For from Aristotle's course of argument it is clear that he does not speak there in a doubtful manner. Nor does his use of this word videtur compel that conclusion: because sometimes videtur is taken to mean the same as apparet, that is, "it is manifest"; just as Porphyry says ¹⁶, "But it seems (videtur) that neither genus nor species is said simply"; there, as Ammonius interprets it ¹⁷, videtur is taken for apparet.

As for the second part, he certainly speaks the truth, according to the interpretation of St. Thomas ¹⁸, who inquires and holds that Aristotle proves his thesis by means of a certain opinion of the Platonists which was famous in his time, namely that every soul is incorruptible, and that all the operations of the soul, even those of the intellect itself, have determinate organs. And therefore he explains "it seems" to mean, it appears to the aforementioned Philosophers. But although Aristotle speaks according to the opinion of others, he does not nevertheless depart from their opinion as regards the immortality of the intellective soul. Hence, in order to show that indeed they agree with him on this immortality, but not on the point that the operation of the intellect has an organ and withers away through the corruption of that organ, speaking in his own person and showing toward which opinion he inclines, he adds that the intellect is perhaps something divine and impassible. Here he uses the adverb of doubt, because he had not yet determined this: what he later asserts affirmatively in the Third Book, as will appear ¹⁹.

4. There is also no response to the second. For Aristotle, after he has determined that forms do not exist before the things of which they are forms, adds that it must be investigated whether any remains after the corruption of the composite, and he determines that nothing prevents it, where the text of the Commentator has, it is not impossible ²⁰, and he adds the example of the intellective soul. For he does not, as those men suppose, reply doubtfully and under a condition. For, if he were replying under a condition, he would not have inserted the ly ut, which is a particle employed for giving an example. For he would have said: “For in some cases nothing prevents it if there is such a soul”; but not, “For in some cases nothing prevents it, as if there is such a soul.” For it is evident from the manner of speaking that he responds absolutely to the question posed, when he says, “For in some cases nothing prevents it,” or, “it is not impossible.” And since this cannot be verified except of the intellective soul, he adds an example concerning it, saying, ut, that is, “for example” (as the Commentator explains ²¹, and as the truth of the Greek expression corresponding to it has it), “if there is such a soul, not every soul, but intellect.” And the sense is: that some form can remain after the dissolution of the composite; for example, if we say that the soul remains after the dissolution of the animate thing, not indeed the whole soul, but that which is intellective. — This is also clear from the following words, that he meant the same thing, when he adds: “For perhaps every soul is impossible.” For, since he had said that in some cases nothing prevents their remaining, and had given the example of the intellective soul, when he adds that this cannot be verified of every soul, he leaves it that this is not impossible in the case of the intellective soul. — Therefore, since the determination of the question is absolute, namely, that it is not impossible for some form to remain after the corruption of the composite; and since this cannot be verified except of the intellective soul: it follows that he held that the intellective soul remains after the corruption of man, and consequently is immortal.

IX. That this was his meaning, as St. Thomas judges, can be shown from many other passages.

First, because in I De Anima, text 15 ²², he concludes that, since there are certain operations of the soul that are operations of the composite, for this reason it belongs to the natural philosopher to consider the soul, either every soul, or a soul of this kind, namely one affixed to an organ. For from these words it appears that he believed there to be some soul that is not wholly dependent on matter, but has some operation in which the body does not share. For, if he had not been of this opinion, he would not have used this disjunctive, namely that it belongs to the natural philosopher to consider the soul either every soul or a material one, that is, one affixed to the body with respect to all its powers; but he would have said absolutely that it belongs to the natural philosopher to consider every soul.

Confirmed. Because in Book I of On the Parts of Animals, chapter 1 ²³, resolving this doubt, he says that it is not the task of the natural philosopher to determine concerning every soul, for then there would be no philosophy apart from natural science. For natural philosophy would be about all things: since, because the intellect is the intellect of intelligibles, and it belongs to the same science to determine concerning things that are said relatively, natural science would also determine concerning intelligibles. But it is clear that there he speaks of soul taken properly, as appears from the context of the text. Therefore he judged that there is some soul that transcends matter, and consequently is not corrupted with the corruption of the body. — That this is most plainly evident also from another argument adduced by him in the same place: because, I say, natural science cannot contemplate any thing abstracted from matter. Therefore, according to him, the intellect is abstracted from matter, and consequently incorruptible.

X. Second, because in II De Anima, text 21 ²⁴, after inquiring concerning the other powers of the soul whether each is a part of the soul, and whether it is separable from the other powers, he adds that concerning the intellect and the speculative power nothing has yet been made manifest: but it seems to be another kind of soul, and that this alone can be separated, as the everlasting from the corruptible.

If it is answered, as the aforementioned respondents answer, that this is verified only of the agent intellect, in which what is separated as the perpetual from the corruptible, because Aristotle posited only the agent intellect to be a separate and incorruptible substance: — this is most manifestly shown to be false from Aristotle's own procedure. For when, at text 18 ²⁵, he had concluded that the soul is determined by the vegetative, the sensitive, the intellective, and motion, immediately, at text 19 ²⁶, he asks whether each of these is the soul, or a part of the soul: and if a part, whether it is separable by reason alone, or also by place. And in answering this, after he had said that concerning some of these it is not difficult to see, while others have some doubt; and had shown in which ones it is easy to see; he adds concerning those in which there is doubt, saying that concerning the intellect and the prospective power nothing is yet manifest, etc. From this procedure, however, it appears that in the words cited he speaks of the intellect which is a virtue and potency of the soul, and not of an intellect which would be a separate substance. And he speaks of the whole intellective part, which he said was separated from the others formally (to use their words), and concerning which, lest it be thought to be separated thus as an accident, which, when separated from its subject, is corrupted, he adds that it is separated as the perpetual from the corruptible. Nor does that word seem, as Philoponus says ²⁷, to belong to one doubting, but it is expounded: that is, it appears and is manifest. On account of which, so that he may show himself to speak of the intellective part which is part of the soul, distinct from the other parts, he adds concerning the other parts, saying: But the remaining parts of the soul are manifestly not separable, as some say, from these things: but that they are other, is manifest by reason.

XI. Third, because in III de Anima, text. 3 ²⁸ he says that the intellect must be impassible, namely with respect to passion properly so called; and in text. 6, he holds that the possible intellect is unmixed with the body and has no corporeal organ. Then thus: The intellect is impassible, and it is a power separated from every corporeal organ. Therefore the intellective soul is not wholly immersed in matter, as depending upon it in its esse. Therefore it is immortal. — The first consequence is proved. Because powers and immaterial virtues that have no material organ do not follow upon a form wholly immersed in matter. For it follows: If it has no virtues that transcend matter and do not need a material subject, then it is wholly immersed in matter, and in no way elevated above matter. — The second consequence is also manifest. Because if it does not depend on matter in its esse, nor is wholly immersed in it, it follows that it can exist without it. For anything can exist without that from which it does not depend in its esse.

XII. Fourth, in text 20 of the same Third Book ²⁹, speaking of the whole intellective part, he says: But the separate is that alone which truly is: and that alone is immortal and perpetual. Therefore etc.

Respondent ii answers that this is said not of the whole intellective part, but of the agent intellect alone. This is clear, they say, from the manner of speaking ³⁰. For since above ³¹ he had said that even the possible intellect is separate, he now added, "this which truly is," that is: it is abstract in its esse and substantialiter, as if he wished to say: The possible intellect is separate as a line, and has an operation without a body as a sphere does ³²; but it is not separate in that which truly is, that is, in esse. But this intellect, because it has its own operation, is separate only in that which truly is, that is, in esse.

But that this response is not in accordance with Aristotle's meaning is argued from his very manner of speaking. For when we wish to exclude a thing distinct from the subject from sharing in the predicate, we do not use an exclusive expression adverbially on the side of the predicate; rather, according to true logic, we place it on the side of the subject. For when we wish to signify that whiteness belongs to no other man according to the face than to Socrates, we do not say "Socrates is white only according to the face," for this rather signifies that Socrates is not white except in the face; but we say "Socrates alone is white of face." But Aristotle uses an exclusive expression adverbially on the side of the predicate, saying that the intellect is separate only by that which truly is: and not that this intellect alone is separate in this way. Therefore he does not intend by this proposition to exclude the possible intellect from that mode of separation by which the agent intellect is separate, as these men wrongly interpret Aristotle.

Hence this text must be understood otherwise. For since "intellect" has a twofold signification, namely the proper one, which is the power, either productive or receptive, of immaterials and universals; and the improper one, which is the cogitative power (for Aristotle calls it the passive intellect below ³³), lest anyone, from the fact that he said above absolutely and indistinctly that the intellect is separate, should think that the intellect, even taken according to its improper signification, is separate, here he makes clear that he understood himself to be speaking of the intellect only as regards its proper signification. Hence the sense is: But the intellect is separate only when the name "intellect" is taken according to its proper signification, not however when it is taken according to its improper signification. And this alone, namely the proper signification of intellect, is immortal and everlasting: not however the improper one. Which he clearly shows by adding: But the passive intellect is corruptible, that is, the cogitative power: which is called intellect improperly not only according to the interpretation of St. Thomas, but also according to Philoponus's exposition ³⁴, and according to Ammonius on I Perihermeneias ³⁵, before he comes to the exposition of Aristotle's text.

2. But it is evident that this is the true interpretation of this text, if both the text of Aristotle and the Greek manner of speaking are carefully considered. For where our text has "what truly is," the Greek text has hoper (ὅπερ), which word among the Greeks has a properly demonstrative signification. Thus Suidas says ³⁶: Τοῦτο τὸ ὅπερ τοῦ κυρίως ἐστὶ δηλωτικόν, καὶ ᾧ ἐὰν προστεθῇ, τὸ κυρίως ἐκεῖνο εἶναι σημαίνει. οἷον, ὅπερ ἄνθρωπος, ὁ κυρίως ἄνθρωπος, καὶ ὅπερ ὂν καὶ ὅπερ ἀγαθόν, τὸ κυρίως ἀγαθόν: that is, "This word hoper (ὅπερ), that is, 'what truly,' signifies properly and demonstratively; and to whatever it is added, it signifies that thing's being in the proper sense: for example, 'what truly man' signifies man properly, and 'what truly being' and 'what truly good' signify good properly." Since, therefore, the text of Aristotle has Χωρισθεὶς δ᾽ἐστὶ μόνον τοῦθ᾽ ὅπερ ἐστι, that is, "but separated is only this which truly is," or, "insofar as it truly is," the sense is that the intellect is separated only according to the proper signification of the name: but not according to its improper signification, insofar as the cogitative power is called intellect improperly and by way of likeness.

3. Therefore it is not called separate in respect of what truly is, in the sense that it is separate in its esse; but that it is separate only according to its proper signification, taken as such. [For this reason], since both the agent intellect and the possible intellect belong to the proper signification of this human intellect, it follows that Aristotle intends not only concerning the agent intellect but concerning the whole intellective part, as St. Thomas interprets most excellently. Hence just as this proposition, "Socrates is white only according to the face," where the exclusive term is placed on the side of the predicate, is equivalent to this one, "Only the face in Socrates is white," where the exclusive term is placed on the side of the subject: so this proposition, "This intellect is separate only according to its proper signification," is equivalent to this one, "Only the intellect taken properly is separate." — But these are not equivalent: "This intellect is separate only in its esse, or substantially," and "Only this intellect is separate in its esse." According to their interpretation, however, these would have to be equivalent. Therefore this interpretation is bad.

XIII. Fifth. In II de Gen. Animal., chapter III ³⁷, he says that the intellect is not educed from the potency of matter, but comes from without. Therefore it is not corrupted upon the corruption of the body: for only those forms are corruptible which are educed from the potency of matter.

To this those respond who hold, as was said above, that Aristotle believed the mind to come from without, because the intellectual light by which the possible intellect is able proximately to understand and has the character of mind comes from the agent intellect ³⁸.

But that this response is not in accord with Aristotle's mind is shown as follows. For there the Philosopher inquires about the soul of the thing conceived, whence it comes and whether it is in the seed; and he explains his purpose by asking about the sensitive soul, by which the thing conceived is itself an animal, and about the rational soul, by which it is a man; and he adds that concerning the mind—by what time, and how, and whence those who share in that principle receive it—there is very great doubt. Answering this question, he says that in the things conceived and in the seeds these souls are had first in potency than in act, and that it is impossible that the others come from without, but that the mind alone comes from without, and that it alone is divine, because no bodily action shares anything with its action. Behold how openly Aristotle shows that he did not understand this of the light received from the agent intellect, but of the very substance of the soul, by which the thing conceived is constituted in the human species. Hence that response is most alien to the mind of Aristotle.

XIV. Finally, it is argued from the foundation laid by Aristotle himself in De Anima I, text 13 ³⁹. The intellective soul has its own operation, namely one in which the body does not share. Therefore it is separable from the body and immortal. — The antecedent is proved: a power that is not affixed to a bodily organ has an operation without the body as an instrument. But the intellect is of this kind, as is clear from De Anima II, text 11 ⁴⁰. Therefore, etc. — The consequence too is proved from that same foundation in De Anima I, where he says that if there is any proper work or passion of the soul, it will be possible for it to be separated; which words all the expositors understand concerning separation from the body with respect to esse.

XV. To the antecedent of this argument, those mentioned above respond ⁴¹ that what is proper to the soul can be understood in two ways. In one way, as distinguished against what is common to it and to the body organically: and then that operation is said to be proper to the soul which is performed without a bodily organ. In another way, as distinguished against what is common to it and to the body objectively: and then that operation is said to be proper to the soul which does not need the body as its object.

They say, therefore, that if "proper" is taken in the antecedent in the first way, the antecedent is indeed true, but the consequence is denied. And in reply to the proof, it is said that the Philosopher's proposition is not to the point: for in that conditional the Philosopher does not take "proper" in that way. — But if "proper" is taken in the antecedent in the second way, as the Philosopher also takes it in that conditional, then the antecedent is false: because according to Aristotle, in III de Anima, text. 30 ⁴², the soul understands nothing without a phantasm, which is the object of the intellect; but a phantasm requires a body.

This response, however, they confirm on the grounds that Aristotle posits that, if understanding is phantasia, or not without phantasia, it does not occur without the body ⁴³. For from this conditional it is gathered how the proper is taken so as to exclude the object: because he says that, if it is not without phantasia—which is, namely, as it were the object—it will not be without the body; and consequently it will not be proper to the soul. Accordingly, to this they say that Aristotle laid down this conditional in order to declare how he took what is proper to the soul: namely, that he takes it as excluding the body as object. Otherwise such a proposition, and one of such weight, would have been alleged to no purpose.

2. It can also be answered from Scotus, IV Sent., d. XLIII, q. II ⁴⁴, by denying the antecedent; and to the proof, the major premise may be denied. For it is possible that a power is not fixed to a bodily organ or bodily part, and yet is the first reason of operating for the whole. And then the operation will not take place through a bodily organ as medium: and yet it will be common to soul and body.

XVI. But that the first response is not Aristotle's meaning is shown. For Aristotle takes "proper" in the way it is opposed to "common" as posed in the question: since they are posed in the question as opposites. But the common is taken as what belongs to the soul and the organ. Therefore the proper of the soul is taken as what belongs to the soul without an organ, not as what belongs to the soul without a bodily object. — The minor is proved from Aristotle's own text, both according to our translation and according to the Greek text itself, to which it is best suited. For thus the Greek text says: Ἀπορίαν δὲ ἔχει καὶ τὰ πάθη τῆς ψυχῆς, πότερόν ἐστι πάντα κοινὰ καὶ τοῦ ἔχοντος, ἢ ἔστί τι καὶ τῆς ψυχῆς ἴδιον αὐτῆς, that is, according to our interpreter: "The passions of the soul also present a difficulty: whether they are all common to it and to that which has it, or whether there is something proper to the soul itself" ⁴⁵. The Philosopher therefore takes the passion of the soul that is common as belonging both to the soul itself and to that which has it. But by the name "that which has it" he certainly understands the organic body to which the power of the soul is affixed, because that body has the power, not the object. Therefore there too he takes the proper of the soul as what belongs to the soul alone, not to it and to that which has it, that is, the organ. Therefore he does not take "proper" as excluding the body objectively, but as excluding the body organically and instrumentally. Therefore, when in text 13, from the doubt raised he derives that conditional, "If, then, there is something proper to the soul among its operations or passions, it will assuredly be possible for it to be separated," the proper of the soul is taken as excluding the organic body, not as excluding the object body, as the response says.

But neither does the confirmation of that response carry weight. For it is said, according to the interpretation of St. Thomas, at the end of his exposition of that text 12 ⁴⁶, that Aristotle did not propose that conditional—namely, "But if this is a kind of phantasm, or not without a phantasm, it will by no means be the case that it is without the body"—as true and in accordance with his own opinion, but as merely apparent. For when he had proposed the said question, he showed the cause of its difficulty: namely, that very many passions of the soul seem to suffer or act not without the body; and that understanding most closely resembles what is proper to the soul, and yet is not itself proper to it—that is, according to appearance—if it either is a phantasm or is not without a phantasm. For if esse itself were a phantasm, as Plato wished, it would certainly demonstrate that it requires a bodily instrument, just as phantasms do. Likewise also, its not being without a phantasm, and consequently not being without a corporeal object, would lead to the apparent suspicion that it was not without a corporeal organ: because it seems to belong to a material power alone to be borne toward bodies. This, however, although it has a certain appearance, is nevertheless not true: because both a power that is not affixed to a corporeal organ, and its operation, can terminate in material things, insofar as immaterial things are made through the agent intellect. — From these things it is also evident that Aristotle did not posit that conditional superfluously: since he posited it in order to show the appearance there was concerning understanding, that it was not proper to the soul, and thus he showed the difficulty of the question.

XVII. That the second response ⁴⁷, which is taken from Scotus, does not accord with the mind of Aristotle is shown as follows. For Aristotle posits the intellect as separate from a bodily organ and from a bodily part for no other reason than that an organ is of a determinate sensible nature and mixture, on account of which the intellect would have some determinate sensible nature, and thus would be impeded from knowing all sensible natures: just as, if either the visual power or the pupil had some determinate color, it would be impeded from perceiving other colors. For in Book III of De Anima, text 6 ⁴⁸, he says: Hence it is not reasonable that it be mingled with the body. For it would become of a certain quality, either hot or cold, if it were to have an organ, as the sensitive power does. But the same thing would happen if the intellect were posited to inform the whole body, or to be its first principle of operating, so that understanding would belong to the composite of intellect and whole body: since the whole body is no less mixed than a part, nor does it have less a determinate sensible nature. Therefore the intellect, and the operation of understanding, are no less separate from the whole body than from a part of the body. If, then, it is true that it has an operation proper to itself which no bodily organ shares, it will also be true that it has an operation proper to itself which not even the whole body itself shares.

Finally, Saint Thomas confirms his conclusion by the authority of the book On Ecclesiastical Dogmas. And he adds that by this means the error of the impious is excluded, in whose person Wisdom 2 and Ecclesiastes 3 say that the soul is corruptible.