That the Potential Intellect is not One and the Same in all Men

HENCE it is plainly shown that there is not one and the same potential intellect, belonging to all men who are and who shall be and who have been, as Averroes pretends.*

A.1. It has been shown that the substance of the intellect is united with the human body and is its form (Chap. LVII). But it is impossible for there to be one form otherwise than of one matter. Therefore there is not one intellect for all men.

A.2 and 3.* It is not possible for a dog's soul to enter a wolf's body, or a man's soul any other body than the body of a man. But the same proportion that holds between a man's soul and a man's body, holds between the soul of this man and the body of this man. It is impossible therefore for the soul of this man to enter any other body than the body of this man. But it is by the soul of this man that this man understands. Therefore there is not one and the same intellect of this man and of that.

A.4. A thing has being from that source from whence it has unity: for one and being are inseparable. But everything has being by its own form. Therefore the unity of the thing follows the unity of the form. It is impossible therefore for there to be one form of different individual men. But the form of any individual man is his intellectual soul. It is impossible therefore for there to be one intellect of all men.

But if it is said that the sentient soul of this man is other than the sentient soul of that, and so far forth the two are not one man, though there be one intellect of both, such explanation cannot stand. For the proper activity of every being follows upon and is indicative of its species. But as the proper activity of an animal is to feel, so the proper activity of a man is to understand. As any given individual is an animal in that he has feeling, so is he a man by virtue of the faculty whereby he understands. But the faculty whereby the soul understands, or the man through the soul, is the potential intellect. This individual then is a man by the potential intellect. If then this man has another sentient soul than another man, but not another potential intellect, but one and the same, it follows that they are two animals, but not two men.

B. To these arguments the Commentator replies by saying that the potential intellect is conjoined with us through its own form, namely, through an intelligible impression, one subject of which [is the said potential intellect, and one subject again] is the phantasm existing in us, which differs in different men; and thus the potential intellect is multiplied in different men, not by reason of its substance, but by reason of its form.

The nullity of this reply appears by what has been shown above (Chap. LIX), that it would be impossible for any man to have understanding, if this were the only way in which the potential intellect were conjoined with us. But suppose that the aforesaid conjunction (continuatio) were sufficient to render man intelligent, still the said answer does not solve the arguments already alleged.

B.1. According to the above exposition, nothing belonging to intellect will remain multiplied as men are multiplied except only the phantasm, or impression in phantasy; and this very phantasm will not be multiplied as it is actually understood, because, as so understood, it is in the potential intellect, and has undergone abstraction of material conditions under the operation of the active intellect; whereas the phantasm, as a potential term of intelligence, does not transcend the grade of the sentient soul.

B.2. Still the objection holds, that this man will not be differentiated from that except by the sentient soul; and the awkward consequence follows that this man and that together do not make a plurality of men.

B.3. Nothing attains its species by what it is potentially, but by what it is actually.* But the impression in phantasy, as multiplied in this man and that, has only a potentially intelligible being. Therefore that impression, as so multiplied, does not put any given individual in the species of 'intelligent animal,' which is the definition of 'man.' Thus it remains true that the specific ratio of 'man' is not multiplied in individual men.

B.4. It is the first and not the second perfection* that gives the species to every living thing. But the impression in phantasy is a second perfection; and therefore not from that multiplied impression has man his species.

B.6. That which puts a man in the species of man must be something abiding in the same individual as long as he remains: otherwise the individual would not be always of one and the same species, but now of one species and now of another. But the impressions of phantasy do not remain always the same in the same man; but new impressions come, and previous impressions perish. Therefore the individual man does not attain his species by any such impression: nor is it anything in the phantasy that conjoins him with the formal principle of his species, which is the potential intellect.

C. But if it is said that the individual does not receive his species by the phantasms themselves, but by the faculties in which the phantasms are, namely, the phantasy, the memory, and the vis cogitativa which is proper to man, and which in the De anima, III, v, Aristotle calls the 'passive intellect,'* the same awkward consequences still follow.

C.1. Since the vis cogitativa operates only upon particulars, the impressions of which it puts apart and puts together;* and further, since it has a bodily organ through which it acts,* it does not transcend the rank of the sentient soul. But in virtue of his sentient soul, as such, man is not a man, but an animal. It still therefore remains true that the element, supposed to be multiplied in us, belongs to man only in his animal capacity.

C.2. The cogitative faculty, since it acts through an organ, is not the faculty whereby we understand. But the principle whereby we understand is the principle whereby man is man. Therefore no individual is man by virtue of the cogitative faculty: nor does man by that faculty essentially differ from dumb animals, as the Commentator pretends.

C.3. The cogitative faculty is united to the potential intellect, the principle of human intelligence, only by its action of preparing phantasms for the active intellect to render them actual terms of intelligence and perfections of the potential intellect. But this preliminary activity of the cogitative faculty does not always remain the same in us. Therefore it cannot be the means whereby man is conjoined with the specific principle of the human species, or made a member of that species.

C.4. If the potential intellect of this and that man were numerically one and the same, the act of understanding would be one and the same in both which is an impossibility.

D. But if it is said that the act of understanding is multiplied according to the diversity of impressions in phantasy, that supposition cannot stand.

D.3. For the potential intellect understands a man, not as this individual man, but as man simply, according to the specific essence of the race. But this specific essence remains one, however much impressions in phantasy arc multiplied, whether in the same man or in different men. Therefore no multiplication of phantasms can be the cause of multiplication of the act of understanding in the potential intellect, considering the same species; and thus we shall still have numerically one action in different men.

D.4. The proper subject in which the habit of knowledge resides is the potential intellect. But an accident, so long as it remains specifically one, is multiplied only by coming to reside in different subjects. If then the potential intellect is one in all men, any habit of knowledge specifically the same, say, the habit of grammar, must be numerically the same in all men, which is unthinkable.

E. But to this they say that the subject of the habit of knowledge is not the potential intellect, but the passive intellect and the cogitative faculty (Chap. LX): which it cannot be.

E.1. For, as Aristotle shows in the Ethics (II, i), like acts engender like habits; and like habits reproduce like acts. Now by the acts of the potential intellect there comes to be the habit of knowledge in us; and we are competent for the same acts by possession of the habit of knowledge. Therefore the habit of knowledge is in the potential intellect, not in the passive.

E.2. Scientific knowledge is of demonstrated conclusions; and demonstrated conclusions, like their premises, are universal truths.* Science therefore is in that faculty which takes cognisance of universals. But the passive intellect is not cognisant of universals, but of particular notions.

F. The error of placing the habit of scientific knowledge in the passive intellect seems to have arisen from the observation that men are found more or less apt for the study of science according to the several dispositions of the cogitative faculty and the phantasy.

F.1. But this aptitude depends on those faculties only as remote conditions: so it also depends on the complexion of the body, as Aristotle says that men of delicate touch and soft flesh are clever.* But the proximate principle of the act of speculative understanding is the habit of scientific knowledge: for this habit must perfect the power of understanding to act readily at will, as other habits perfect the powers in which they are.

F.2. The dispositions of the cogitative faculty and the phantasy regard the object: they regard the phantasm, which is prepared by the efficiency of these faculties readily to become a term of actual understanding under the action of the active intellect. But habits do not condition objects: they condition faculties. Thus conditions that take the edge off terrors* are not the habit of fortitude: fortitude is a disposition of the conative part of the soul to meet terrors. Hence it appears that the habit of knowledge is not in the passive but in the potential intellect.

F.3. If the potential intellect of all men is one, we must suppose that the potential intellect has always existed, if men have always existed, as Averroists suppose; and much more the active intellect, because agent is more honourable than patient, as Aristotle says (De anima, III, v).* But if the agent is eternal, and the recipient eternal, the contents received must be eternal also. Therefore the intellectual impressions have been from eternity in the potential intellect: therefore it will be impossible for it to receive afresh any new intellectual impressions. But the only use of sense and phantasy in the process of understanding is that intellectual impressions may be gathered from them. At this rate then neither sense nor phantasy will be needed for understanding; and we come back to the opinion of Plato, that we do not acquire knowledge by the senses, but are merely roused by them to remember what we knew before.*

G. But to this the Commentator replies that intellectual presentations reside in a twofold subject: in one subject, from which they have everlasting being, namely, the potential intellect; in another subject, from which they have a recurring new existence, namely, the phantasm, or impression in phantasy. He illustrates this by the comparison of a sight-presentation, which has also a twofold subject, the one subject being the thing outside the soul, the other the visual faculty. But this answer cannot stand.

G.1. For it is impossible that the action and perfection of the eternal should depend on anything temporal. But phantasms are temporal things, continually springing up afresh in us from the experience of the senses. Therefore the intellectual impressions, whereby the potential intellect is actuated and brought to activity, cannot possibly depend on phantasms in the way that visual impressions depend on things outside the soul.*

G.2. Nothing receives what it has already got. But before any sensory experience of mine or yours there were intellectual impressions in the potential intellect: for the generations before us could not have understood had not the potential intellect been reduced to act by intellectual impressions. Nor can it be said that those impressions, formerly received in the potential intellect, have ceased to be: because the potential intellect not only receives, but keeps what it receives: hence it is called the "place of ideas."* Therefore, on this showing, no impressions from our phantasms are received in the potential intellect.

G.6 and 7. If the potential intellect receives no intellectual impressions from the phantasms that are in us, because it has already received them from the phantasms of those who were before us, then for the like reason we must say that it receives impressions from the phantasms of no generation of men, whom another generation has preceded. But every generation has been preceded by some previous generation, if the world and human society is eternal, as Averroists suppose. Therefore the potential intellect never receives any impressions from phantasms; and from this it seems to follow that the potential intellect has no need of phantasms to understand. But we (nos) understand by the potential intellect. Therefore neither shall we need sense and phantasm for our understanding: which is manifestly false and contrary to the opinion of Aristotle.*

For the potential intellect, like every other substance, operates according to the mode of its nature. Now according to its nature it is the form of the body. Hence it understands immaterial things, but views them in some material medium; as is shown by the fact that in teaching universal truths particular examples are alleged, in which what is said may be seen. Therefore the need which the potential intellect has of the phantasm before receiving the intellectual impression is different from that which it has after the impression has been received. Before reception, it needs the phantasm to gather from it the intellectual impression, so that the phantasm then stands to the potential intellect as an object which moves it. But after receiving the impression, of which the phantasm is the vehicle, it needs the phantasm as an instrument or basis of the impression received. Thus by command of the intellect there is formed in the phantasy a phantasm answering to such and such an intellectual impression; and in this phantasm the intellectual impression shines forth as an exemplar in the thing exemplified, or as in an image.*

G.8. If the potential intellect is one for all men and eternal, by this time there must have been received in it the intellectual impressions of all things that have been known by any men whatsoever. Then, as every one of us understands by the potential intellect, -- nay, as the act of understanding in each is the act of that potential intellect understanding, -- every one of us must understand all that has been understood by any other men whatsoever.

H. To this the Commentator replies that we do not understand by the potential intellect except in so far as it is conjoined with us through the impressions in our phantasy, and that these phantasms are not the same nor similar amongst all men. And this answer seems to be in accordance with the doctrine that has gone before: for, apart from any affirmation of the unity of the potential intellect, it is true that we do not understand those things, the impressions whereof are in the potential intellect, unless the appropriate phantasms are at hand. But that this answer does not altogether escape the difficulty, may be thus shown.

When the potential intellect has been actualised by the reception of an intellectual impression, it is competent to act of itself: hence we see that, once we have got the knowledge of a thing, it is in our power to consider it again when we wish: nor are we at a loss for lack of phantasms, because it is in our power to form phantasms suitable to the consideration which we wish, unless there happens to be some impediment on the part of the organ, as in persons out of their mind or in a comatose state. But if in the potential intellect there are intellectual impressions of all branches of knowledge, -- as we must say, if that intellect is one and eternal, -- then the necessity of phantasms for the potential intellect will be the same as in his case who already has knowledge, and wishes to study and consider some point of that knowledge, for that also he could not do without phantasms.* Since then every man understands by the potential intellect so far as it is reduced to act by intellectual impressions, so every man should be able on this theory to regard, whenever he would, all the known points of all sciences: which is manifestly false, for at that rate no one would need a teacher. Therefore the potential intellect is not one and eternal.