Article 2 — Whether the human soul, so far as its act of existing is concerned, is separated from the body

Second, it is asked whether the human soul, so far as its act of existing is concerned, is separated from the body. (Parallel texts: ST I.75.2; I.76.1; On Spiritual Creatures, a. 2; SCG II.56–59, 68; In II Sent., d. 1, q. 2, a. 4; d. 17, q. 2, a. 1; In III Sent., d. 5, q. 3, a. 2; d. 22, q. 1, a. 1; On Being and Essence, ch. 2; On the Unity of the Intellect, cc. 1–3; Commentary on Aristotle’s Metaphysics, bk. 7, lect. 9.)

Obj. 1: It seems that it is. For the Philosopher says that no sensitive power exists without a body, (Aristotle, On the Soul 3.4, 429b4–5.) yet the intellect is separate. However, the intellect is the human soul. Therefore, the human soul, so far as its act of existing is concerned, is separated from the body. (Cf. ST I.76.1, obj. 1.)

Obj. 2: Further, the soul is the act of a physical organic body inasmuch as the body is its organ. (Aristotle, On the Soul 2.1, 412b5–6.) Hence, if the intellect, with respect to its very act of existing, is united as a form to the body, the body must be its organ. This is impossible, as the Philosopher proves in the On the Soul 3. (Aristotle, On the Soul 3.4, 429a24–27, 429b4; cf. Aquinas, On Spiritual Creatures, a. 2, obj. 2.)

Obj. 3: Further, a form is united to matter more intimately than a power is to an organ. (Cf. SCG IV.81; On the Power of God, q. 3, a. 11, ad 11; ST I.60.3, obj. 2.) But the intellect cannot be united to the body as a power is to an organ, because the intellect is simple.

Obj. 4: But it might be said that the intellect, that is, the intellective power, does not have an organ, but that the essence itself of the intellective soul is united as a form to the body.

On the contrary, no effect is simpler than its cause. Now a power of the soul is an effect of its essence because all powers of the soul flow from its essence. (Aristotle, Physics 2.3, 195b25–28; Metaphysics 6.2, 1027a7–8; cf. SCG II.15, 56; In II Sent., d. 1, q. 2, a. 4, obj. 4; d. 17, q. 2, a. 1, obj. 2; ST I.76.1, obj. 4; On the Unity of the Intellect, ch. 3.) Consequently, no power of the soul is simpler than its essence. If, then, the intellect cannot be the act of the body, as is proved in On the Soul 3, neither can the intellective soul be united as a form to the body. (Aristotle, On the Soul 2.8, 420a24; 420b4; 3.4, 429a24–27; 429b5.)

Obj. 5: Further, every form united to matter is individuated by matter. (See above: q. 1, ad 2.) Therefore, if the intellective soul is united to the body as the form of the latter, the soul must be an individuated form. (Cf. Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 5.) Then the forms received in the soul are individuated forms. Consequently, the intellective soul will be incapable of knowing universals, which is clearly false.

Obj. 6: Further, a universal form does not acquire its universality from the thing existing outside the soul, because all forms existing in such things are individuated. Thus, if the forms in the intellect are universal, they must acquire this universality from the intellective soul. (Cf. Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 9.) Consequently, the intellective soul is not an individuated form, (See below: q. 3, obj. 8; Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 18.) and, therefore, is not united to the body so far as its act of existing is concerned.

Obj. 7: However, it might be said that intelligible forms are individuated inasmuch as they inhere in the soul; (See below: ad 5.) but, as the likenesses of things, they are universals representing things according to their common nature and not according to their individuating principles.

On the contrary, since a form is a principle of operation, an operation proceeds from a form in accordance with the manner in which that form inheres in a subject. For instance, the hotter something is, the more it is capable of heating. Therefore, if the species of things in the intellective soul are individuated because they inhere in the soul, then the knowledge which results will be knowledge only of the individual as such and will not be universal.

Obj. 8: Further, the Philosopher says that just as the triangle is contained in the quadrilateral, and the quadrilateral in the pentagon, so also is the nutritive part of the soul contained in the sensitive part, and the sensitive in turn contained in the intellective. (Aristotle, On the Soul 2.3, 414b27–32; cf. Aquinas, Commentary on Aristotle’s On Memory and Recollection, tract. 2, ch. 2.)

However, the triangle is not contained actually in the quadrilateral, but only potentially; nor is the quadrilateral contained actually in the pentagon. Therefore, neither the nutritive nor sensitive part of the soul is contained actually in the intellective. Consequently, since the intellective part of the soul is united to the body only through the intermediary of the nutritive and sensitive parts, because the sensitive and nutritive parts of the soul are not actually contained in the intellective part, the intellective part of the soul will not be united to the body.

Obj. 9: Further, the Philosopher says in On the Generation of Animals 2 that a man is not at once both an animal and a man, but first is an animal and then a man. (Aristotle, On the Generation of Animals 2.3, 736b2–4.) Consequently, the principle whereby he is an animal and that whereby he is a man are not one and the same. But he is an animal because of his sensitive part and a man because of his intellective part. Therefore, the sensitive and intellective parts are not united in one and the same substance of the soul. Hence, the conclusion is the same as the foregoing.

Obj. 10: Further, a form belongs to the same genus as the matter to which it is united. (Cf. SCG II.56.) But the intellect does not belong to the genus of corporeal things. Therefore, the intellect is not a form united to the body as to matter.

Obj. 11: Further, one being does not result from the union of two actually existing substances. (Cf. SCG II.56.) But both the body and the intellect (That is, the intellective soul.) are two actually existing substances. Hence, the intellect cannot be united to the body so that one being results from their union.

Obj. 12: Further, every form united to matter is given actual existence by moving and changing matter. But the intellective soul is not given actual existence by being educed from the potentiality of matter, but receives its act of existing from an extrinsic agent, as the Philosopher says in On the Generation of Animals 2. (Aristotle, On the Generation of Animals 2.3, 736b27–28; cf. Aquinas, On Spiritual Creatures, a. 2, obj. 9.) Therefore, the soul is not a form united to matter.

Obj. 13: Further, a thing operates in accordance with its nature. But the intellective soul has an operation of its own without the body, namely, the act of understanding. Therefore, so far as its act of existing is concerned, the intellective soul is not united to the body.

Obj. 14: Further, even the slightest impropriety is impossible for God. But it is improper for an innocent soul to be united to a body which is like a prison. Therefore, it is impossible for God to unite an intellective soul to a body.

Obj. 15: Further, a wise artisan does not place an obstacle in the way of his work. But the body is the greatest obstacle to the intellective soul in acquiring knowledge of truth, in which its perfection consists, according to that text in Wisdom: for a perishable body weighs down the soul (Wis 9:15). (Cf. Aquinas, In II Sent., d. 32, q. 2, a. 2, obj. 4; d. 1, q. 2, a. 4, obj. 1.) Therefore, God did not unite the intellective soul to the body.

Obj. 16: Further, things which are united one to another have an affinity for each other. But the intellective soul and the body are opposed to each other, because the desires of the flesh are against the spirit, and the desires of the spirit are against the flesh (Gal 5:17). (Cf. Avicenna, De anima, part 5, ch. 5.) Consequently, the intellective soul is not united to the body.

Obj. 17: Further, the intellect is in potency to all intelligible forms, having none actually, just as prime matter is in potency to all sensible forms, having none actually. (Cf. Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 5.) But it is for this reason that there is one prime matter for all things. Therefore, there is also one intellect for all men. (Cf. Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 1.) Hence, it is not united to a body which would individuate it.

Obj. 18: Further, the Philosopher proves in On the Soul 3 that if the potential intellect had a bodily organ, it would have a certain determinate sensible nature, and thus could not receive and know all sensible forms. (Aristotle, On the Soul 3.4, 429a18–27; cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 3, lect. 1; ST I.76.1, obj. 2; Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 4.) But a form is united to matter more intimately than a power is to an organ. Therefore, if the intellect is united as a form to the body, it will have a certain determinate sensible nature, and thus will be incapable of perceiving and knowing all sensible forms, which is impossible.

Obj. 19: Further, every form united to matter is received in matter. But whatever is received in a thing exists therein in accordance with the mode of the recipient. (Cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 12.) Therefore, every form united to matter exists in matter according to the mode of matter. But the mode of sensible and corporeal matter is not the one that a thing receives through an intelligible mode. Consequently, since the intellect has an intelligible mode of existing, it is not a form united to corporeal matter. (Cf. ST I.76.1, obj. 3.)

Obj. 20: Further, if the soul is united to corporeal matter, it must be received in it. But whatever is received in a thing that has received its act of existing from matter is received in matter. Therefore, if the soul is united to matter, then whatever is received in the soul is received in matter. But the forms of the intellect cannot be received in prime matter. On the contrary, they are made intelligible by abstraction from matter. Consequently, a soul which is united to corporeal matter is not capable of receiving intelligible forms, and thus the intellect, which is capable of receiving intelligible forms, will not be united to corporeal matter.

On the contrary (1), the Philosopher says in On the Soul 2 that it is unnecessary to ask whether the soul and the body are one, just as it is unnecessary to ask whether the wax and its impression are one. (Aristotle, On the Soul 2.1, 412b6–7.) But with respect to its act of existing, the impression cannot be separated in any way from the wax. Consequently, with respect to its act of existing, the soul is not separated from the body. But the intellect is a part of the soul, as the Philosopher says in On the Soul 3. (Aristotle, On the Soul 3.4, 429a10–11; 429a23.) Therefore, the intellect, so far as its act of existing is concerned, is not separated from the body.

Furthermore (2), so far as its act of existing is concerned, no form is separated from matter. But the intellective soul is the form of the body. Therefore, with respect to its act of existing, the soul is not separated from matter.

I answer that, in order to settle this issue, we must take into consideration that whenever a thing is found to be sometimes in potency and sometimes in act, there must be some principle by which it is in potency, just as a man is sometimes actually sensing and sometimes only potentially. Now, on account of this, it is necessary to maintain that in man there exists a sensitive principle which is in potency to sensible things; for if he were always actually sensing, the forms of sensible things would always actually exist in his sensitive principle. Similarly, since a man is found sometimes to be actually understanding and sometimes only potentially, it is necessary to maintain that in man there exists an intellective power which is in potency to intelligibles; (Aristotle, On the Soul 3.5, 430a10–15; cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 3, lect. 4.) and the Philosopher, in On the Soul 3, calls this principle the potential intellect. (Aristotle, On the Soul 3.5, 429a21–22; 429b30–31; 430a14–15. Throughout this translation, we have translated intellectus possibilis as “potential intellect” rather than as “possible intellect” or “passive intellect.” While “possible intellect” is a common and more direct transliteration of the Latin, the term in English might confusingly suggest the opposite of impossibility rather than the intellect’s potency to the intelligible. As for “passive intellect,” this term has been reserved for the intellectus passivus that Aquinas identifies with the bodily cogitative power in the response to q. 13 below.) Consequently, this potential intellect must be in potency to all things intelligible to man; it must be capable of receiving them and, therefore, must be devoid of them, because anything capable of receiving other things is in potency to them inasmuch as it lacks them, just as the pupil of the eye, which is capable of receiving all colors, lacks every color. Now man is determined by nature to understand the forms of all sensible things. Therefore, the potential intellect, by its very nature, must be devoid of all sensible forms and natures, and so also must have no bodily organ. For if it had a bodily organ, it would be limited to some sensible nature, just as the power of vision is limited to the nature of the eye. (Cf. Aquinas, SCG II.59; Commentary on Aristotle’s On the Soul, bk. 3, lect. 1; On the Unity of the Intellect, ch. 1.)

By means of this proof we exclude the position of the ancient philosophers, (Cf. Aristotle, On the Soul 1.2, 404b7–18; 405b12–13; Aquinas, In II Sent., d. 19, q. 1, a. 1, resp.; SCG III.84; Commentary on Aristotle’s On the Soul, bk. 1, lect. 2, 4, 5; bk. 2, lect. 28.) who held that the intellect did not differ from the sensitive powers, as well as the position of those who maintained that the principle by which a man understands is a certain form or power which is united to the body as other material forms or powers are. (For example, Alexander of Aphrodisias (fl. 200 AD), according to Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 5; cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 3, lect. 1.)

But certain other men, avoiding this position, fall into the opposite error. (SCG II.56.) For they think that the potential intellect is devoid of every sensible nature and that it is not present in the body because it is a certain substance which exists in separation from the body and is in potency to all intelligible forms.

But this position cannot be maintained, because we acquire our knowledge of the potential intellect only so far as a man understands by it. Indeed, this is the way Aristotle obtains his knowledge of it, as is evident from what he says in On the Soul 3 when he begins to discuss the potential intellect: concerning that part of the soul by which the soul knows and perceives . . . it must be considered . . . ; (Aristotle, On the Soul 3.4, 429a10–11.) and in another place he says, I speak of the potential intellect by which the soul understands. (Aristotle, On the Soul 3.4, 429a23.)

But if the potential intellect were a separate substance, it would be impossible for a man to understand by means of it because, if a substance performs an operation, that operation cannot belong to any other substance than the one performing it. For although one of two substances can be the cause of the other’s operation, as the principal agent is the cause of the activity of the instrument, nevertheless the action of the principal agent is not numerically the same as that of the instrument. For the action of the principal agent consists in moving the instrument, whereas that of the instrument consists in being moved by the principal agent and in moving something else. Consequently, if the potential intellect is a substance existing apart from this or that particular man, it is impossible for the potential intellect’s act of understanding to be the act of any particular man. From this it follows that no man understands anything, because the act of understanding is not attributed to any principle in man except the potential intellect. (Cf. ST I.76.1, resp.; Aquinas, Commentary on Aristotle’s On the Soul, bk. 3, lect. 1; Compendium theologiae, bk. 1, ch. 85; On Spiritual Creatures, a. 2; On the Unity of the Intellect, ch. 3.) Hence, the same manner of arguing is opposed to this position and to those who deny its principles, as is evident from Aristotle’s arguments against them in Metaphysics 4. (Aristotle, Metaphysics 4.3, 1005b25; 4.4, 1006a12–24.)

Now Averroes, who is a follower of this position, intending to avoid its incongruity, maintained that the potential intellect, although it existed apart from the body, must be united to man through the intermediary of phantasms. (Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 5.) For phantasms, as the Philosopher says in On the Soul 3, are related to the potential intellect as sensible things are to sense, and colors to sight. (Aristotle, On the Soul 3.5, 430a14; 3.7, 431a14–15.) Thus, an intelligible species has two subjects: one in which it exists with an intelligible mode of existing, and this is the potential intellect; another in which it exists with a real mode of existing, and this subject is the phantasms. (Averroes, Commentary on Aristotle’s On the Soul, bk. 3, comm. 5.) Therefore, (That is, according to Averroes.) there is a certain union of the potential intellect with the phantasms inasmuch as an intelligible species exists in a certain manner in each of these subjects; and a man understands through the potential intellect (Note that the potential intellect is supposedly separate from the individual man according to this view.) as a result of this union with the phantasms. (Cf. Aquinas, In II Sent., d. 17, q. 2, a. 1; SCG II.73; ST 1.76.1; Commentary on Aristotle’s On the Soul, bk. 3, lect. 1; On Spiritual Creatures, a. 2; On the Unity of the Intellect, ch. 3.)

However, this union is still not sufficient to account for man’s knowledge, for a thing is capable of knowing, not because intelligible species are present to it, but because it possesses a cognitive power. Now evidently, from what has been said, intelligible species alone will be present to man, whereas the power of understanding, that is, the potential intellect, exists in complete separation from him. Therefore, it does not follow from the aforesaid union that a man will have what is necessary for understanding, but only that a species or something in that intellect will be understood. This clearly appears to be the case from the simile introduced above. For if phantasms are related to the intellect as colors are to sight, the union of the potential intellect with us through our phantasms will be the same as that of sight with a wall through its colors. Now it does not follow that a wall sees because it has colors, but only that it is seen. Nor, similarly, does it follow that a man will understand because phantasms are present within him, but only that he will be understood. (Cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 3, lect. 1.)

Furthermore, a phantasm is not the subject of an intelligible species inasmuch as the latter is actually understood. On the contrary, an intelligible species is made to be actually understood by abstraction from phantasms. Moreover, the potential intellect is the subject of an intelligible species only inasmuch as an intelligible species is now actually understood and abstracted from phantasms. Therefore, the species existing in the potential intellect and that existing in the phantasms, through which the potential intellect (Again, in this position of Averroes, the potential intellect is supposedly separate.) is united to us, are not one and the same.

Furthermore, if anyone understands through intelligible species only when they are understood in act, it follows, according to the aforesaid position, that we are incapable of understanding anything in any way, for then intelligible species would be present to us only inasmuch as they exist in phantasms, and here they are only potentially understood. (Cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 3, lect. 1.)

Consequently, it is evident on the side of our human nature that the above-mentioned position is impossible. This is also apparent from the nature of separate substances. Since these are most perfect, it is impossible for them in their own operations to stand in need of the operations of material things; nor need they be in potency to any things of this kind, for not even the heavenly bodies, which are below the separate substances, require things of this sort. Hence, since the potential intellect is in potency to the species of sensible things, and since its operation may not be completed without phantasms, which depend on our operations, it is impossible and inconceivable for the potential intellect to be one of the separate substances. (Cf. SCG II.96; On the Unity of the Intellect, ch. 3.)

Consequently, we must say that the potential intellect is a certain faculty or power of the human soul. For although the human soul is a form united to the body, it is not embraced completely by the body as though immersed in it as other material forms are, but transcends the capacity of the whole of corporeal matter. And so far as the soul transcends corporeal matter, the potentiality for intelligibles exists in the soul, and this potentiality belongs to the potential intellect. Certainly the soul, so far as it is united to the body, has operations and powers in common with the body; such, for example, are the powers of the nutritive and sensitive part. Thus, the nature of the potential intellect is as Aristotle proves it to be, for the potential intellect is not a power rooted in any bodily organ. (Aristotle, On the Soul 3.4, 429a21–27.) However, a man understands formally by means of it inasmuch as it is rooted in the essence of the human soul, which is the form of man. (Cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 3, lect. 1; On the Unity of the Intellect, ch. 1.)

Reply Obj. 1: The intellect is said to be separate, but not the senses, because the intellect remains in the separated soul when the body has corrupted, whereas the senses do not. Or, a better way of stating it is to say that the intellect is said to be separate because it does not employ a bodily organ in its operation as the senses do.

Reply Obj. 2: The human soul is the act of an organic body because the body is its organ. However, the body need not be the organ of all the soul’s active and passive powers since the human soul exceeds the capacity of the body, as we have explained. (Above: resp.)

Reply Obj. 3: The organ of a power is the principle of that power’s operation. Hence, if the potential intellect were united to an organ, its operation would also be the operation of that organ, and thus it would be impossible for the principle by which we understand to lack every sensible nature. For this principle by which we understand would then be the potential intellect together with its organ, just as the principle whereby we see, namely the power of vision, exists concurrently with the pupil of the eye. (Cf. Aquinas, On the Power of God, q. 3, a. 9, ad 22; Commentary on Aristotle’s On the Soul, bk. 2, lect. 26.) However, even though the human soul is the form of the body, and the potential intellect is one of the soul’s powers, it does not follow that the potential intellect is limited to some sensible nature, because the human soul transcends the capacity of the body, as we have explained. (Above: resp.)

Reply Obj. 4: The potential intellect belongs to the human soul inasmuch as the soul is elevated above corporeal matter. Consequently, because the intellect is not the act of an organ, it does not completely exceed the essence of the soul, but is the greatest thing in it.

Reply Obj. 5: The human soul is an individuated form, and so also is its power, which is called the potential intellect, as well as the intelligible forms which are received in the potential intellect. But this does not prevent these forms from being actually known, for a thing is actually known because it is immaterial, not because it is universal. (Cf. ST I.76.2, ad 3; On the Unity of the Intellect, ch. 5.) Indeed, the universal is intelligible because it is abstracted from material individuating conditions. Moreover, it is evident that separate substances are actual intelligibles and yet are certain individual entities, just as Aristotle says in Metaphysics 7 that the separated forms which Plato claimed to exist were individual things. (Aristotle, Metaphysics 7.13, 1039a23; 7.15, 1039b32; 1040a8–9; 1040a25–30.) Therefore, if individuation is incompatible with intelligibility, it is evident that the same difficulty remains when the intellect is considered to be a separate substance; for then the potential intellect would be individuated as well as the species which are received in it. Consequently, we must understand that, although the intelligible species received in the potential intellect are individuated inasmuch as they exist in the potential intellect, still the universal, which is conceived by abstraction from individuating principles, is known in these species inasmuch as they are immaterial. (Cf. Aquinas, In II Sent., d. 17, q. 2, a. 1, ad 3; On Truth, q. 10, a. 4, resp.) For universals with which the sciences are concerned are what are known through intelligible species, and not the intelligible species themselves. (Cf. Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 12.) Moreover, concerning these intelligible species, not all sciences study them, but only physics and metaphysics. For an intelligible species is that by which the intellect knows, but not that which it knows (Cf. Aquinas, ST I.85.2; Commentary on Aristotle’s On the Soul, bk. 3, lect. 2.)—except by reflection inasmuch as it knows that by which it knows in order to know itself. (Cf. ST I.87.1, 3; Commentary on Aristotle’s On the Soul, bk. 3, lect. 3.)

Reply Obj. 6: The intellect gives universality to the forms known inasmuch as it abstracts them from material individuating conditions. Consequently, it is not necessary that the intellect be universal, but that it be immaterial.

Reply Obj. 7: The species of an operation is a natural effect of the species of the form which is the principle of that operation, whereas the ineffectiveness of an operation is a natural effect of the form inasmuch as it inheres in a subject. (Cf. ST III.19.1, ad 3.) For a thing heats because it is hot, but it heats more or less effectively according as heat perfects it to a greater or lesser degree. Now to understand universals pertains to the species of intellectual operation. Hence, this activity is the natural effect of an intellectual species as its proper operation; but so far as this activity is exercised more or less perfectly by the one understanding, it follows that the one understanding does so in a more or less perfect way.

Reply Obj. 8: The resemblance which the Philosopher observes between geometrical figures and the parts of the soul is to be regarded in this way: just as a quadrilateral contains the elements of a triangle and additional characteristics, and a pentagon the elements of a quadrilateral, so also does the sensitive soul possess the characteristics of the nutritive, and the intellective possesses the characteristics of the sensitive and others as well. Therefore, it is not shown in this way that the nutritive and sensitive parts of the soul differ essentially from the intellective, but rather that one of these parts contains another. (Cf. ST I.76.3, resp.; On Spiritual Creatures, a. 3; Commentary on Aristotle’s On the Soul, bk. 2, lect. 5.)

Reply Obj. 9: Just as animal and man are not conceived simultaneously, so neither are animal and horse, as the Philosopher points out in the same place. (Aristotle, On the Generation of Animals 2.3, 736b2–3.) Therefore, this statement is not based on the argument that the sensitive soul, existing substantially in man, is a principle by which he is an animal, and the intellective soul another principle by which he is a man. For it cannot be said that there are many different principles in a horse, one making it an animal, another a horse. But this statement is made for this reason, that in the concept of animal the imperfect operations appear first, and then the more perfect, just as every generation is a transition from the imperfect to the perfect. (Aristotle, Physics 8.7, 261a13–14.)

Reply Obj. 10: A form does not belong to a genus, as has been shown. (Above: q. 1, ad 13.) Consequently, since the intellective soul is the form of man, it does not belong to a different genus from that of the body. But each belongs to the genus of animal and the species of man by reduction.

Reply Obj. 11: One being does not result from the union of two actually existing substances complete in their species and nature. Now the soul and the body are not substances of this sort, because they are parts of human nature. Therefore, nothing prevents them from being united to form one being.

Reply Obj. 12: Although the human soul is a form united to a body, it totally transcends the capacity of the whole of corporeal matter, and, therefore, cannot derive actual existence from the potentiality of matter as a result of any motion or change, as do other forms which are immersed in matter. (Cf. Aquinas, In II Sent., d. 18, q. 2, a. 1; SCG II.86, 88–89; On the Power of God, q. 3, aa. 9, 11; ST I.90.2; I.118.2; Compendium theologiae, bk. 1, ch. 93.)

Reply Obj. 13: The soul, through that part of it whereby it exceeds every capacity of the body, has an operation in which the body does not share. However, this does not prevent the soul from being united to the body in some way.

Reply Obj. 14: This objection agrees with the position of Origen, (Cf. Origen, On the First Principles, bk. 1, ch. 7, paras. 4–5; bk. 3, ch. 5, para. 4; Jerome, Contra Joannem Hierosolymitanum, bk. 1, para. 7 (PL 23:360B); Aquinas, Commentary on Aristotle’s On the Soul, bk. 2, lect. 2.) who maintained that in the beginning souls were created without bodies together with the spiritual substances and afterwards were united to bodies as though shut up in prisons. (Cf. Aquinas, On Truth, q. 10, a. 6; SCG II.44, 83; On the Power of God, q. 3, aa. 9, 10; ST I.118.3.) However, he did not say souls suffered that innocently but because of a preceding sin. Hence, Origen, in accordance with the position of Plato, held that the human soul was a complete species in itself, and that the body was joined to it accidentally. (Cf. Nemesius, On the Nature of Man, cc. 1–3.) But since this is false, as we have shown above, (Above: q. 1, resp.) it is not detrimental to the soul to be united to a body; on the contrary, this union makes for the perfection of its nature. However, that the body is the prison of the soul and taints the soul is merited by the first sin.

Reply Obj. 15: It is natural to the human soul to apprehend intelligible truth in a manner inferior to that proper to superior spiritual substances, namely, by abstraction from sensible things. But in this also the soul suffers an impediment through the corruption of the body which results from the sin of the first parent.

Reply Obj. 16: The fact that the flesh desires things that are opposed to the spirit shows the affinity of the soul for the body. For “spirit” signifies the superior part of the soul whereby man surpasses other animals, as Augustine says in On Genesis Against the Manichees. (Augustine, On Genesis Against the Manichees, bk. 2, ch. 8 (PL 34:201–2).) But the flesh is said to desire because the parts of the soul joined to the flesh desire those things which delight the flesh, and now and again these concupiscences fight against the spirit.

Reply Obj. 17: The potential intellect does not possess any intelligible form actually, but only potentially, just as prime matter does not have any sensible form actually. Therefore, it is not necessary, nor does the argument prove, that the potential intellect is one and the same for all men. It only shows that their intellect is open with respect to all intelligible forms, just as prime matter is one with respect to all sensible forms.

Reply Obj. 18: If the potential intellect had a bodily organ, that organ would have to be a principle (Namely, a principle of understanding.) together with the potential intellect which is the cause of understanding, just as the pupil of the eye together with the power of vision is the principle of vision, (See above: ad 3.) and thus the principle by which we understand would have a determinate sensible nature. This is evidently false in view of Aristotle’s demonstration that was given above. (Aristotle, On the Soul 3.4, 429a18–27.) However, this does not follow from the fact that the soul is the form of the body, because the potential intellect is a power of the soul insofar as it transcends the capacity of the body.

Reply Obj. 19: Although the soul is united to the body in accordance with the body’s mode of existing, still the soul has an intellectual nature in virtue of that part whereby it transcends the capacity of the body, and thus the forms received in the soul are intelligible and not material.

Reply Obj. 20: From this the solution to the twentieth objection is evident.