Commentaria in Summam contra Gentiles, Liber II

With the errors concerning the intellect and the intellectual soul excluded and eliminated—errors by which some wished to escape the conclusion that a spiritual substance can be the form of the body—Saint Thomas comes, in the third place, to the determination of the truth ¹, and he wishes to show that a spiritual substance can be the form of the body.

On this point he does two things. First, he shows that such a substance can be united to the body as its form. Second, he shows that although it is united to the body, it is nevertheless not wholly comprehended by matter, nor immersed in it as other material forms are; this concerns the middle of this chapter ².

I. First he proves it with three arguments. But before the conclusion is proved, it must be noted that the statement that a spiritual substance can be united to a body as its form is to be understood in the way shown above, chapter LXV ³, namely that living things are composed of soul and body in reality. For it is not so taken as if the said substance could inform a composite of matter and a corporeal form distinct from the spiritual substance and remaining together with it in the same composite. This is indeed impossible, according to the doctrine of St. Thomas, who holds that in one substantial composite there can be only one substantial form. But by the name "body" is understood either matter under quantity, which is understood to precede the form in matter according to the order of material causality, though according to the order of formal causality it is the reverse; or a body preexisting the soul, which nevertheless, upon the arrival of the soul, is corrupted in its substance but remains in virtue in the composite of matter and the intellective soul.

This having been declared, it is argued first to the conclusion from a sufficient division, thus. An intellectual substance is not united to the body only as mover, as Plato held, nor is it continued to it only through phantasms, as Averroes said, but as form. Nor yet is the intellect by which the human soul understands a preparation in human nature, as Alexander said; nor a complexion, as Galen; nor a harmony, or body, or sense, or imagination, as the ancients said. Therefore the human soul is a spiritual substance united to the body as form. Therefore etc.

II. Second, ⁴. A spiritual substance can be the formal principle of the substantial being of matter, and it can agree with matter in being one. Therefore it can be the form of a body.

The consequence is evident. For those two things are required as sufficient for something to be the substantial form of a thing: namely, that it be the principle of substantial esse for that of which it is the form—that is, a principle not effective but formal, by which something is and is denominated a being; and that form and matter agree in one esse, in which the substance composed of matter and form subsists, which is one in its esse—something that does not belong to an effective principle together with that to which it gives esse.

The antecedent, however, is proved with respect to both parts. With respect to the first: because if that could not belong to a spiritual substance, this would be so far because it is subsistent, as was proved above; for it seems repugnant to a subsistent thing that it be the formal principle of the being of matter, as it were communicating its esse to matter. But this does not stand in the way. For it is not unfitting that the esse in which the composite subsists and that of the form itself should be one and the same: since the composite exists only through the form, nor does each subsist separately, and consequently for the form to be the esse of another does not take away subsistence from it.

As for the second part, it is proved as follows: because, if anything prevented the spiritual substance and matter from being one esse, this would be so insofar as they are of different genera, and substance is nobler than matter; but things of different genera have a different mode of being, and the esse of a nobler substance is nobler. Yet this is no obstacle: because that esse does not belong to the spiritual substance and to matter in the same way. For it belongs to matter as to a recipient and subject elevated toward something higher, but to the spiritual substance as to a principle, and according to the congruence of its own nature.

3. For the clarification of the proof of the first part of the antecedent, it must be considered that if we were to take self-subsistent esse as identical with a "this something" taken properly—that is, as a subsistent complete in the nature of some species—it would indeed be repugnant for subsistent esse to be the form of any matter: for what is complete in itself in species cannot be a part of another species, as is said in Metaphysics VII ⁵. But Saint Thomas does not take self-subsistent esse in this way here; rather, he takes it as excluding the inherence of an accident and of material form. For thus to subsist is to have an esse independent of subject and matter. Hence the intellective soul is said to be subsistent, because it has an esse not dependent on matter, since it is not immersed in matter nor educed from the potency of matter. But it is not repugnant for such a subsistent to be the formal principle of the being of matter: for something can communicate its own esse formally to matter and yet not depend on matter with respect to its esse.

Concerning the second part of the antecedent and its proof, it must be noted that the intellectual soul, since it is a substance not dependent upon matter with respect to its esse, belongs in some way to the order of immaterial and intellectual substances. But all other substantial forms, since they depend upon matter with respect to their esse and are educed from the potency of matter, belong entirely to the order of sensible and material things. From this it follows that, when matter is informed by some material form, it is not said to be drawn toward something of a higher order and elevated, since both the matter and the material form pertain to the same order of things. When, however, matter is informed by the intellectual soul, it is drawn toward an esse of a higher order: because the intellectual soul, to which its own esse befits in accordance with the congruence of its proper nature, belongs to the genus of immaterial things, which genus is higher and more dignified than the genus of sensible things. Nor is it unfitting that what is of a lower order should be drawn in some way and elevated to a certain participation in a higher order: for we see in ourselves that the cogitative power, which pertains to sensitive nature, is elevated to a certain participation in reason and intellect because it is rooted in the same essence of the soul as the intellect, when it forms particular propositions and reasons about singulars. On account of these considerations, then, Saint Thomas rightly says that the esse of a spiritual substance informing matter is that of matter as a subject elevated to something higher.

III. But concerning the whole of the foregoing and its proofs together there is doubt. For it seems to follow from what has been said that the esse in which the intellective soul subsists is the same as that of the composite of it and matter, which is man. This, however, does not please Scotus, in Book IV, d. 43, q. 1, and in his Quodlibets, q. 9; indeed, he argues against it in many ways.

And first, thus ⁶ Every being has some proper esse. Man, as man, is some being: not merely a soul. Therefore he has some proper esse, and not merely the esse of the soul.

Secondly ⁷. In this St. Thomas seems to contradict himself. For he holds elsewhere, namely in IV Sent., d. xliii, q. 1, a. 1, quª 1, ad 4, that "the state of the soul in the body is more perfect than its state outside the body, because it is a part of the composite, and every part is material with respect to the whole." Then the argument runs thus. That which has entirely the same proper esse is not less perfect on this sole ground that it does not communicate that esse to another, since perfection is naturally presupposed to the communicating of perfection. But, by your account, the soul has entirely the same esse when separated and when joined—indeed, an esse which is the total esse of man when it is communicated to the body. Therefore it is in no way less perfect on account of not communicating the same esse to the body. You said the opposite of this.

Third ⁸. It would follow that the soul is not less perfect in being than man. This is false. Therefore, and so on. — The consequence is proved: because things having the same esse are equally perfect in being.

Fourth ⁹. The esse of the composite is corrupted: for the esse of the whole does not remain unless the whole having that esse remains; and universally, the actual esse of anything does not seem to remain the same unless that which actually has that esse remains. But the esse of the soul is incorruptible. Therefore the esse of the soul is not the same as the esse of man.

For these reasons he himself distinguishes, where above, in the Quodlibetal Questions, between a twofold esse, saying that it can be taken in two ways. In one way, for that by which something first formally recedes from non-being: and this is that by which something is outside the intellect and the power of its cause. In another way, for the ultimate act, to which, namely, no other act comes that gives esse simpliciter; and that is said to have esse simpliciter to which this esse so called first belongs—first, I say, in such a way that it is not the reason of being by that esse for any other. According to the first mode, every being outside the intellect and its cause has its own proper esse. With respect to the second mode, however, only the perfect composite in a species has esse simpliciter: but a part of it is said to be only per accidens, or, more properly, participatively, through that esse of the whole.

From these I draw two conclusions. The first is that the intellective soul is a being in itself, taking esse in the first way; but not in the second way, except improperly and secundum quid. — The second is that the esse of the form and of the whole is not the same when taken in the first way, but well enough so in the second way: although it is not the same for each in the same manner, but belongs to the whole in the first way and to the part participatively.

IV. To make the difficulty evident, three things must be done: first, Scotus's position will be briefly impugned; second, the position of Saint Thomas will be explained ¹⁰; third, a reply will be given to the arguments ¹¹.

As to the first, it is argued against this position in two ways. First, thus. It is supposed first that a form, before it comes to matter, has no esse in act in nature: because it is not outside the power of its cause except when it is produced in matter; unless we wished to posit forms as existing before matters, which is rejected by the Philosopher, Metaphysics XII ¹². — It is supposed second that in the same real instant in which the form comes to matter, the composite is constituted and results from matter and form, and that composite receives esse.

Then the argument proceeds thus. In the same instant the form is united to matter, and there is a composite of matter and form. Therefore in the same instant the form receives actual esse, and so does the composite. But, by your account, these esse of actual existence are distinct. Therefore in the same instant there are two esse from one form. This is false. Therefore some premise is false. Not the first antecedent: from the second supposition. Nor the first consequence: from the first and second suppositions. Therefore the minor subsumed: which was your position. — The falsity of the consequent is proved. From one form there is only one formal effect: for one whiteness makes one being white. But the esse of actual existence is a formal effect of the form. Therefore from one form there will be only one actual esse. There will not therefore be one actual esse of the form, and another actual esse of the composite.

2. Second. The intellective soul has an actual esse other than the esse of the composite. Therefore both it and the composite will be a being per se, taking esse in the second way. But this is against your position. Therefore the antecedent is not true.

The consequence is proved. The esse by which the intellectual soul exists is the ultimate act, to which no other act giving esse simpliciter accrues; and that soul, to which this esse belongs first, such that it is not for any other the ground of being by that esse, is said simply to have esse. Therefore the soul is a being per se in that way. And likewise, by your own account, the composite is a being per se. Therefore etc. — The consequence is evident from your position.

The antecedent is proved. As to the first part: because in man there is no other form arriving at the intellectual soul that gives it substantial esse and esse simpliciter. For it is evident that no form of a part arrives in man after it, since through it man is man. — Nor does a form of the whole arrive, which is the essence, as giving esse simpliciter: for the essence of the composite is not the formal principle of being simpliciter, and least of all of a part; rather, it is the proper recipient of esse. — Nor does any other esse arrive. First, because one actual existence is not informed by another such that it would be in act by another actual existence: just as neither is one whiteness white by another whiteness. Second, because that other esse could not be anything other than the esse of the composite: but this does not make the intellectual soul exist simpliciter, but the composite, while the soul exists per accidens or participatively, as you say. — Therefore the esse by which the intellectual soul exists is the ultimate act, to which no other act arrives giving esse simpliciter.

As to the second part, it is also proved: because of the soul, to which its own proper esse belongs in such a way that by means of that esse it is nothing else, it can truly be said absolutely that it is; and that esse, according as it is said to be, it has integrally and perfectly, and not merely participatively. Therefore the soul may be said to have esse simpliciter through that esse. — The consequence is evident. Because it is true to say of something that it has esse simpliciter, even according to you, when without any addition it is true to say of it that it is, and not merely participatively does it have that esse by which being and existing are said. — The antecedent, however, is proved, as to its first part, from the difference between substantial and accidental esse. For by substantial esse a thing is said to be absolutely and without any other addition; but by accidental esse it is said to be with some addition, not absolutely: for by the esse of whiteness a wall is not said to be absolutely, but to be white, and so for other accidental esses; but by the esse of the soul we say that man is absolutely, and so for the others. Hence among all philosophers a substantial form differs from an accidental one because the substantial form gives esse simpliciter, while the accidental gives esse secundum quid. — As to the second part, however, it is proved: because the esse that belongs to the soul, distinct from the esse of the composite, is proper to it according to you. Therefore it belongs to it not participatively from another to whom it would belong first.

V. As to the second point ¹³, for the exposition of the opinion of Saint Thomas, it must be considered that, since the intellectual soul is produced entirely from without, while the other forms are drawn forth by a natural agent from the potency of matter; yet let the soul be a form of matter just as the other material forms are: in some respects it agrees with the other specific forms, and in some respects it differs.

For it agrees with them in three respects, and in three respects it differs. First, it agrees because through the union of both forms with matter the composite is constituted, which is receptive of the esse of actual existence, and it has a complete essence in the species. — Second, because each form gives esse both to the matter and to the composite. — Third, because by one and the same esse the matter, the form, and the composite exist. For since there is only one substantial form of one thing, it must also have only one actual esse: for from one form there is only one esse, as we have already proved ¹⁴.

They differ, first, because those forms do not subsist in their esse, but have an esse dependent on matter: since they are drawn out of the potency of matter, being as it were comprehended by matter, and not exceeding the order of material things. The intellective soul, however, is of itself subsistent in its esse: for it is not drawn out of the potency of matter, and it has an esse not dependent on matter; although in its coming-to-be, and from its beginning, it receives esse in the soul itself. Hence it does indeed come to be only in matter, but nevertheless without matter, when it is separated from matter, it retains its esse. — Second, because the esse that a material form gives, since it is material just as the material form is material, belongs first and of itself to the composite of matter and form, as to that which holds the degree of perfection in material nature; secondarily, however, it belongs to the form, inasmuch as the form is a part of the composite. But the esse that the intellective soul gives is in itself immaterial, just as that form itself is immaterial: therefore it belongs first and of itself to the soul, which is immaterial; secondarily, however, it belongs to the composite, namely as to that which is in some way elevated to the order of immaterial things through the intellective soul. — Third, because the esse that a material form gives, since it belongs first and of itself to the composite, does not remain when the composite is corrupted. But the esse of the intellective soul, because it belongs not first and of itself to the composite but to the soul itself, does not cease when the composite is corrupted, but remains in the soul itself, which draws back to itself the esse that it communicated to matter.

From these things it is clear that it is not necessary that the esse of the intellectual soul be one thing and the esse of man another, speaking of esse as actual existence, just as neither in material things is the esse of the form one thing and that of the composite another: but by the same esse both the intellectual soul and man exist, the former indeed primarily, but man secondarily.

VI. But two doubts arise concerning what has been said. The first concerns the statement that the intellectual soul is not educed from the potency of matter, and therefore has subsistent esse. For if this is so, it follows that the intellectual soul is not in the potency of matter: for it is repugnant that it be in the potency of matter, and that, when it is actually introduced into matter, it is not educed from the potency of matter. But this is false: because then the generation of man would not be natural; for through it a natural form would not be introduced into matter, but a supernatural form.

The second reason is this: it was said that esse belongs to man first and per se to the soul, and only secondarily to man. But this does not seem true. For each thing is related to operating as it is related to esse, and conversely, as is stated in the Prima, q. 75, a. 2. But operating belongs first and per se to man, not to the soul, at least with respect to the operations of the sensitive and vegetative parts, since those are operations of the composite. Therefore esse belongs first and per se to man, not to the soul.

2. To the first of these it is said, from the teaching of Saint Thomas in the Prima, q. 90, a. 2, ad 2, and in De Spiritualibus Creaturis, a. 2, ad 8, and likewise below in this Second Part, chapter LXXXVI, that for a form to be drawn out of the potency of matter is nothing other than for matter to be drawn out of potency into the act of that form, namely because the form was previously in matter potentially and indistinctly, but afterwards, through the transmutation of matter, it comes to be in act in that very matter. Hence, in order that a form be drawn out of the potency of matter, it is necessary that it first be contained in it as in a material cause; and consequently that it depend upon it according to the genus of material cause; which is to say that, according to its esse, it is sustained by matter in such a way that it cannot be without matter. Since, therefore, the intellective soul does not depend upon matter according to its esse, it is clear that it is not drawn out of the potency of matter: and consequently that it is not contained in the potency of matter; I say natural potency, however, not obediential potency.

Therefore falsity of the consequent is denied. And when it is argued that the generation of a man would not be natural, the consequence is denied. For natural generation is said to be not only that by which matter is led from potency into act of a form preexisting in that natural potency, but also that by which a form which was not in matter in natural potency, but is produced only from without, is united to matter by a natural agent. For the material dispositions disposing toward the union of the soul with matter, which are the ultimate requirement for the form, are natural, and are produced by man in virtue of his own nature. Therefore the generation by which such dispositions are introduced into matter, through whose mediation the union of the soul with matter takes place, is natural and not supernatural. — And when the consequence is argued on the ground that no natural form would be introduced, the consequence is denied. For although the soul is not natural from the fact that it exists in the natural potency of matter, it is nevertheless natural because it is naturally inclined to union with matter.

3. To the second it is said first that man must indeed subsist per se, just as the soul does, since he performs certain operations first and per se, just as the soul understands and wills per se. Yet it is not necessary that esse belong to man in that first and per se way in which it belongs to the soul.

Therefore it is said in the second place that esse can be understood to belong to something first and per se in two ways. In one way, insofar as "first" excludes absolutely any receiver of esse to which esse belongs formally prior. And thus, for something to belong first and per se to a thing is for that thing to have esse, and not through something else to which that esse belongs prior. — In the other way, so as to exclude not just any being existing prior by that esse, but only a being existing as this something and as a supposit. And thus, for esse to belong to something first and per se is to have esse, and not through another thing to which it belongs prior, as to a supposit existing per se.

In the first way, esse belongs to the intellectual soul first and per se, because it belongs to it before it belongs to any absolutely existing thing: for we first understand the soul itself to come into being through creation and to have esse, and only afterwards do we understand that esse to be communicated to matter and to the composite through the soul itself. Hence St. Thomas says in I Sentences, d. VIII, q. v, a. 2, ad 2, that the soul has in itself perfect esse, and that this very esse which is the soul's per se becomes the esse of the composite; and ad 8 ¹⁵ he says that to come into being is properly owed to the intellectual soul, and that the body is drawn to its esse. Likewise, in On Spiritual Creatures, art. 2, ad 3, he says that the soul has subsistent esse elevated above matter, and that the body is received into the communion of this esse, so that there is one esse of soul and body, which is the esse of man. In this, as was said above ¹⁶, it differs from a material form: because esse does not belong to a material form before it belongs to the composite; but just as the composite is that which properly comes into being, while the form does not properly come into being but is that by which something comes into being, so the composite is that which first and properly is, whereas the form is that by which it is, not that which is, except improperly.

In the second way, esse belongs first and per se to the composite, namely to man: for although it belongs to the soul prior in order, it does not belong to it as a supposit, but as a form which is a part of man, even though its esse is not dependent on matter.

To the doubt, therefore, it is said that the argument concludes truly, taking "first and per se" in the second way. For just as the operations of the vegetative and sensitive part belong first and per se to the composite as the supposit of the agent, so esse belongs first and per se to it as the supposit. This, however, is not repugnant to what we said above, namely that esse, I say, belongs first and per se to the soul: for we understood that of the first and per se in the first way; for thus esse can belong first and per se to a form not immersed in matter, such as the intellective soul is.

VII. As to the third ¹⁷, a reply must be given to the objections of Scotus ¹⁸. To the first, the antecedent is denied. For we have already said ¹⁹ what is the mind of St. Thomas, and it is expressly stated in this very place that the esse of actual existence is one and the same for the form, for the matter, and for the composite.

2. For the solution of the second, two distinctions must be noted. The first is that we can speak of esse in two ways: namely, insofar as it names the essence of a thing, in which way it is said to signify the definition, that which a thing is, as the esse of the thing; and insofar as it names actual existence. — The second is that the intellective soul, since it is the form of the body and has the power of understanding, can be considered in two ways: namely, insofar as it is the form of the body, and insofar as it is intellect or intellective. Insofar as it is the form of the body, it concurs with the body as a part in the constitution of the specific nature; insofar as it is intellective, it transcends the capacity of matter. Hence its perfection simply speaking is insofar as it pertains to the specific nature, since it is essentially a part of the species; but its perfection in a certain respect is according to the power of understanding, because essential perfection is prior by nature to accidental perfection absolutely speaking.

To the argument, therefore, it is said first that this determination does not contradict the doctrine of Saint Thomas; rather, it is most conformable to it. For it is not contradictory that the state of the soul is more perfect in the body than outside the body, and that the esse of the soul and that of man are one and the same.

It is said in reply to the second argument, speaking of esse of actual existence, that the major premise is false. For a thing can have many imperfections from the fact that it does not communicate its esse to another. The first imperfection is according to the nature of the species. For if a thing is by its nature part of a species, when it is separated from the whole it lacks the integrity of its specific nature. For no part separated from the whole has the perfection of nature ²⁰: since the whole is related to all its parts as form to matter, if a part is separated from the whole, it will not be under its natural and specific form, and consequently it will not be perfect according to specific perfection. This is how St. Thomas understands the soul to be less perfect when separated from the body than in the body: as is clear from IV Sent., where above ²¹, and d. XLIX, q. I, a. 4 ²²; and in the First Part, q. LXXXIX, a. 2, ad 1; and Spiritual. Creaturis, a. 2, ad 5; and de Anima, a. 17, ad 1. — The second imperfection is according to likeness to God. For, as is stated in Potentia, q. v, 10, ad 5, and in Book IV, d. XLIII, q. 1, a. 1, quª 1, ad 4, each thing is more simply like God the more it has of what the condition of its nature requires: just as a heart in motion is more like the unmoving God than one at rest. Hence what is by its nature part of a species, and is ordered to the formal communication of its esse—as is the intellective soul—if it does not communicate its esse and is not actually a part, is not perfectly assimilated to God. — The third imperfection is according to causality. For, as is said in Spiritualibus Creaturis, where above, nothing is perfect in its nature unless what is contained in it virtually can be brought into act. Hence the separated soul is imperfect according to nature: because the organic powers cannot flow from it, which are meant to flow from it insofar as it can inform matter. — It is therefore evident that for many reasons that major premise is false. To the proof it is said that certainly perfection is presupposed to communicating: yet not every perfection of a thing, nor every mode of perfection, is presupposed to that communication. And so there is presupposed to that communication the perfection of the soul which is according to its proper entity, but not the other perfections meant to belong to it.

It is said thirdly, in reply to the minor, that Saint Thomas understands this of the esse of actual existence, not of essential esse, which is specific esse. For a separated soul and a conjoined soul do not have the same complete specific essence: since, when the soul is separated from the body, the essence of the whole does not remain, which in a certain way informed the soul when conjoined.

It is said in the fourth place, for fuller explanation, from the doctrine of Saint Thomas in the places cited above, that although the soul united to the body is more perfect insofar as it is a form and with respect to its specific nature, yet insofar as it is intellect, and with respect to the act of understanding, it is more perfect when separated: because understanding belongs to it as it is raised above matter; hence understanding does not take place through any bodily organ. — This, however, must be understood of separation from a corruptible body, as is said in Book IV, d. 49, where it was treated above: for such a body, since it is not perfectly perfected by the soul, has something that resists the soul's action and impedes it. But if there be removed from the body that by which it resists the soul's action, as happens in a glorified body, then the soul, with respect to its power of understanding, is more perfect in the body than when separated: because then it is also more perfect in its own nature; and the more perfect something is in its own nature, the more perfectly can it act — provided all impediments are removed. I say this because it may stand that something is more perfect absolutely according to nature, and yet cannot act more perfectly, because impediments are conjoined to that perfection. Hence the soul in a corruptible body, although it is more perfect according to nature, nevertheless does not perform the works of the intellect more perfectly, because the corruptible body has something that impedes the soul's action.

3. To the third it is said that the soul is less perfect than man in being, as regards quidditative and essential esse, as was said ²³; but not as regards the esse of existence, which we said ²⁴ is one for the soul and for man—unless perhaps as regards the mode of having it, inasmuch as man has it in the manner of a supposit, while the soul has it in the manner of a form not dependent on matter. Hence, speaking of the esse of existence, the falsity of the consequent is denied. — But if the consequent be understood of quidditative esse, the consequence is denied. And to the proof, the assumption is denied: for things having the same esse of existence are not equal in quidditative being.

4. To the fourth it is said that the esse of existence of the composite can be considered in two ways: namely, absolutely; and as it is the composite's. If it is taken in the first way, the antecedent is denied as to its first part. For the esse of a composite is not corrupted, even though its essence be corrupted, but remains in the separated soul. — If it is taken in the second way, the consequence is denied. For the esse of the soul, which was also the esse of the composite, can cease to actualize the composite, and yet remain one and the same in the separated soul.

VIII. The third argument of Saint Thomas ²⁵ is this. It is always found that the lowest member of a higher order touches upon the highest of a lower genus: as is the teaching of Dionysius, Chapter VII of the Divine Names; and this is also evident by way of example in oysters, which, though they are lowest in the genus of animals, exceed but little the life of plants. But the soul is the lowest in the genus of intellectual substances: as can be perceived from its mode of understanding. Therefore there must be taken something in the genus of bodies, namely the human body, equally tempered in its complexion, like the heavens insofar as it is removed from contraries, which reaches up to the intellective soul.

It is confirmed by what is said in the Book of Causes: the soul is a certain horizon and boundary of corporeal and incorporeal things, inasmuch as it is an incorporeal form, and yet it is the form of a body.

It must be noted that this argument does not prove with necessity, because someone could say that, although the lowest of the higher order touches the highest of the lower, it does not follow that it must be its form; rather, it is a kind of persuasion. Hence, in order to intimate this, he proposed that in this the marvelous interconnection of things can be considered. For this manner of speaking gives us to understand that, given that the intellectual soul is the form of the body, a certain congruity and fittingness can be assigned to it. This is shown most clearly from the Quaestio de Spiritualibus Creaturis, article 6, where Saint Thomas, responding to the first argument—by which it was argued, through the proposition of Dionysius, that the heavenly body must be animate because it is the highest body, while the intellectual soul is the lowest in spiritual nature—says that the heavenly body attains to spiritual substances insofar as the lowest order of spiritual substances is united to heavenly bodies by way of mover.

2. But because someone might hesitate over this conclusion, since it does not seem clear how one thing can be made from a spiritual substance and matter, he replies that from them no less is made one thing than from the form of fire and its matter. Indeed, perhaps more: because that form more thoroughly masters its matter. He speaks, however, in a doubtful manner, because it does not pertain to his purpose which of these should be said: namely, whether a greater unity is made from them, or whether it is not made greater. — How, however, a greater unity can be made from soul and matter was shown above in Book I, chapter XVIII, in the fifth argument ²⁶.

3. Concerning this third argument a doubt is raised. For if the intellective soul is fittingly united to the body as its form because the lowest of the higher order touches the highest of the lower, it seems that the soul ought to have been united to a heavenly body, since that is the highest among bodies, and not to a body composed of the elements, such as the human body is.

It is answered that the lowest of the higher order must be united to the highest of the lower, namely either the highest simply, or the highest among those things of the lower order that are naturally suited to serve the higher. Now, as is stated in the Questions on the Soul, article 8, a celestial body is not fit to serve the intellectual soul, but a mixed body: because, since the intellectual soul, being the lowest in the genus of intellectual beings, is not united to a body except so as to acquire knowledge of the truth through the senses, it was necessary for it to be united to a body that would be a suitable organ of touch, in which all the other senses are grounded; and such a body must be a mixed body, as is clear from the Book on the Soul ²⁷.

IX. As to the second point ²⁸, Saint Thomas shows how the intellective soul, although it is united to matter, is nevertheless not wholly immersed in it, nor comprehended by it. In regard to this he does two things: first, he establishes the proposition; second, he excludes a certain objection ²⁹.

First he proves it by the following argument. The intellective soul has an operation in which it does not share with matter. Therefore it is not wholly comprehended within matter. — The antecedent is evident, because understanding does not come about through a bodily organ. — But the consequence is proved, because a form whose operation exceeds the condition of matter exceeds matter itself according to the dignity of its esse: since each thing acts according as it is. This is made manifest by running through the grades of forms, namely of the element, the mixed body, plants, brute animals, and man, in which it is shown that the nobler a form is, the more it is able to rise to higher operations above the conditions of matter.

For the greater clarity of this conclusion, it must be considered that Saint Thomas takes as equivalent that a form is not immersed in matter, that a form is not totally comprehended by matter, and that matter does not equal the esse of the form. For that form is said to be immersed in matter, as is stated in Quaestio de Spiritualibus Creaturis, article 2, whose esse is bound to matter and dependent upon it, namely because it cannot be except in matter. It is also said to be totally comprehended by matter, because in no way can it go beyond matter, that is, so as to exist without matter. And likewise matter is said to equal the esse of the form when it receives the whole perfection of the form's esse, such that outside matter that form cannot be: for if the form can have esse outside matter, then matter no longer equals that esse. Now through all expressions of this kind it is evident that the same thing is meant. Hence, since the intellectual soul, which communicates its esse to matter by raising it to a higher order, can in some way have esse outside matter—as is plainly clear from its operation—it must be said that it is not immersed in matter, nor equal to it with respect to esse, nor totally comprehended by it.

Concerning that gradation of forms set forth here, it must be noted that they are graded, to speak summarily, in such a way that the forms of the elements can extend only to the operations of the material qualities, active and passive: such as heating, cooling, descent, ascent, and the like. — The forms of mixtures can sometimes extend to certain effects which can be accomplished through the aforesaid qualities, but they accomplish these by a higher power derived from the heavenly bodies, consequent upon their species: as the magnet, or even the adamant, draws iron, and the sapphire cures an abscess. — The forms of plants can extend also to effects into which the aforesaid qualities cannot enter, yet for those effects they use those very qualities as instruments: as is evident in nourishing and growing up to a determinate limit. And further, they are assimilated to the movers of the heavenly bodies in moving, insofar as they are the principle of motion for things that move themselves. — The souls of brutes extend further to the operation of sense, which exceeds the aforesaid qualities, and to this they do not operate even instrumentally: although they are necessary for the due disposition of the organ. — But the intellective soul extends to the intellective operation, to which, on the part of the one understanding, material qualities contribute in no way, neither as instruments nor as dispositions of the organ: since it is not brought about through a bodily organ.

X. But concerning the foregoing, two doubts arise. The first pertains to man, concerning the form of the mixed body. For here Saint Thomas says that the form of the mixed body, namely of the inanimate, cannot extend itself to certain operations which cannot be accomplished through material qualities, although at times they produce those effects by a higher power. Yet in the First Part, q. 76, a. 1, and in the Quaestio de Spiritualibus Creaturis, art. 2, he holds that the form of the mixed body has some operation exceeding the active and passive qualities.

2. The second doubt concerns the operation of the intellective soul. For Saint Thomas seems to hold that understanding belongs to it insofar as it exceeds the condition of matter, since in that operation the matter of the body does not take part. Against this Scotus argues, in his Quodlibet, question IX ³⁰, in two ways. First: Man is not man through the soul except as it informs matter. Therefore neither does he perform an operation proper to man through the soul, except as the soul informs matter. Therefore either it does not understand through the soul as through a form that is the principle of this operation; or it understands through it as informing matter. — The antecedent is proved: because the composite is only what it is from its united parts, as is clear from Metaphysics VII ³¹.

Second. The soul informs matter according to the highest degree of its essential perfection. But understanding cannot belong to it according to any degree higher than the highest. Therefore it does not belong to it insofar as it exceeds matter: understanding by "exceed" not informing.

XI. To the first doubt it can be answered that we can speak in two ways of that effect of the form of a mixed body: in one way, with respect to the species of the effect; in another way, with respect to the mode of producing it. In the first way St. Thomas speaks here; in the second way, however, in other places. For although any effect of the form of an inanimate mixed body can be reached by the power of material qualities, it is nevertheless not reached in that manner: because the form of a mixed body produces some effect by a more noble power than the power of those qualities, namely by a power consequent upon the species from the influence of the heavenly body; and consequently it also produces it in a higher and more noble manner.

2. To the second doubt it is said that Saint Thomas does not understand the intellective soul to exceed matter as not informing matter, as appears from what was said above in this chapter; but rather that it is not immersed in matter, bound to matter, and wholly comprehended by it, inasmuch as it depends on matter in such a way that it could not have esse outside matter. Hence, for the act of understanding to belong to the soul insofar as it exceeds the condition of matter is not for that operation to belong to the soul insofar as it does not inform matter, but insofar as it has an esse so elevated above matter that it neither depends on it nor is comprehended by it. And a sign of this is that that operation takes place without a bodily organ.

For that reason, Scotus's arguments are not against the mind of Saint Thomas, but proceed from a poor understanding of his words. Nevertheless, a reply is given to them in particular.

To the first, it is said that man indeed does not act by an operation proper to himself, nor through the soul, unless that soul inform matter; and yet understanding does not belong to him insofar as he informs, if "insofar as" is taken to signify the reason of understanding, but rather insofar as he so informs matter that he does not depend on it according to esse—which is to exceed matter. For as St. Thomas says in the Quaestio de Anima, art. 14, ad 10: although the soul by its essence is a form, nevertheless something can belong to it insofar as it is such a form, namely a subsistent form, which does not belong to it insofar as it is a form—just as understanding does not belong to man insofar as he is an animal, although man is an animal by his essence.

To the second it is said that the soul, according to its highest essential grade, certainly informs matter; but it is not immersed in matter—rather, it remains subsisting in itself and not dependent on matter with respect to its esse; and this is what it means for the soul to exceed matter. And this is the reason why it can understand. This reason, because in material forms it is not found—for they are immersed in matter and do not subsist in themselves—they cannot understand.

XII. As to the second point of this part ³²: since someone might suppose that, because the intellectual soul does not depend on matter but is subsistent in itself, its union with matter is therefore not natural, Saint Thomas replies that, notwithstanding this, that union is natural. He proves it by this argument. A form that needs for its operation powers acting through bodily organs is naturally united to a body. The intellectual soul is of this kind, for it needs imagination and sense, namely exterior sense. Therefore it is naturally united to the body so as to complete the human species.

To make this argument evident, it must be considered that it befits the nature of each thing to have what is necessary for its proper operation, since every thing exists for the sake of its own operation and is naturally inclined toward it. Now for the proper operation of the intellectual soul—because it is lowest in the genus of intellectual things, just as prime matter is in the genus of sensible things, and therefore does not possess intelligible species by its own nature—it is required that it be brought into act through intelligible species, acquiring them through the sensitive powers from sensible things, as is said in Qu. de Anima, art. 7. But this cannot happen unless the soul is united to a body of due complexion, since the operation of sense occurs only through a bodily organ. Therefore it belongs to the soul by nature that it be united to a body. And this is the foundation of the argument.

XIII. But a doubt arises. For what belongs to something naturally cannot be separated from it: for everything of this kind belongs to a thing according to itself. Therefore, if to be united to a body is natural to the soul, the soul can never be ununited to a body. And consequently, when the body is corrupted, the soul itself must also be corrupted.

2. It can be answered first that the major premise is true speaking per se; but what is per se can be separated per accidens, when something that belongs to a thing naturally belongs to it in relation to some extrinsic factor; just as being upward naturally befits the light, yet it can be impeded from being upward.

It is answered to the second argument that something can be said to be natural to a thing in two ways: in one way, by way of a first act, as risibility is natural to man; in another way, by way of a second act, or of the terminus of a second act, to the thing to which it is said to be natural, just as laughing is natural to man. What is natural in the first way cannot be separated, because such a thing is either essential or follows from the essential principles of the species, or from the principles of the individual. But what is natural in the second way can be separated in some things according to act, though not according to natural aptitude; for although nature has an inclination toward it, it need not always be present in reality, either because of supervening impediments or for other causes. — Therefore, in the matter at hand, union with matter is natural to the intellectual soul in the second way, but not in the first. For the soul's being united to matter is its drawing matter into participation in its esse, so that we first understand the soul to subsist in its esse, and then to communicate that esse to matter. Hence St. Thomas says in the First Part, q. 76, a. 1, ad 6, that to be united to the body belongs to the soul in itself, just as to be upward belongs to the light body in itself; but it is clear that to be upward belongs to the light body by way of a second act, or of the terminus of a second act, since it is an effect of lightness, which moves toward the place above. Therefore the soul can fail to be united to the body, although, when separated from the body, it retains its aptitude and natural inclination to union with the body, just as a light body can fail to be upward and yet always has aptitude and inclination toward the place above. — From these things it is evident how the objection is met. For the major premise is false concerning what is natural in the second way, and only in this sense does the minor have truth. — And to the proof offered for it, the reply is made in the same manner: that the assumption holds true of what belongs to a thing in itself by way of a first act, but not of what belongs to a thing by way of a second act. The reason for this is that such a thing is not said per se principally, but only reductively, insofar as it is the act of that which belongs to the thing per se.

It can be answered in a third way, according to the mind of Saint Thomas in the Treatise on Being and Essence, last chapter, that something can be said to be natural to a thing in two ways: one way, because it is caused by its nature in perfect act, as heat is natural to fire; another way, because it is caused by the principles of the nature only in aptitude, but receives its completion from without, as transparency is natural to air, yet is completed by an external luminous body. What is natural in the first way is simply inseparable from the thing: