Summa Theologica Part I (Prima Pars) Part 118

Obj. 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 partic.i.p.ation 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 Obj. 1: As the power of the soul flows from the essence, not by a trans.m.u.tation, but by a certain natural resultance, and is simultaneous with the soul, so is it the case with one power as regards another.

Reply Obj. 2: An accident cannot of itself be the subject of an accident; but one accident is received prior to another into substance, as quant.i.ty 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 Obj. 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.

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EIGHTH ARTICLE [I, Q. 77, Art. 8]

Whether All the Powers Remain in the Soul When Separated from the Body?

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."

Obj. 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.

Obj. 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.

Obj. 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 h.e.l.l: "Remember that thou didst receive good things during thy lifetime" (Luke 16:25). Therefore memory remains in the separated soul; and consequently the other powers of the sensitive part.

Obj. 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.

Obj. 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. 5, 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 Obj. 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 Obj. 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 Obj. 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 Obj. 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 Obj. 5: In the separate soul, sorrow and joy are not in the sensitive, but in the intellectual appet.i.te, as in the angels.

Reply Obj. 6: Augustine in that pa.s.sage is speaking as inquiring, not as a.s.serting. Wherefore he retracted some things which he had said there (Retrac. ii, 24).

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QUESTION 78

OF THE SPECIFIC POWERS OF THE SOUL (In Four Articles)

We next treat of the powers of the soul specifically. The theologian, however, has only to inquire specifically concerning the intellectual and appet.i.tive powers, in which the virtues reside. And since the knowledge of these powers depends to a certain extent on the other powers, our consideration of the powers of the soul taken specifically will be divided into three parts: first, we shall consider those powers which are a preamble to the intellect; secondly, the intellectual powers; thirdly, the appet.i.tive powers.

Under the first head there are four points of inquiry:

(1) The powers of the soul considered generally;

(2) The various species of the vegetative part;

(3) The exterior senses;

(4) The interior senses.

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FIRST ARTICLE [I, Q. 78, Art. 1]

Whether There Are to Be Distinguished Five Genera of Powers in the Soul?

Objection 1: It would seem that there are not to be distinguished five genera of powers in the soul--namely, vegetative, sensitive, appet.i.tive, locomotive, and intellectual. For the powers of the soul are called its parts. But only three parts of the soul are commonly a.s.signed--namely, the vegetative soul, the sensitive soul, and the rational soul. Therefore there are only three genera of powers in the soul, and not five.

Obj. 2: Further, the powers of the soul are the principles of its vital operations. Now, in four ways is a thing said to live. For the Philosopher says (De Anima ii, 2): "In several ways a thing is said to live, and even if only one of these is present, the thing is said to live; as intellect and sense, local movement and rest, and lastly, movement of decrease and increase due to nourishment." Therefore there are only four genera of powers of the soul, as the appet.i.tive is excluded.

Obj. 3: Further, a special kind of soul ought not to be a.s.signed as regards what is common to all the powers. Now desire is common to each power of the soul. For sight desires an appropriate visible object; whence we read (Ecclus. 40:22): "The eye desireth favor and beauty, but more than these green sown fields." In the same way every other power desires its appropriate object. Therefore the appet.i.tive power should not be made a special genus of the powers of the soul.

Obj. 4: Further, the moving principle in animals is sense, intellect or appet.i.te, as the Philosopher says (De Anima iii, 10).

Therefore the motive power should not be added to the above as a special genus of soul.

_On the contrary,_ The Philosopher says (De Anima ii, 3), "The powers are the vegetative, the sensitive, the appet.i.tive, the locomotion, and the intellectual."

_I answer that,_ There are five genera of powers of the soul, as above numbered. Of these, three are called souls, and four are called modes of living. The reason of this diversity lies in the various souls being distinguished accordingly as the operation of the soul transcends the operation of the corporeal nature in various ways; for the whole corporeal nature is subject to the soul, and is related to it as its matter and instrument. There exists, therefore, an operation of the soul which so far exceeds the corporeal nature that it is not even performed by any corporeal organ; and such is the operation of the _rational soul._ Below this, there is another operation of the soul, which is indeed performed through a corporeal organ, but not through a corporeal quality, and this is the operation of the _sensitive soul;_ for though hot and cold, wet and dry, and other such corporeal qualities are required for the work of the senses, yet they are not required in such a way that the operation of the senses takes place by virtue of such qualities; but only for the proper disposition of the organ. The lowest of the operations of the soul is that which is performed by a corporeal organ, and by virtue of a corporeal quality. Yet this transcends the operation of the corporeal nature; because the movements of bodies are caused by an extrinsic principle, while these operations are from an intrinsic principle; for this is common to all the operations of the soul; since every animate thing, in some way, moves itself. Such is the operation of the _vegetative soul;_ for digestion, and what follows, is caused instrumentally by the action of heat, as the Philosopher says (De Anima ii, 4).

Now the powers of the soul are distinguished generically by their objects. For the higher a power is, the more universal is the object to which it extends, as we have said above (Q. 77, A. 3, ad 4). But the object of the soul's operation may be considered in a triple order. For in the soul there is a power the object of which is only the body that is united to that soul; the powers of this genus are called "vegetative" for the vegetative power acts only on the body to which the soul is united. There is another genus in the powers of the soul, which genus regards a more universal object--namely, every sensible body, not only the body to which the soul is united. And there is yet another genus in the powers of the soul, which genus regards a still more universal object--namely, not only the sensible body, but all being in universal. Wherefore it is evident that the latter two genera of the soul's powers have an operation in regard not merely to that which is united to them, but also to something extrinsic. Now, since whatever operates must in some way be united to the object about which it operates, it follows of necessity that this something extrinsic, which is the object of the soul's operation, must be related to the soul in a twofold manner. First, inasmuch as this something extrinsic has a natural apt.i.tude to be united to the soul, and to be by its likeness in the soul. In this way there are two kinds of powers--namely, the "sensitive" in regard to the less common object--the sensible body; and the "intellectual," in regard to the most common object--universal being. Secondly, forasmuch as the soul itself has an inclination and tendency to the something extrinsic. And in this way there are again two kinds of powers in the soul: one--the "appet.i.tive"--in respect of which the soul is referred to something extrinsic as to an end, which is first in the intention; the other--the "locomotive" power--in respect of which the soul is referred to something extrinsic as to the term of its operation and movement; for every animal is moved for the purpose of realizing its desires and intentions.

The modes of living are distinguished according to the degrees of living things. There are some living things in which there exists only vegetative power, as the plants. There are others in which with the vegetative there exists also the sensitive, but not the locomotive power; such as immovable animals, as sh.e.l.lfish. There are others which besides this have locomotive powers, as perfect animals, which require many things for their life, and consequently movement to seek necessaries of life from a distance. And there are some living things which with these have intellectual power--namely, men. But the appet.i.tive power does not const.i.tute a degree of living things; because wherever there is sense there is also appet.i.te (De Anima ii, 3).

Thus the first two objections are hereby solved.

Reply Obj. 3: The "natural appet.i.te" is that inclination which each thing has, of its own nature, for something; wherefore by its natural appet.i.te each power desires something suitable to itself. But the "animal appet.i.te" results from the form apprehended; this sort of appet.i.te requires a special power of the soul--mere apprehension does not suffice. For a thing is desired as it exists in its own nature, whereas in the apprehensive power it exists not according to its own nature, but according to its likeness. Whence it is clear that sight desires naturally a visible object for the purpose of its act only--namely, for the purpose of seeing; but the animal by the appet.i.tive power desires the thing seen, not merely for the purpose of seeing it, but also for other purposes. But if the soul did not require things perceived by the senses, except on account of the actions of the senses, that is, for the purpose of sensing them; there would be no need for a special genus of appet.i.tive powers, since the natural appet.i.te of the powers would suffice.

Reply Obj. 4: Although sense and appet.i.te are principles of movement in perfect animals, yet sense and appet.i.te, as such, are not sufficient to cause movement, unless another power be added to them; for immovable animals have sense and appet.i.te, and yet they have not the power of motion. Now this motive power is not only in the appet.i.te and sense as commanding the movement, but also in the parts of the body, to make them obey the appet.i.te of the soul which moves them. Of this we have a sign in the fact that when the members are deprived of their natural disposition, they do not move in obedience to the appet.i.te.

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SECOND ARTICLE [I, Q. 78, Art. 2]

Whether the Parts of the Vegetative Soul Are Fittingly Described As the Nutritive, Augmentative, and Generative?