Summa contra Gentiles2.60 Chapter LX. That man derives his species n'ot from the passive, but from the possible intellect

To these arguments there is a reply on the lines of the foregoing opinion. For the said Averroes maintains that man differs in species from brutes by the intellect which Aristotle calls passive, which is the same as the cogitative power that is proper to man, in place of which other animals have a certain natural estimative power. And it belongs to this cogitative power to distinguish individual intentions and to compare them with one another: just as the intellect which is separate and unmixed compares and distinguishes universal intentions. And since by this power, together with the imagination and memory, the phantasms are prepared to receive the addition of the active intellect, whereby they are made actually intelligible—just as certain arts prepare the matter for the master craftsman—therefore the aforesaid power is called by the name of intellect or reason, which physicians declare to be seated in the middle cell of the head. And according to the disposition of this power, one man differs from another in genius and other points pertaining to intelligence. Also by the use and practice thereof man acquires the habit of science: so that the habits of science are in this passive intellect as their subject. Moreover this passive intellect is in the child from the beginning, and through it the child receives its human species before understanding actually.

But it is easy to see that all this is untrue and an abuse of terms. For vital operations are compared to the soul, as second acts to the first, as Aristotle declares in 2 De Anima, Now in the one subject first act precedes the second in point of time, just as knowledge precedes consideration. Hence in whatever thing we find a vital operation, we must place some part of the soul that will be compared to that operation as first to second act. Now man above other animals has a proper operation, namely intelligence and reasoning, which is the operation of man, as man, as Aristotle states (i Ethic.)} Therefore we must place in man a principle that properly gives him his species, and is compared to the act of intelligence as first to second act. But this cannot be the aforesaid passive intellect, since the principle of this same operation must needs be impassible and not mixed with the body, as the Philosopher proves, whereas it is clearly the contrary with the passive intellect. Therefore it is not possible that the species whereby man differs from other animals, should come to him through the cogitative power that is called the passive intellect.

Again. That which is a passion of the sensitive part cannot place a thing in a higher kind of life than the sensitive life: just as that which is a passion of the nutritive soul, does not place a thing in a higher kind of life than the nutritive. Now it is clear that the imagination and the like powers which are consequent upon it, such as the memory and so forth, are passions of the sensitive faculty, as the Philosopher proves in his book De Memoria. Consequently an animal cannot be placed by these powers or by any one of them, in a higher kind of life than the sensitive. But man is in a higher kind of life, as is proved from the Philosopher (2 De Anima),' who in distinguishing the kinds of life, places the intellective which he ascribes to man, above the sensitive which he ascribes to all animals in common. Therefore it is not through the aforesaid cogitative power that man is a living being with a life proper to himself.

Moreover. Every self-mover, as the Philosopher proves (8 Phys.), is composed of mover and moved. Now man, like the animals, is a self-mover. Therefore mover and moved are parts of him. But the first mover in man is the intellect, for the intellect by its intelligible object moves the will. Nor can it be said that the passive intellect alone is the mover, since the passive intellect is only of particulars, while in moving there comes into play both the universal opinion which belongs to the possible intellect, and the particular statement which may belong to the passive intellect, as we gather from Aristotle (3 De Anima, and 7 Ethic.). Therefore the possible intellect is a part of man: and is the most noble and most formal thing in him: and consequently he takes his species from it and not from the passive intellect.

Further. The possible intellect is proved not to be the act of a body from the fact of its taking cognizance of all sensible forms in the universal. Therefore no power, the operation of which can extend to the universals of all sensible forms, can be the act of a body. Now such is the will: since our will can extend to all the things that we can understand, at least so that we will to know them. Moreover the act of the will is clearly directed to the universal: since, as Aristotle says in his Rhetoric A we hate the rohber-kind in the universal, but are enraged only with the individuals. Consequently the will cannot be the act of a part of the body, nor can it be consequent upon a power that is an act of the body. Now any part of the soul is an act of the body, except the intellect alone properly so called. Hence the will is in the intellective part, wherefore also Aristotle says (3 De AnimaY that the will is in the reason, but the irascible and concupiscible are in the sensitive part. On account of this the acts of the concupiscible and irascible are associated with passion; whereas the act of the will is not, but with choice. Now man’s will is not outside man, as though it were vested in a separate substance, but is in man himself. Else he would not be master of his own actions, for he would be acted upon by the will of a separate substance: and in him there would only be the appetitive powers that operate with passion, namely the irascible and the concupiscible, which are in the sensitive part, as in other animals which are acted upon rather than act themselves. But this is impossible and would do away with all moral philosophy and social intercourse. Wherefore the possible intellect must be in us, so that we differ thereby from dumb animals, and not only by the passive intellect.

Again. Just as nothing is able (potens) to act except through an inherent active potentiality, so nothing is able to be passive except through an inherent passive potentiality: for the combustible is not only able to be burnt because there is something able to burn it, but also because it has in itself a potentiality to be burnt. Now to understand is a kind of passion, as stated in 3 De Animad Since then a child is potentially understanding, although he understands not actually, there must be in him a potentiality whereby he is able to understand: and this potentiality is the possible intellect. Consequently the possible intellect must already be in touch with the child before he understands actually. Therefore the contact of the possible intellect with man is not through the actually understood form; but the possible intellect itself is in a man from the beginning as a part of him.

The said Averroes replies to this argument. For he says that a child is said to be understanding potentially in two ways. First, because the phantasms in him are potentially intelligible; secondly, because the possible intellect is able (potens) to come in touch with him, and not because the intellect is already united to him.

Now we have to prove that either way is insufficient. For the potentiality by which the agent is able to act is distinct from the potentiality whereby the patient is able to be passive, and they differ as being opposite to one another. Consequently from the fact that a thing is able to be active, it is not competent to it to be passive. Now to be able to understand is to be able to be passive, since to understand is a kind of passion, according to the Philosopher. Therefore the child is not said to be able to understand, from the mere fact that the phantasms in him are able to be actually iv. 2. 2 Loc. cit. 3 C/. above.

understood, since this pertains to being able to act; for the phantasms move the possible intellect.

Again. A potentiality consequent on the species of a thing does not belong to it by reason of that which does not give that thing its species. Now ability to understand is consequent on the human species, for understanding is an operation of man as such. Whereas the phantasms do not give man his species, on the contrary they are consequent on his operation. Therefore the child cannot be said to be potentially understanding by reason of the phantasms.

Likewise, neither can a child be said to be potentially understanding, because the possible intellect is able to be in touch with him. For a person is said to be able to act or to be passive by active or passive potentiality, just as he is said to be white by whiteness. Now he is not said to be white before whiteness is united to him. Therefore neither is one said to be able to act or to be passive before the active or passive potentiality is in him. Consequently it cannot be said of a child that he is able to understand before the possible intellect, which is the power of understanding, is in touch with him.

Further. A person is said in one way to be able to act before having the nature whereby he acts, and in another way after he has the nature already, but is accidentally hindered from acting: even as a body is said in one way to be able to be lifted upwards before it is light, and in another way after it is made light, but is hindered in its movement. Now a child is potentially understanding, not as though he has not yet the nature to understand, but as having an obstacle to understanding, for he is hindered from understanding on account of the manifold movements in him, as stated in 7 Physic. Wherefore he is not said to be potentially understanding, on account of the possibility of coming in touch with the possible intellect which is the principle of understanding, but because it is already in touch with him and is hindered from its proper action; so that as soon as the obstacle is removed, he understands.

Again. A habit is that whereby one acts at will. Consequently a habit must be in the same subject as the operation that is according to that habit. But to consider by understanding, which is the act of the habit of science, - cannot be in the passive intellect, but belongs to the possible intellect, because in order that a power understand, it behoves it not to be the act of a body. Therefore the habit of science is not in the passive but in the possible intellect. Now science is in us, since according thereto we are said to know scientifically. Therefore the possible intellect also is in us, and has not a being separate from us.

Further. The assimilation of science is of the knower to the thing known. Now the knower is not assimilated to the thing known, as such, except in respect of universal species, for science is about such things. But universal species cannot be in the passive intellect,—since it is a power using an organ,—but only in the possible intellect. Therefore science is not in the passive, but only in the possible intellect.

Moreover. The intellect in habit, as the opponent admits, is the effect of the active intellect. Now the effects of the active intellect are things actually intelligible, the proper recipient of which is the possible intellect, to which the active intellect is compared as art to material, according to Aristotle (3 De Anima). Consequently the intellect in habit, which is the habit of science, must be in the possible, and not in the passive intellect.

Further. It is impossible that the perfection of a higher substance depend on a lower. Now the perfection of the possible intellect depends on the action of man, for it depends on the phantasms which move the possible intellect. Therefore the possible intellect is not a higher substance than man. Therefore it must be part of man as his act and form.

Again. Whatsoever things are separate as to being, are also separate as to operation, because things are for the sake of their operations, as first act for the sake of the Averroes, 3 De Anima, text 18.

second: wherefore Aristotle says (i De Anima), that if any operation of the soul is apart from the body, it is possible for the soul to be separated. Now the operation of the possible intellect requires the body: for the Philosopher says (3 De AnimaY that the intellect can act by itself, that is it can understand, when it has been made actual by a species abstracted from phantasms, which are not apart from the body. Therefore the possible intellect is not altogether separate from the body.

Moreover. A thing has by nature those attributes without which its connatural operation cannot be accomplished: thus Aristotle proves {2 De CoeloY that if the movement of the stars were progressive like that of animals, nature would have given them the organs of progressive movement. Now the operation of the possible intellect is accomplished through corporeal organs, which are necessary as subjects of the phantasms. Therefore nature has united the possible intellect to corporeal organs: and consequently it has not a being separate from the body.

Again. If it had a being separate from the body, it would understand substances that are separate from matter rather than sensible forms, for they are more intelligible, and more conformed to the intellect. Yet it cannot understand substances that are altogether separate from matter, since there are no phantasms of them: whereas this intellect nowise understands without phantasms, as Aristotle says (3 De Anima) f because the phantasms are to it as sensibles to the senses, and without these the sense has no sensation. Therefore it is not a substance separate from the body in being.

Further. In every genus the passive potentiality extends as far as the active potentiality of that genus; wherefore there is not in nature a passive potentiality, to which there does not correspond a natural active potentiality. But the active intellect makes only the phantasms to be intelligible. Therefore neither is the passive intellect moved by other intelligibles than the species abstracted from the phantasms; and thus it is unable to understand separate substances.

Moreover. The species of sensible things are in separate substances intelligibly, and by those species they have knowledge of sensibles. If therefore the possible intellect understood separate substances, it would receive in them the knowledge of sensibles. Consequently it would not receive this knowledge from phantasms, since nature's abundance does not consist of superfluities.

If, however, it be said that separate substances have no knowledge of sensibles, it must at least be granted that they have a higher knowledge. And this knowledge must not be lacking to the possible intellect, if it understands the said substances. Consequently it will have a twofold knowledge: one after the manner of separate substances, the other received from the senses: one of which would be superfluous.

Further. It is the possible intellect whereby the soul understands, as stated in 3 De Anima. If therefore the possible intellect understands separate substances, we also understand them. Yet this is clearly untrue, for we stand in relation to them as the eye of the owl to the sun, as Aristotle says.

To these arguments it is replied according to the aforesaid opinion. The possible intellect, so far as it is self-subsistent, understands separate substances, and is in potentiality to them as a transparent body to the light. Whereas in so far as it is in touch with us, it is in potentiality from the beginning to forms abstracted from the phantasms. Hence we do not from the beginning understand separate substances by it. But this will not hold. For the possible intellect, according to them, is said to be in touch with us, through being perfected by intelligible species abstracted from the phantasms. Consequently the intellect is to be considered as in potentiality to these species before being in touch with us. Wherefore it is not by its being in touch with us that it is in potentiality to these species.

I'urther. According to this, the fact of its being in potentiality to these species would belong to it not in itself but through something else. Now a thing ought not to be defined by those things which do not belong to it in itself. Therefore the definition of the possible intellect should not be taken from its being in potentiality to the aforesaid species, as Aristotle defines it in 3 De Aninia.

Further. It is impossible for the possible intellect to understand several things at the same time, unless it understand one through another: since one power is not perfected at the same time by several acts except according to order. If, therefore, the possible intellect understands separate substances, and species abstracted from phantasms, it must either understand separate substances through these species, or vice versa. Now whichever be granted, it follows that we understand separate substances. For if we understand the natures of sensibles forasmuch as the possible intellect understands them, and the possible intellect understands them through understanding separate substances, we must understand them in the same way. And in like manner if the case be the reverse. But this is clearly false. Therefore the possible intellect does not understand separate substances: and consequently it is not a separate substance.