Article 2 — Whether a spiritual substance can be united to a body

Second, it is asked whether a spiritual substance can be united to a body. (Parallel texts: In II Sent., d. 1, q. 2, a. 4; d. 17, q. 2, a. 1; SCG II.56–57, 68–70; Disputed Questions on the Soul, qq. 1–2; Commentary on Aristotle’s On the Soul, bk. 2, lect. 4; bk. 3, lect. 1; ST I.76.1; On the Unity of the Intellect against the Averroists, ch. 3.)

Obj. 1: And it would seem that it cannot. For Dionysius says in the first chapter of On the Divine Names (Pseudo-Dionysius, On the Divine Names, ch. 1, para. 1 (PG 3:587B).) that incorporeal things cannot be completely grasped by corporeal things. But every form is completely grasped by matter, since it is its act. Therefore, an incorporeal spiritual substance cannot be the form of the body.

Obj. 2: According to the Philosopher in the book On Sleep and Sleeplessness, the thing to which an action belongs is the thing to which the corresponding power belongs. (Aristotle, On Sleep and Sleeplessness 1, 454a8.) But understanding is the proper activity of a spiritual substance and cannot belong to the body, because understanding does not take place through a corporeal organ, as is proved in On the Soul 3. (Aristotle, On the Soul 3.4, 429a24–27.) Therefore, an intellectual power cannot be the form of the body; therefore, neither can a spiritual substance, wherein this sort of power has its basis, be the form of the body.

Obj. 3: Furthermore, what accrues to a thing after being completed accrues to it accidentally. (Cf. Porphyry, Isagogue, ch. 5.) But a spiritual substance has within itself subsistent being. If, then, a body accrues to it, it will accrue to it accidentally. Therefore, it cannot be united to it as a substantial form. (A similar argument is found in: Aquinas, Disputed Questions on the Soul, q. 2, obj. 1.)

Obj. 4: But it was said that the soul, insofar as it is “spirit,” is self-subsistent, whereas insofar as it is “soul,” it is united as a form.

On the contrary, the soul is “spirit” by its very essence; accordingly, it is the form of the body either by its very essence or else in consequence of something added to its essence. Now if the soul is the form of the body in consequence of something added to its essence, since all that accrues to a thing over and above its own essence is accidental, it follows that the soul is united to the body by means of some accident; and thus, man is a being accidentally, which is incongruous. Therefore, the soul is united to the body through its essence, insofar as it is “spirit.”

Obj. 5: Furthermore, a form does not have being on account of matter, but matter has being on account of a form. (Cf. Averroes, Commentary on Aristotle’s Physics, bk. 2, comm. 26.; bk. 4, comm. 81; Aristotle, Physics 2.2, 194b8–9; 2.8, 199a30–32; On the Soul 2.1, 412a6–10; 412a16–22.) Hence, the soul is not united to the body that the body may be perfected, but rather the body, if the soul is a form, is united to it for the soul’s perfection. But the soul does not need the body for its own perfection, since it can exist and can understand apart from the body. Therefore, the soul is not united to the body as a form.

Obj. 6: Furthermore, the union of form and matter is natural. But a soul’s union with a body is not natural, but miraculous; for it is said in the book The Spirit and the Soul, it was completely miraculous that things so diverse and so divided could have been mutually conjoined. (The work is more commonly attributed to Alcher of Clairvaux, among others: The Spirit and the Soul (De spiritu et anima), ch. 14 (PL 40:790).) Therefore, the soul is not united to the body as a form.

Obj. 7: Furthermore, according to the Philosopher in the book On Heaven, every weakening is contrary to nature. (Aristotle, On the Heavens 2.6, 288b14.) Hence, whatever weakens a thing is not united to it naturally. But the soul is weakened through union with the body, both as far as existence is concerned, because the body weighs down the soul, as is said in the book The Spirit and the Soul, (Alcher of Clairvaux, The Spirit and the Soul, ch. 14 (PL 40:789).) and as far as activity is concerned, because the soul cannot know itself save by withdrawing itself from all corporeal connections, as the same book says. (Alcher of Clairvaux, The Spirit and the Soul, ch. 32 (PL 40:802).) Therefore, the soul’s union with the body is not natural; and so, we come to the same conclusion as before.

Obj. 8: Furthermore, the Commentator says in Metaphysics 8 (Averroes, Commentary on Aristotle’s Metaphysics, bk. 8, comm. 16.) that when that which is in potency actually comes into being, this does not take place through anything additional. But when the soul is united to the body, something extrinsic is added to the body, because the soul is created by God and is infused into the body. Therefore, the soul is not the act or the form of the body.

Obj. 9: Furthermore, a form is derived from the potentiality of matter. But a spiritual substance cannot be derived from the potentiality of corporeal matter. Therefore, a spiritual substance cannot be united to the body as a form. (A similar argument is given in: Aquinas, Disputed Questions on the Soul, q. 2, obj. 12; Aristotle, On the Generation of Animals 2.3, 736b27–28.)

Obj. 10: Furthermore, the congruity of spirit to spirit is greater than the congruity of spirit to body. But a spirit cannot be the form of another spirit. Therefore, neither can a spiritual substance be the form of the body.

Obj. 11: Furthermore, Augustine says that a soul and an angel are like in nature and unlike in function. (Augustine, On Free Will, bk. 3, ch. 11, para. 32 (CSEL 74:117; PL 32:1287).) But an angel cannot be the form of the body. Therefore, neither can the soul.

Obj. 12: Furthermore, Boethius says in his book On the Person and the Two Natures that nature is the specific difference that informs each thing. (Boethius, On the Person and the Two Natures, ch. 1 (PL 64:1342B).) But the specific difference of an angel and of a soul is the same, namely, “rational.” Therefore, the nature of both is the same, and so we come to the same conclusion as before.

Obj. 13: Furthermore, the soul is related to the whole and to the parts in the same way, because it is wholly in the whole body and wholly in every single part. (See Augustine, On the Trinity, bk. 6, ch. 6, para. 8 (PL 42:929; CCSL 50:237); On the Immortality of the Soul, ch. 16, para. 25 (PL 32:1034); Contra epistulam Manichaei, ch. 16 (PL 42:185).) But a spiritual substance, which the intellect is, is not an act of any part of the body, as is said in On the Soul 3. (Aristotle, On the Soul 2.1, 413a4–7; 3.4, 429a24–b5.) Therefore, a spiritual substance is not the form of the whole body.

Obj. 14: Furthermore, a natural form existing in the body does not act outside the body. But the soul existing in the body acts outside the body, for in the Council of Ancyra it is said of women who think they go to Diana by night, that what they think they suffer in body occurs to them in spirit, (See the Council of Ancyra in: Gratian, Decretum, in Corpus iuris canonici 1 (Leipzig: Bernhard Tauchnitz, 1879), P. 2a, C. 26, q. 5, ch. 12, para. 1, 1:1030b.) and so also their spirit acts outside the body. Therefore, a spiritual substance is not united to the body as its natural form.

Obj. 15: Furthermore, in the book Articles of Faith it is said, neither form without matter nor matter without form is a subject. (Nicholas of Amiens (ca. 1147–1200 AD), De arte seu articulis Catholicae fidei, bk. 1, ch. 4 (PL 210:599B). The work is also sometimes attributed to Alan of Lille (d. 1202 AD).) But the body is the subject of some accidents; therefore, the body is not matter without form. If, then, a spiritual substance accrues to it as form, it would follow that there will be two forms in one and the same thing, which is impossible.

Obj. 16: Furthermore, the corruptible and the incorruptible differ in genus, nor is anything said of them univocally, as the Philosopher and his Commentator make clear in Metaphysics 10. (Aristotle, Metaphysics 10.10, 1058b28–29; 1058b36–1059a1; Averroes, Commentary on Aristotle’s Metaphysics, bk. 10, comm. 26.) Therefore, the corruptible and the incorruptible differ more widely than do two contraries which are species of one genus. But Boethius says that one of two contraries does not aid the other toward actual being. (Boethius, Commentary on Aristotle’s Categories, bk. 4, “De oppositis” (PL 64:282BC).) Therefore, a spiritual substance, since it is incorruptible, does not aid the corruptible body toward actual being; and hence, is not its form, since a form gives actual being to matter.

Obj. 17: Furthermore, whatever is united to another through something which is not of its own essence is not united to it as a form. But the intellect is united to the body through the imagination, which does not belong to the substance of the intellect, as the Commentator says in On the Soul 3. (Averroes, Long Commentary on Aristotle’s On the Soul, bk. 3, comm. 5, 36.) Therefore, the spiritual substance which is the intellect is not united to the body as a form.

Obj. 18: Furthermore, every spiritual substance is intellectual. Now every intellectual substance is set apart from matter, since it is something intellectual through its freedom from matter. (See Avicenna, Metaphysics, bk. 8, ch. 6.) Therefore, no spiritual substance is a form in matter, and so it cannot be united to the body as a form.

Obj. 19: Furthermore, out of matter and form a single thing comes into being. If, then, a spiritual substance is united to the body as a form, out of the spiritual substance and the body one single thing should come into being. The intelligible forms which are received in the intellect will be received in corporeal matter; this is impossible, because forms received in corporeal matter are intelligible only in potency. Therefore, the substance is not united to the body as a form.

On the contrary, there is what Dionysius says in the fourth chapter of On the Divine Names, (Pseudo-Dionysius, On the Divine Names, ch. 4, para. 1 (PG 3:694C).) that the soul is an intellectual substance which has unfailing life. But the soul is the form of the body, as is clear from the definition of it set down in On the Soul 2. (Aristotle, On the Soul 2.1, 412a20, 412b5.) Therefore some spiritual or intellectual substance is united to the body as a form.

I answer that it must be said that the difficulty of this question arises from the fact that a spiritual substance is a kind of self-subsistent thing. Now a form must have actual being in something else, that is, in matter, of which it is the act and the perfection. Hence, it seems to be contrary to the account of a spiritual substance that it should be the form of the body. For this reason, Gregory of Nyssa, (St. Gregory of Nyssa (ca. 335–395 AD) was the brother of St. Basil the Great and friend of St. Gregory Nazianzen; he was bishop of Nyssa in Cappadocia (see PG 45–46).) in his book On the Soul, (This reference is actually to an excerpt from chapter 2 of the work by Nemesius of Emesa: On the Nature of Man (PG 40:559–60B); see Gregory of Nyssa, On the Soul (PG 45:199).) accused Aristotle of asserting that the soul is not self-subsistent, and that it is corrupted when the body is corrupted, because he asserted it as the entelechy, that is, as the act or perfection, of the physical body.

But yet, if one carefully studies the matter, it becomes clearly evident that some substance must be the form of the human body. For it is obvious that understanding belongs to “this particular man,” as, for instance, Socrates or Plato. Now no activity belongs to any given thing except through some form which exists in the thing itself, either a substantial or an accidental form, because nothing acts or functions except in consequence of its being actual. (Cf. Aristotle, On Generation and Corruption 1.5, 320b17–19.) Now each individual thing is actual through some form, either substantial or accidental, since a form is an act; thus, for instance, fire is actually fire through “fireness,” and actually hot through heat. Accordingly, it must be the case that the principle of that activity which is understanding should be in “this man” in the way of a form. Now the principle of this activity is not a form whose actual being is dependent on matter and tied down to or immersed in matter, because this activity is not effected by means of the body, as its proven in On the Soul 3; (Aristotle, On the Soul 3.4, 429a24–27.) and hence, the principle of this activity possesses an activity that has nothing in common with corporeal matter. Now, the way in which each thing acts is a consequence of its being. Hence, the actual being of that principle must be an actual being which is raised above corporeal matter and not dependent on it. Now this is characteristic of a spiritual substance. It is necessary to say, therefore, if the preceding considerations are put together, that some kind of substance is the form of the human body.

But there are some who, while admitting that understanding is the act of a spiritual substance, have denied that such a spiritual substance is united to the body as a form. (Cf. SCG II.59.) Among these Averroes asserted that the potential intellect, in its actual being, is separated from the body. (Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 5; cf. Aquinas, Disputed Questions on the Soul, q. 2, resp.) He saw, nevertheless, that unless there were some union of it with “this man,” its act could not pertain to “this man.” For if there are two substances entirely unconnected, when one is acting or functioning, the other is not said to be functioning. And hence, he asserted that such an intellect, which he said was entirely separated from the body in its actual being, is connected with “this man” through phantasms, for this reason, that the intelligible species, which is a perfection of the potential intellect, is based on the phantasms from which it is abstracted. So, therefore, it has a two-fold kind of actual being: one in the potential intellect, of which it is the form, and the other in the phantasms from which it is abstracted. Now the phantasms are in “this man” because the imaginative power is a power within the body, that is, one which has a corporeal organ. The intelligible species itself, therefore, is the medium which joins the potential intellect to “the individual man.”

But this connection is in no way sufficient to explain the fact that “this individual man” understands. For, as Aristotle says in his book On the Soul 3, (Aristotle, On the Soul 3.7, 431a14–17; 3.5, 430a15–17.) the phantasms are related to the potential intellect as color is to the sight. Accordingly, the intelligible species abstracted from the phantasms is in the potential intellect in the same way as the species “color” is in the sense of sight. Now the intelligible species is in the phantasms in the same way as a species which makes seeing possible is in the physical object which is a wall.

Now owing to the fact that the species which makes seeing possible, the form “sight,” is based on the color of the wall, the act of seeing is not connected with the wall as with a seeing object, but as with a seen object: for by means of it the wall does not see, but is seen. For what constitutes a knower is not the fact that there is in him a form whose image is in some knowing power, but the fact that there is in him the cognitive power itself. And “this man,” accordingly, will not be one who understands because of the fact that in him are phantasms whose image, which is an intelligible species, is in the potential intellect. But it does follow because of this fact that his phantasms are understood by him. But the potential intellect itself, which is the understanding power, must be in “this man” in the way of a form, precisely in order that “this man” may understand.

He seems to have made a mistake also in regard to the account of the connection itself, since the intelligible species is not one with the potential intellect, save insofar as it has been abstracted from the phantasms, for only so is it understood in act, whereas insofar as it is in the phantasms it is understood only in potency. By this fact, then, is proved rather the disconnection of the potential intellect from the phantasms than its connection with them, for it must be the case that two things are entirely disconnected when something cannot be united to one of them, unless it has been previously separated from the other.

Setting aside this view then as impossible, we must consider that Plato produced a better result by asserting that “this man” understands, and yet that a spiritual substance is not united to the body as a form. For, as Gregory of Nyssa tells us, (It is actually Nemesius of Emesa, On the Nature of Man, ch. 3 (PG 40:593B–99B); see Gregory of Nyssa, On the Soul (PG 45:216).) Plato asserted that the intellectual substance which is called the soul is united to the body by a kind of spiritual contact; and this is understood in the sense in which a thing that moves or acts touches the thing that is moved or is passive, even though it be incorporeal. For this reason Aristotle says in On Generation and Corruption 1 (Aristotle, On Generation and Corruption 1.6, 322b22–24; 323a28–30.) that certain things touch and yet are not touched, because they act and are not passive. (Cf. Aristotle, On the Generation of Animals 2.1, 734a3–4.) And hence, Plato used to say, as the aforesaid Gregory relates, that man is not something that is composed of soul and body, but is a soul using a body, so that he is understood to be in a body in somewhat the same way as a sailor is in a ship, (It is actually: Nemesius of Emesa, On the Nature of Man, cc. 1, 3 (PG 40:505A, 593B).) and Aristotle seems to be touching upon this in On the Soul 2. (Aristotle, On the Soul 2.1, 413a8–9.) Thus, then, “this man” also understands, inasmuch as “this man” is the very spiritual substance which is the soul, whose proper act is understanding, even though, nevertheless, this substance does not exist as the form of the body.

But for the invalidation of this argument the one point suffices which Aristotle brings forward directly against this position in On the Soul 2. (Aristotle, On the Soul 2.1, 412b17–25.) For if the soul were not united to the body as a form, it would follow that the body and its parts would not have specific actual being through the soul, and this is seen to be obviously false. For once the soul departs, one does not say eye or flesh or bone, save equivocally, as one says painted eye or eye of stone. And hence, it is obvious that the soul is the form and the essence of this body, that is, that from which this body has the account of its own species. Exactly how this can be, however, we must proceed to investigate.

Now it must be borne in mind that the more perfect a form is, the more does it surpass corporeal matter. This is clear from induction in regard to the various orders of forms. For the form of an element does not have any activity but the one which takes place through active and passive qualities, which are the dispositions of corporeal matter. But the form “mineral body” has an activity that goes beyond active and passive qualities, and is a consequence of its species by reason of the influence of a heavenly body; for instance, that a magnet attracts iron, (Cf. Albert the Great, Quaestiones super De animalibus, bk. 16, q. 10, ad 1.) and that a sapphire cures an abscess. (Cf. Albert the Great, Book on Minerals, bk. 2, tract. 2, ch. 17.) And further, the vegetative soul has an activity to which the active and passive organic qualities of course contribute; but nevertheless, over and above the power of qualities like these, the soul itself achieves an effect of its own by nurture and growth up to a definite limit, and by carrying on other functions of this sort. And the sensing soul has a further activity to which the active and the passive qualities do not extend in any way, save insofar as they are needed for the composition of the organ through which this sort of activity is exercised, such as seeing, hearing, desiring, and the like.

But the most perfect of forms, the human soul, which is the end of all natural forms, has an activity that goes entirely beyond matter, and does not take place through a corporeal organ, namely, understanding. And because the actual being of a thing is proportioned to its activity, as has been said, since each thing acts according as it is a being, it must be the case that the actual being of the human soul surpasses corporeal matter, and is not totally included in it, but yet in some way is touched upon by it. Inasmuch, then, as it surpasses the actual being of corporeal matter, having of itself the power to subsist and to act, the human soul is a spiritual substance, but inasmuch as it is touched upon by matter and shares its own actual being with matter, it is the form of the body. Now it is touched upon by corporeal matter for this reason, that the highest point of the lowest always touches the lowest point of the highest, as Dionysius makes clear in the seventh chapter of On the Divine Names. (Pseudo-Dionysius, On the Divine Names, ch. 7, para. 3 (PG 3:871B).) Consequently, the human soul, which is the lowest in the order of spiritual substances, can communicate its own actual being to the human body, which is the highest in dignity, so that from the soul and the body, as from form and matter, a single being results. But if a spiritual substance were composed of matter and form, it would be impossible for it to be the body’s form. For it is essential to matter that it be not in anything else, but that it should itself be the primary subject.

Reply Obj. 1: A spiritual substance, although it is not completely grasped by the body, is, nevertheless, in some way or other touched upon by it, as has been said. (Above: resp.)

Reply Obj. 2: Understanding is an activity of the human soul, inasmuch as the soul goes beyond its relation to corporeal matter and consequently understanding does not come about through any corporeal organ. (Cf. Aquinas, Disputed Questions on the Soul, q. 2, ad 2.) Yet we may say that the composite itself, that is, man, understands, inasmuch as the soul, which is its formal part, has this proper activity, just as the activity of any part is attributed to the whole, for a man sees with his eye, walks with his foot, and in like fashion understands through his soul.

Reply Obj. 3: The soul has subsistent actual being, inasmuch as its own actual being does not depend on the body, seeing that it is something raised above corporeal matter. Yet it receives the body into a share in this actual being in such a way that there is one actual being of soul and of body, which is the actual being of a man. Now if the body were united to it in consequence of another actual being, it would follow that this union was accidental.

Reply Obj. 4: The soul by its very essence, and not on the basis of something added, is the form of the body. Nevertheless, inasmuch as it is affected by the body, it is a form; but inasmuch as it goes beyond a relationship with the body, it is called a spirit or a spiritual substance.

Reply Obj. 5: No part has the perfection of a nature when it is separated from the whole. And hence, the soul, since it is a part of a human nature, does not have the perfection of its own nature, save in union with the body. (Cf. Aquinas, Disputed Questions on the Soul, q. 1, resp.) This is clear from the following fact: the soul itself has such virtuality that certain powers which are not acts of corporeal organs flow from it, inasmuch as it goes beyond its relationship with the body; and again, that powers which are acts of the organs flow from it, inasmuch as it can be dependent on corporeal matter. Nor is a thing perfect in its own nature unless what is virtually contained in it can be actually brought out. And hence, the soul, although it can exist and can understand when separated from the body, nevertheless does not have the perfection of its own nature when it is separated from the body, as Augustine says in On the Literal Interpretation of Genesis 12. (Augustine, On the Literal Interpretation of Genesis, bk. 12, ch. 35, para. 68 (CSEL 28.1:432–33; PL 34:483).)

Reply Obj. 6: “Miracle” is not to be taken in that passage in the sense of something opposed to natural activity, but in the sense in which even natural works themselves are called miracles, seeing that they proceed from the incomprehensible power of God. (Alcher of Clairvaux, The Spirit and the Soul, ch. 14 (PL 40:790).) And in this sense Augustine says in Tractates on the Gospel of John (Augustine, Tractates on the Gospel of John, tract. 24, para. 1 (PL 35:1593; CCSL 36:244).) that the fact that God produces from a few seeds as great a number of sheaves of grain as is sufficient to feed the whole human race is more marvelous than that he fed five thousand men with five loaves of bread.

Reply Obj. 7: That through which a thing is weakened, once its nature has been presupposed, is not something natural. Nevertheless, it frequently happens that there is something which pertains to the nature of a thing, in consequence of which there nevertheless follows some weakness or defect in that thing; thus, for instance, to be composed of contraries is something natural to an animal, yet in consequence of this death and corruption follow in it. And, similarly, it is something natural for the soul to need phantasms for understanding, and yet in consequence of this it follows that the soul, in its understanding, is weakened by lower substances.

As for the statement that the soul is weighed down by the body, this is not a consequence of the body’s nature, but of its corruption, according to that passage in Wisdom 9:15: for a perishable body weighs down the soul. But as for the statement that the soul withdraws itself from corporeal connections in order to understand itself, this must be understood as meaning that it abstracts itself from them as it abstracts from objects, because the soul is understood through the negation of all corporeity. Yet the soul is not withdrawn from them in its actual being; nay, rather, if certain corporeal organs have been harmed, the soul cannot directly understand either itself or anything else, as when the brain is injured.

Reply Obj. 8: The higher a form is, the more does it need to be produced by a more powerful agent. Hence, since the human soul is the highest of all forms, it is produced by the most powerful agent, namely, God, yet in a way quite different from the way in which other forms are produced by any agents whatever. For the other forms are not subsistent. Hence, they do not possess actual being, but some things have being through them, and hence their coming into being is due to the fact that some matter or subject is brought from potency into act. And this is a bringing forth of the form from the potency of matter, without the addition of anything extrinsic. But the soul itself has subsistent actual being; hence, coming into being is strictly due to it, and the body is brought over to its actual being. On this account it is said that the soul exists from the outside and that it is not brought forth from the potency of matter. (Cf. Aristotle, On the Generation of Animals 2.3, 736b27–28; On the Soul 1.4, 408b18–19.)

Reply Obj. 9: Hence, the solution to the ninth argument is clear.

Reply Obj. 10: Spirit fits in with spirit rather than with body by a congruity of nature. But by a congruity of relationship which is required between form and matter, spirit fits in with body more than spirit does with spirit, since two spirits are two acts, whereas the body is related to the soul as potency is to act.

Reply Obj. 11: The angel and the soul are alike in their generic nature, inasmuch as both are intellectual substances. But the angel is superior in its specific nature, as Dionysius makes clear in the fourth chapter of Celestial Hierarchy. (Pseudo-Dionysius, The Celestial Hierarchy, bk. 4, paras. 1–2 (PG 3:177–79).)

Reply Obj. 12: “Rational,” understood in the strict sense, is the difference of “soul,” not of “angel,” but rather “intellectual,” as Dionysius uses the term. For an angel does not know truth through discursive reasoning but through simple insight, which is understanding in the strict sense. (Pseudo-Dionysius, On the Divine Names, ch. 7, para. 2 (PG 3:867).) Nevertheless, if “rational” be taken in a wide sense, then it must be said that it is not the ultimate specific difference, but is divided into other specific differences because of the different degrees of understanding.

Reply Obj. 13: The intellect is not said to be the act of any part of the body, inasmuch as it is a power that does not make use of an organ. Nevertheless, the soul’s very substance is united to the body as a form, as has been said. (Above: resp.)

Reply Obj. 14: With reference to those women, the running about is said to take place in the spirit, not that the spirit, that is, the substance of the soul, functions outside the body, but because visions of this sort are formed in the spirit, that is, in the soul’s imagination.

Reply Obj. 15: Matter without form, strictly speaking, cannot be a subject, seeing that “subject” is, strictly speaking, used of something that is actual being; but “living body” receives the character of actual being, so as to be able to be a subject, from no other form than the soul, as will be demonstrated below. (Below: a. 3, resp.)

Reply Obj. 16: “Corruptible” and “incorruptible” do not belong to the same genus, from the standpoint of natural philosophy, because of the different mode of actual being and the different account of potency in each; although they may belong to the same logical genus, which is understood on a basis of their intelligible concept alone. Now the soul, although it is incorruptible, is nevertheless in no other genus than the body because, since it is a part of a human nature, to be in a genus or in a species or to be a person or hypostasis is not characteristic of the soul, but of the composite. And hence, also, it cannot be called “this something,” if by this phrase is meant a hypostasis or person, or an individual situated in a genus or in a species. But if “this something” means everything that is able to be self-subsistent, in this sense the soul is “this something.”

Reply Obj. 17: That statement of the Commentator is impossible, as has been pointed out. (Above: resp.)

Reply Obj. 18: It is essential to intellectual substance that it be free from matter on which its being would depend as something totally tied down by matter. Hence, nothing prevents the soul from being an intellectual substance and the form of the body, as has been said above. (Above: resp.)

Reply Obj. 19: Out of a human soul and body a single thing comes into being in such a way that the soul nevertheless surpasses its relationship to the body; (Cf. ST I-II.2.6, resp.) and because of that part by which it surpasses the body, intellectual power is attributed to it. Hence, the intelligible species which are in the intellect need not be received in corporeal matter.