Summa Theologica

Objection 1: It would seem that the powers of the soul do not flow from its essence. For different things do not proceed from one simple thing. But the essence of the soul is one and simple. Since, therefore, the powers of the soul are many and various, they cannot proceed from its essence.

Objection 2: Further, that from which a thing proceeds is its cause. But the essence of the soul cannot be said to be the cause of the powers; as is clear if one considers the different kinds of causes. Therefore the powers of the soul do not flow from its essence.

Objection 3: Further, emanation involves some sort of movement. But nothing is moved by itself, as the Philosopher proves (Phys. vii, 1,2); except, perhaps, by reason of a part of itself, as an animal is said to be moved by itself, because one part thereof moves and another is moved. Neither is the soul moved, as the Philosopher proves (De Anima i, 4). Therefore the soul does not produce its powers within itself.

On the contrary, The powers of the soul are its natural properties. But the subject is the cause of its proper accidents; whence also it is included in the definition of accident, as is clear from Metaph. vii (Did. vi, 4). Therefore the powers of the soul proceed from its essence as their cause.

I answer that, The substantial and the accidental form partly agree and partly differ. They agree in this, that each is an act; and that by each of them something is after a manner actual. They differ, however, in two respects. First, because the substantial form makes a thing to exist absolutely, and its subject is something purely potential. But the accidental form does not make a thing to exist absolutely but to be such, or so great, or in some particular condition; for its subject is an actual being. Hence it is clear that actuality is observed in the substantial form prior to its being observed in the subject: and since that which is first in a genus is the cause in that genus, the substantial form causes existence in its subject. On the other hand, actuality is observed in the subject of the accidental form prior to its being observed in the accidental form; wherefore the actuality of the accidental form is caused by the actuality of the subject. So the subject, forasmuch as it is in potentiality, is receptive of the accidental form: but forasmuch as it is in act, it produces it. This I say of the proper and "per se" accident; for with regard to the extraneous accident, the subject is receptive only, the accident being caused by an extrinsic agent. Secondly, substantial and accidental forms differ, because, since that which is the less principal exists for the sake of that which is the more principal, matter therefore exists on account of the substantial form; while on the contrary, the accidental form exists on account of the completeness of the subject.

Now it is clear, from what has been said(A[5]), that either the subject of the soul's powers is the soul itself alone, which can be the subject of an accident, forasmuch as it has something of potentiality, as we have said above (A[1], ad 6); or else this subject is the composite. Now the composite is actual by the soul. Whence it is clear that all the powers of the soul, whether their subject be the soul alone, or the composite, flow from the essence of the soul, as from their principle; because it has already been said that the accident is caused by the subject according as it is actual, and is received into it according as it is in potentiality.

Reply to Objection 1: From one simple thing many things may proceed naturally, in a certain order; or again if there be diversity of recipients. Thus, from the one essence of the soul many and various powers proceed; both because order exists among these powers; and also by reason of the diversity of the corporeal organs.

Reply to Objection 2: The subject is both the final cause, and in a way the active cause, of its proper accident. It is also as it were the material cause, inasmuch as it is receptive of the accident. From this we may gather that the essence of the soul is the cause of all its powers, as their end, and as their active principle; and of some as receptive thereof.

Reply to Objection 3: The emanation of proper accidents from their subject is not by way of transmutation, but by a certain natural resultance; thus one thing results naturally from another, as color from light.

Objection 1: It would seem that one power of the soul does not arise from another. For if several things arise together, one of them does not arise from another. But all the powers of the soul are created at the same time with the soul. Therefore one of them does not arise from another.

Objection 2: Further, the power of the soul arises from the soul as an accident from the subject. But one power of the soul cannot be the subject of another; because nothing is the accident of an accident. Therefore one power does not arise from another.

Objection 3: Further, one opposite does not arise from the other opposite; but everything arises from that which is like it in species. Now the powers of the soul are oppositely divided, as various species. Therefore one of them does not proceed from another.

On the contrary, Powers are known by their actions. But the action of one power is caused by the action of another power, as the action of the imagination by the action of the senses. Therefore one power of the soul is caused by another.

I answer that, In those things which proceed from one according to a natural order, as the first is the cause of all, so that which is nearer to the first is, in a way, the cause of those which are more remote. Now it has been shown above(A[4]) that among the powers of the soul there are several kinds of order. Therefore one power of the soul proceeds from the essence of the soul by the medium of another. But since the essence of the soul is compared to the powers both as a principle active and final, and as a receptive principle, either separately by itself, or together with the body; and since the agent and the end are more perfect, while the receptive principle, as such, is less perfect; it follows that those powers of the soul which precede the others, in the order of perfection and nature, are the principles of the others, after the manner of the end and active principle. For we see that the senses are for the sake of the intelligence, and not the other way about. The senses, moreover, are a certain imperfect participation of the intelligence; wherefore, according to their natural origin, they proceed from the intelligence as the imperfect from the perfect. But considered as receptive principles, the more perfect powers are principles with regard to the others; thus the soul, according as it has the sensitive power, is considered as the subject, and as something material with regard to the intelligence. On this account, the more imperfect powers precede the others in the order of generation, for the animal is generated before the man.

Reply to Objection 1: As the power of the soul flows from the essence, not by a transmutation, but by a certain natural resultance, and is simultaneous with the soul, so is it the case with one power as regards another.

Reply to Objection 2: An accident cannot of itself be the subject of an accident; but one accident is received prior to another into substance, as quantity prior to quality. In this sense one accident is said to be the subject of another; as surface is of color, inasmuch as substance receives an accident through the means of another. The same thing may be said of the powers of the soul.

Reply to Objection 3: The powers of the soul are opposed to one another, as perfect and imperfect; as also are the species of numbers and figures. But this opposition does not prevent the origin of one from another, because imperfect things naturally proceed from perfect things.

Objection 1: It would seem that all the powers of the soul remain in the soul separated from the body. For we read in the book De Spiritu et Anima that "the soul withdraws from the body, taking with itself sense and imagination, reason and intelligence, concupiscibility and irascibility."

Objection 2: Further, the powers of the soul are its natural properties. But properties are always in that to which they belong; and are never separated from it. Therefore the powers of the soul are in it even after death.

Objection 3: Further, the powers even of the sensitive soul are not weakened when the body becomes weak; because, as the Philosopher says (De Anima i, 4), "If an old man were given the eye of a young man, he would see even as well as a young man." But weakness is the road to corruption. Therefore the powers of the soul are not corrupted when the body is corrupted, but remain in the separated soul.

Objection 4: Further, memory is a power of the sensitive soul, as the Philosopher proves (De Memor. et Remin. 1). But memory remains in the separated soul; for it was said to the rich glutton whose soul was in hell: "Remember that thou didst receive good things during thy lifetime" (Lk. 16:25). Therefore memory remains in the separated soul; and consequently the other powers of the sensitive part.

Objection 5: Further, joy and sorrow are in the concupiscible part, which is a power of the sensitive soul. But it is clear that separate souls grieve or rejoice at the pains or rewards which they receive. Therefore the concupiscible power remains in the separate soul.

Objection 6: Further, Augustine says (Gen. ad lit. xii, 32) that, as the soul, when the body lies senseless, yet not quite dead, sees some things by imaginary vision; so also when by death the soul is quite separate from the body. But the imagination is a power of the sensitive part. Therefore the power of the sensitive part remains in the separate soul; and consequently all the other powers.

On the contrary, It is said (De Eccl. Dogm. xix) that "of two substances only does man consist; the soul with its reason, and the body with its senses." Therefore the body being dead, the sensitive powers do not remain.

I answer that, As we have said already (AA,6,7), all the powers of the soul belong to the soul alone as their principle. But some powers belong to the soul alone as their subject; as the intelligence and the will. These powers must remain in the soul, after the destruction of the body. But other powers are subjected in the composite; as all the powers of the sensitive and nutritive parts. Now accidents cannot remain after the destruction of the subject. Wherefore, the composite being destroyed, such powers do not remain actually; but they remain virtually in the soul, as in their principle or root.

So it is false that, as some say, these powers remain in the soul even after the corruption of the body. It is much more false that, as they say also, the acts of these powers remain in the separate soul; because these powers have no act apart from the corporeal organ.

Reply to Objection 1: That book has no authority, and so what is there written can be despised with the same facility as it was said; although we may say that the soul takes with itself these powers, not actually but virtually.

Reply to Objection 2: These powers, which we say do not actually remain in the separate soul, are not the properties of the soul alone, but of the composite.

Reply to Objection 3: These powers are said not to be weakened when the body becomes weak, because the soul remains unchangeable, and is the virtual principle of these powers.

Reply to Objection 4: The recollection spoken of there is to be taken in the same way as Augustine (De Trin. x, 11; xiv, 7) places memory in the mind; not as a part of the sensitive soul.

Reply to Objection 5: In the separate soul, sorrow and joy are not in the sensitive, but in the intellectual appetite, as in the angels.

Reply to Objection 6: Augustine in that passage is speaking as inquiring, not as asserting. Wherefore he retracted some things which he had said there (Retrac. ii, 24).