Commentaria in Summam contra Gentiles, Liber II

After St. Thomas had attacked the Commentator's opinion concerning the unity of the possible intellect, he now wishes to respond to its arguments ¹.

I. Its first ² argument, however, was that, if the possible intellect were multiplied according to number, it would be a material form, and consequently it would neither receive anything nor operate without a bodily organ. Which is contrary to the nature of the possible intellect. — The consequence is proved. Because every form that is one according to species and multiplied according to number is individuated through matter. But every form individuated through the matter of which it is the act is a material form: since the being of any thing must depend on that on which its individuation depends, because the individuating principles belong to the essence of this individual.

2. It is answered, and it is said first, that the intellect is one in species and many according to number: — so that no force is made of this, that the parts of man are not placed in a genus or in a species in themselves, but only as they are principles of the whole.

It is said second, that the consequence is false, if material form is taken for a form dependent on matter with respect to its esse.

It is said third, in proof of the consequence, that human souls, and consequently the possible intellect, which is a power of the soul, are individuated according to bodies—not as though individuation were caused by the bodies, but from this, that they have a relation to one body and to another.

II. Concerning this response, doubt is raised in several ways. For it does not seem to satisfy the argument. First, because it seems false that the individuation of souls is not caused by bodies. Then also because, as was touched upon in the argument, the individuating principles are of the essence of this individual, just as the common principles are of the essence of the species. But each thing depends on and is caused by its essential principles. Therefore the individuation of souls depends on and is caused by the body through which it is individuated.

Then, because the relation of the soul to the body is the relation of form to matter, and matter is the cause of form according to the genus of material cause, it follows that, if the soul is individuated by its relation to the body, the body would be the cause of the soul and of its individuation.

2. Second, ³, because it seems false that souls are individuated by their relation to bodies: for a substance is not individuated except by substance, as is said in the First Part, q. 29, a. 1. But this relation of the soul to the body is not a substance. Therefore the soul is not individuated by that relation.

III. For the solution of these points, one must recall what was touched upon above, in chapter lxviii ⁴, where it was shown how the intellectual soul is not a form comprehended by matter nor dependent on matter. For it was said there that, although the intellectual soul has its esse in matter, it nevertheless does not depend on matter, because its esse is not bound to matter, as though it needed to be sustained by matter and could not exist without it; rather, separated from matter it can have its esse. And therefore it was said there that matter is not the cause of the intellectual soul in the genus of material cause, and that it is not educed from the potency of matter.

From these things it follows that matter is not the cause of the individuation of the soul, although it has its individuation in matter. For just as its esse can be without matter, and on this account it does not depend upon nor is it caused by individual matter with respect to its esse, so also, when separated from matter, it retains its individuation, and it does not need to be sustained by individual matter with respect to its individuation. And therefore its individuation is not caused by matter, although it receives individuation in individual matter. On this account Saint Thomas says well, and in conformity with his doctrine, that souls are indeed individuated according to bodies, but their individuation is not caused by the bodies.

IV. Hence, in reply to the first objection against this view, it is said that if by individual is understood a composite of matter and form, then since two things concur to individuation, as was shown in the first book ⁵—namely, matter and quantity—each is not said of the essence of the individual in the same way: rather, matter is said of the essence as constituting its essence; but quantity, because it is posited in its definition as a determinant of the essence. However these things may be of the essence of the individual, they are nevertheless not the cause of the individuation of the supposit and human individual with respect to esse, although matter is its cause with respect to the very essence, in the way that a part is the cause of the whole: for they do not cause the esse of that supposit, since it is wholly from an extrinsic source, just like the intellectual soul. — But if by the name "individual" there be taken the very individuated soul, which is this one and singular, then neither matter nor quantity is of the essence of the soul as though the body itself constituted the soul's essence, but only because it is posited in its definition (for everything posited in the definition of something can be said, broadly speaking, of its essence): for, just as the soul according to its own essence has a relation to the body, inasmuch as it is essential to it that it be the form of a body, as is said in On Spiritual Creatures, art. 9, ad 4, so too this soul, inasmuch as it is this soul, has a relation to this body, and this body is posited in its definition. But although this body is thus of the essence of this soul, it need not therefore be the cause of its individuation, just as it is not the cause of its esse: just as, although a similar thing bears a relation to another similar thing, yet the other similar thing is not its cause in any genus of cause. And so souls must be distinguished materially according to the distinction of bodies, inasmuch as the soul has a natural relation to the body, and it must be proportioned and fitted to it, as will be said below, chapter lxxxi; yet the body is not the cause of the individuation of the soul, nor is the multitude of bodies the cause of the multitude of souls.

From these things it is evident that the minor proposition assumed has truth concerning what is of the essence of something as constituting its essence, insofar indeed as regards the essence which it constitutes, but not universally as regards its esse: because, as was shown, the matter of an individual human is indeed a cause of his essence inasmuch as it is a part, yet it is not a cause of esse, since his esse is not educed from the potency of matter. — Nor, however, is the proposition universally true when said of what is said of the essence of a thing because it enters into its definition in some way: in which way we said body to be of the essence of the soul.

2. To the second objection against the said proposition, it is said that indeed the relation of the soul to the body is the relation of form to matter; but the minor proposition is false if it is understood universally of every form. For matter is the cause only of that form which is educed from its potency; but of a form which is not educed from its potency, although matter is receptive, it is nevertheless not the cause. Hence, when it is said that form is individuated by individual matter, the word by does not signify causality, but only the relation of matter in which the form receives individuation, if we are speaking of the intellectual soul. But if we are speaking of other forms, it signifies the relation of cause: because the other forms which are in matter are educed from the potency of matter, and thus matter is for them simply the cause of their esse.

But if one presses the objection thus: The causality of matter is nothing other than to receive form. Therefore matter is the cause of every form received in it — the reply is that the causality of matter is not to receive absolutely, but to receive a form educed from its potency, and to receive in the manner of a sustainer, which is to receive form in such a way that it cannot be without matter. Hence Saint Thomas, speaking of the causality of form and matter in V Metaphysics, in the chapter on Cause ⁶, says that form is the cause of matter, inasmuch as it gives to it esse in act; but matter is the cause of form, inasmuch as it sustains it.

3. But attention must be given to what is said in the same place, namely that matter is sometimes the cause of the form's being (essendi), insofar as it is the form of this thing, having esse in this thing; that is, it is the cause of being (essendi) in a qualified sense, and sustains it in a qualified sense: just as the human body is related to the rational soul. For from these considerations it is gathered that matter is not absolutely and simply the cause of the intellectual soul, as simply sustaining it, so that it could not exist at all except in matter, since when separated from matter it has esse; but it is indeed the cause of the soul's being (essendi) in a qualified sense, inasmuch as it is the cause that it is the form of this thing, having esse in this individual. For in this respect matter sustains the soul: because it cannot be the form in act of this individual, say Socrates, having esse in him as a part of him, unless it be in matter; for when separated from matter, although it has esse, it does not nevertheless have esse in Socrates. — And thus it is clear how what Saint Thomas says is to be understood, that the intellectual soul does not depend on matter with respect to its esse: for it is understood that it does not depend on matter simply. But it can indeed depend on it in a qualified sense.

And because the individuation of the soul accompanies its esse, we may say that this is the mind of St. Thomas: that designated matter is not indeed the cause of the individuation of the intellective soul simply; but it is well the cause of individuation in a certain respect, inasmuch as it is the cause of it as it is the form of this body, existing in that very body.

And thus it can also be understood when it is said that matter under quantity is the principle of individuation. For although in other things it is the cause of individuation simply, yet in the intellectual soul it is a principle in a certain respect, and a principle without which the soul is not individuated.

V. To the second ⁷ it is said first that the individual of a substance can be considered in two ways: in one way, insofar as it is incommunicable; in another way, insofar as it is this determinate thing, distinct from all other individuals of the same species. Therefore what Saint Thomas says, namely that substance is individuated through itself, must be understood with respect to the first condition of the individual: for it is incommunicable through matter, which is the ultimate subject; and matter is substance. But with respect to the second condition, it is individuated through quantity, which is an accident. — There are also other interpretations of this proposition put forward by others, which I do not reject. See them there.

It is said second, that St. Thomas does not say this soul differs from that one on this account alone, namely because it has a relation to another body, as if the relation to the body were simply and absolutely the cause of individuation; but rather because it is a condition without which the soul is not individuated. For this soul would not be what it is unless it were essentially fitted to this body. And thus we may also say that individual matter is the cause without which the intellective soul is not individuated; but it is not the cause simply causing individuation itself in the soul.

VI. The second ⁸ argument was Averroes's. The intellect is multiplied according to number. Therefore the intelligible species are also multiplied according to number. Therefore they are individual forms. Therefore they are not actually intelligible. This is false. Therefore, and so on. — The first consequence is proved: because the proper subject of the intelligible species is the intellect. — The second is also proved: because forms that are the same in species and diverse in number are individual forms. — The third is also proved: because intelligibles are universals, not particulars.

2. The answer is given, and it is said first that the argument proceeds from a false foundation, namely, that the intelligible species is that which is understood, and not merely that by which it is understood: whereas it is that by which it is understood (just as the species of color in the eye is that by which we see), but not that which is understood. For that which is understood is the very ratio of things existing outside the soul, that is, the very nature presented to the intellect, which exists in singulars. Otherwise all the sciences and arts, since they are concerned with things understood, would be concerned with the species that are in the intellect, and not only natural philosophy ⁹ and metaphysics.

It is said second, that there need not be one species in number, intelligible, of this intellect and of that one. For it would follow that the act of understanding would be one in number of this intellect and of that one, since operation follows the form which is the principle of the operation. And therefore the falsity of the first consequent, understood in the reason, is denied.

It is said thirdly that it does not follow that, if the intelligible species are many in number and the same in species, they are not intelligible in act but only in potency, like other individuals. For being an individual is not repugnant to being intelligible in act: for the possible and the agent intellect, if they are posited as separate, will be individuals, and yet they are intelligible. But materiality is what is repugnant to intelligibility. Now the intelligible species are immaterial: for they are not individuated by matter, but by the possible intellect, which is immaterial. Hence the final consequence is denied.

It is said in the fourth place that it makes no difference, for the species received in the intellect to be actually intelligible, whether the possible intellect be one in all or many. For they are individuated by the intellect in the same way whether it be one or there be many, although they are not multiplied within the same species in the same way: just as among sensible things the individuals that are unique within one species, such as this sun and this moon, are not actually intelligible, as those that are many within one species, such as horses or men. And thus it is clear that this argument concludes as much against one who posits only a single intellect as against one who posits many intellects.

It is said fifth, that neither is the multiplication of the possible intellect the cause of the multiplicity of species, as the first consequence seems to suppose. For even in the Commentator, who posits several intelligible substances, in whose order the intellect is the last, some of the higher substances know the same things that the possible intellect knows, since in the movers of the spheres, according to him, there are the forms of those things that are caused by the motion of the spheres. And thus intelligible forms are multiplied according to the multiplication of intellects, but not according to the multiplication of the possible intellect.

VII. But against this reply one could object in many ways. First, against the first statement, by proving that the species is that which is understood, and not the thing outside the intellect, as was said there. For the sciences are concerned with universals. If, therefore, the thing that is understood is a thing outside the soul, it follows that universals exist outside the soul. And thus Plato's opinion will be true.

It is answered that universals are indeed outside the soul: not, however, subsisting in themselves, as Plato held, but existing in singulars. And the intellect understands them insofar as it understands the nature of genus and species, without understanding the principles of individuation. This happens because the intelligible species has been made immaterial by the agent intellect, being abstracted from matter and the conditions of matter, by which something is individuated ¹⁰.

But if it be urged against this, that for true cognition it is required that the cognition of a thing correspond to the thing: therefore, if the nature outside the intellect is singular, it must be cognized outside the intellect as singular — it is said that indeed the cognition of a thing must correspond to the thing; yet it is not required that the mode of cognition and the mode of the thing be the same ¹¹ For things that are conjoined in reality are sometimes cognized separately, as is clear in the case of whiteness and sweetness, when one thing is at once white and sweet, and in the case of a line and sensible matter, either of which can be cognized without the other. And so, although the nature of genus and species is never found except in individuals, the intellect nevertheless understands them without understanding the principles of individuation. Hence that consequence is denied.

2. Second, an objection could be raised against the second statement, proving that there must be one species in number for this and that intelligent being with respect to the same intelligible object. For then there would not be one thing understood, since the species is the very act of understanding.

It is answered by denying the consequence. For in order that there be one thing understood by many on the side of the thing that terminates cognition, it is not necessary that there be one species, since the species itself is not the very thing understood, but its likeness. Rather, what is required is that there be a likeness of one and the same thing in them. This, however, is possible even if the intelligible species are diverse in number: for nothing prevents several likenesses differing from one another from being formed of one and the same thing.

3. Finally, someone might ask whether the intelligible species are such that they are precisely that by which something is understood, while they themselves are in no way understood.

Saint Thomas responds that they are indeed understood, but by reflection, just as the act of understanding itself is: both as regards knowledge of it in the singular and as regards knowledge of it in the universal; that is, as regards knowledge whether it exists, when one knows oneself to have a species; and as regards knowledge what it is, by knowing its nature.

4. Concerning that statement at the beginning of the response ¹², namely that only the natural philosopher and the metaphysician consider the intelligible species, it must be considered that, although each of them considers those species, this is nevertheless not in the same way. For the natural philosopher considers them insofar as they are grounded in phantasms and are caused by natural things, and in the same manner in which he considers the intellect: namely, insofar as they are something of the intellective soul, which is a natural form, inasmuch as they exist as the proper form of the possible intellect. The metaphysician, however, considers them both insofar as they are certain beings and insofar as they are immaterial: just as he also considers the possible intellect insofar as it is immaterial.

VIII. Concerning the reply to the first objection ¹³, where it is said that the reason why the intellect knows the nature of genus and species stripped of the individuating principles is the condition of the intelligible species received in it, which has been made immaterial by the agent intellect, it must be noted that the abstraction of the species from matter and the conditions of matter with respect to its esse gives to the species, as the nature of which it is the likeness, an immaterial representation, that is, one without material conditions. And because the intellect is borne toward the object as it is represented to it by its likeness existing in itself, as is the case with every other cognitive power, therefore by that very species it apprehends the nature without material conditions. But the words of St. Thomas must be attended to. For he does not say that the intellect understands the nature without material conditions because the species is immaterial, as though the immateriality of the species were the reason why it represents the nature without material conditions; for this is not true in his doctrine, since he holds that the species which are in the angelic mind represent not only the nature of the species but also the individual conditions ¹⁴, and yet it is evident that they are immaterial. But he says that this happens because it has been made immaterial by the agent intellect, inasmuch as it is abstracted etc. For not because it is immaterial absolutely, but because by the agent intellect it is abstracted from the phantasms, and by that same intellect, in thus abstracting it, it is made immaterial, therefore it so represents; for as it is abstracted by the agent intellect, so does it represent. But this does not belong to the species which are in the angelic mind, but only to the species of our intellect.

2. In the same response, where it is said that although for the truth of cognition it is necessary that the cognition of a thing correspond to the thing, nevertheless the mode of cognition and of the thing need not be the same ¹⁵, we must consider that Saint Thomas gives us to understand the distinction he makes in Prima, q. 85, a. 1, ad 1, and elsewhere: namely, that the mode of knowing can be taken in two ways, namely on the part of the thing known, and on the part of the knower. The mode of cognition on the part of the thing known must be proportioned to the mode of the thing itself known, so that the thing is known to be as it is; and if it is known otherwise than it is, there is no true cognition of the thing. But the mode belonging to the part of the knower need not be proportioned to the mode of the thing known: because the intellect knows immaterially things that have material esse, and it understands in a divided and separate way things that are conjoined in their esse. He signified the first when he said it is necessary for the truth of cognition that the cognition of a thing correspond to the thing; but the second when he said, nevertheless the mode of cognition and of the thing need not be the same.

3. But a doubt arises. For, if the mode of cognition, considered on the side of the thing, must be proportioned to the mode of the thing understood, then if the thing understood exists in itself joined to individual conditions, it will be necessary that it be known as joined to those conditions, and not apart from individual conditions. And if it is understood apart from those conditions, it follows that in reality it exists without them. And thus Saint Thomas does not seem to answer the objection raised. For there still remains either that the thing understood is not a thing outside the soul, since what is understood is universal, or that universals exist outside singulars.

It is answered that the mode of cognition considered on the side of the knower, as it is taken here, is the mode of knowing insofar as something is represented to the knower by a species. And this is to know by simple apprehension. And because what is joined to another in itself can be represented without that to which it is joined—just as the species of color existing in the eye represents the color of the apple but not its sweetness, and the species of the intellect represents the nature without representing the individuating principles to which it is joined—therefore it happens that the knower apprehends one thing without another. And thus the mode of cognition is one thing, and the mode of the thing known, taken absolutely as it is outside the soul, is another. — By the mode of cognition on the side of the thing known, however, is understood the mode of knowing insofar as something is apprehended as being in the thing. And this is to know by the second operation of the intellect, which terminates in the esse of the thing, when the intellect says that something is or is not. And then the mode of cognition must be proportioned to the mode of the thing known: so that it says that what is, is, and that what is not, is not. And thus it must say that the species is in the individuals, if it is to be true: for if it were to say that it is not in the individuals, it would speak falsely and would know falsely.

Hence, to the argument: the consequence is denied, if the cognition in question is understood as simple apprehension; for one passes from a way of holding that depends on the side of the thing known to a way of holding that depends on the side of the knower. — But if it is understood of cognition that is composition and division, the first consequence is granted; for the intellect must understand the nature as joined to individual conditions, just as it is in the thing; and if it judged otherwise, it would be false. — But the final consequence is denied. For we do not say that universals are understood as abstracted from singulars by the second operation of the intellect, which is to understand that they are not in singulars; but only by the first operation of the intellect, which is to apprehend the nature without considering the individual conditions. And thus the universals themselves are what are understood, not the species that are in the intellect.

IX. Averroes's third argument was this. The teacher transfers the knowledge he possesses, numerically one and the same, into the disciple. Therefore there is one intellect for both. Therefore etc. — The antecedent is proved: because if he were to transfer knowledge only specifically the same, then he would cause knowledge in the disciple just as he causes his own form in something by generating a being like himself; and that belongs to material agents.

X. To this argument Saint Thomas gives a beautiful and lengthy reply. But, in summary, as far as the argument is concerned, it is said first that the antecedent is true of knowledge with respect to what is known, for thus it is one in number in the teacher and in the disciple ¹⁶: but not with respect to the intelligible species by which it is known, nor with respect to the very habit of knowledge; and in this sense it must be understood here. — To its proof, the consequence is denied. For the teacher causes knowledge in the disciple not in the manner of a natural agent reducing matter from potency into act of its form, but in the manner of an art. Hence demonstrative art is given by Aristotle for this purpose: for demonstration is a syllogism that makes one know.

It is said secondly, for a fuller explanation of the answer, that since art is twofold—one in whose material there is no active principle for producing the effect of the art, as the building art; another in whose material there is a productive principle of the effect of the art, as the medical art—when it was said that the teacher causes knowledge by way of art, art is taken in the second way, not the first. Because in the one being taught there is an active principle toward knowledge, namely the intellect and the first principles which are understood naturally ¹⁷; and therefore, just as the physician in healing is the minister of nature, so the teacher teaches by rendering ministry; but God works inwardly, since God is evidently the natural cause of the light of the intellect, by which man causes knowledge in himself.

It is said third, that this argument is not to the point according to the position of the Commentator himself. For, since he posits the habit of the sciences in the passive intellect, the unity of the possible intellect contributes nothing to the numerical unity of the science of master and disciple: since it is agreed that the passive intellect is not one and the same in different persons. But it would be necessary to conclude that there is one passive intellect in all. Which has nothing to do with the point at issue.

XI. Concerning the difference between a natural agent and an agent by art posited by Saint Thomas, it must be understood that this difference can be taken in two ways. In one way, with respect to the mode of acting: namely, that the natural agent acts naturally, that is, from the inclination of its own natural form; whereas the agent through art acts from a purpose. And this is properly the meaning intended by Saint Thomas. For from this it is most clearly evident that the teacher does not act in the manner of material things, which act naturally, as the argument was leading. — In another way, it can be taken with respect to the form produced: as if the natural agent were to act by producing a form similar to the form of the agent, reducing matter from potency into act of its form; but not so the artificial agent. And in this way Saint Thomas does not take the difference posited in this place.

2. Yet nevertheless, although, if his words and intention are carefully considered, only the first sense of this distinction is intended by him; still, because someone might judge that the second sense is also intended by him, on account of some truth in it, to make the matter clear it must be considered that this distinction, taken in that second sense, does indeed have truth, when speaking of a form with respect to the same mode of being — for a natural agent produces a form similar to its own form both with respect to the very character of the form and with respect to the same mode of being, especially an univocal agent; but an artificial agent, although it produces a form similar to its own form with respect to the character of the form, yet not with respect to the same mode of being, as is said in Prima, q. xv, 1, and Potentia, q. vii, 1, ad 8; since the form produced has material esse outside the intellect, whereas in the intellect it has immaterial and intelligible esse — yet it does not have truth universally of a form with respect to the very character of the form. For it is not true of an artificial agent whose matter contains no active principle, that it does not draw matter into act of its form by which it acts: since we see a house-builder introduce into matter the form of a house existing in his intellect, of the same character as the house, though not of the same mode of being. But it is true of the craftsman in whose matter there is an active principle tending to produce the effect of the art. For this is common to every action, that the effect be assimilated to its principal cause with respect to form, but it need not be assimilated to the instrument or minister: because the principal agent acts through the power of its form, but not the instrumental agent, as is said in Tertia, q. lxii, 1, and Malo, q. iv, 1, ad 15 and 16. And therefore the principal agent, in acting, draws matter from potency to act of its form: but the instrumental agent, as such, does not draw matter to act of its own form, but cooperates with the principal agent toward inducing that form into the matter. Since, then, art in whose matter there is no active principle for producing the effect of the art holds the character of a principal agent, just as a natural agent does; therefore, just as a natural agent acts so as to produce a likeness of its form in matter, so also does such a craftsman. And therefore Saint Thomas, in Qq. de Veritate, q. xi, a. 1, says universally and without distinction that when something preexists in passive potency alone, then it is the extrinsic agent which principally draws it from potency into act. But art in whose matter there is an active principle for producing the effect of the art, when compared to that principle which is in the matter, is as an instrument and as a minister to the principal agent, and does not draw matter from potency into act of the art itself, but works ministerially so that what is contained virtually in the principal agent may be unfolded into act: just as the healing art ministers so that health may be introduced into the body, which is contained virtually in the healing power present in the animal. And similarly the teacher, by his knowledge, does not act to introduce his knowledge into the disciple: rather he is a minister so that the knowledge which is contained virtually in the disciple's intellect and in principles naturally known to him, he himself may cause in himself. And therefore he sets before himself propositions and the order of propositions as instruments by which he can cause in himself the habit of science; he also sets forth examples, by which he can form the phantasms necessary for understanding.

3. But a doubt arises. For the student's knowledge of one knowable thing is of the same species as the teacher's knowledge of that same knowable thing. Hence in On Truth, where it was cited above, q. 11, a. 1, ad 6, it is said that through teaching there comes to be in the student a knowledge similar to that which is in the teacher, drawn forth from potency into act. Therefore the teacher, by teaching that knowledge, draws the student from potency into act with respect to his form. For fire is said to draw matter from potency into act with respect to its form for no other reason than because it produces in the matter a form of the same species as the form which it itself has.

It is answered that an agent draws matter from potency into act of its own form in two ways. In one way, because its form is itself the active formal principle by which it produces a form in matter similar to its own form, attaining that form itself by its action. In another way, because it supplies instruments to someone by which the latter may produce a form similar to the form of the one supplying them; or in whatever way it aids another toward the production of that form, while nevertheless not attaining the form itself by its own action. The teacher, therefore, does not draw matter—that is, the intellect of the student—into act of his own form and his own science in the first way, since science, as such, does not have the character of a cause, as is said at I Sent., d. xxxviii, a. 1, and Prima, q. cxvii, 1, ad 2; but only in the second way, inasmuch as through his science the teacher knows which propositions, which demonstrations, or what examples he ought to propose to the student, by which the latter may be aided toward causing science in himself. And therefore the one teaching is not said to draw the student from potency into act of his form except in the second way: just as, if a hot man were to aid in introducing heat into wood by bringing fire near it, he would be said to cause ministerially heat of the same species as the heat he himself has; yet his own heat would not be the formal principle by which he heats the wood. — But the proposition of St. Thomas ¹⁸ is to be understood in the first way, not in the second way. Therefore the argument does not follow.

4. That difference, therefore, posited between the natural agent and the artificial agent according to the second interpretation ¹⁹, namely, that the natural agent draws matter from potency into act of its form, but not the artificial agent, is universally true with respect to form as regards the same mode of being. With respect, however, to the very account of form itself, it is true when comparing a natural agent to that artificial agent alone in whose matter there is an active principle for the production of the form—of which kind is the master, of whom we are here speaking—but not universally when compared to any artificial agent. — Nevertheless, as we said, the first interpretation is more to the point of St. Thomas.

XII. Concerning that proposition, In the one being taught there is an active principle toward knowledge, namely the intellect and those things which are naturally understood, namely the first principles ²⁰, it must be noted that from this manner of speaking, in which the principle existing in the one being taught is distinguished into the intellect and the first principles naturally known, Saint Thomas gives us to understand that the intellect is distinct from the habit of the first principles, and is not the same as the light of the agent intellect, as some maintain. This he states more clearly in I IIae, q. 53, a. 1, where he says that if some habit were caused in the possible intellect immediately by the agent intellect, such a habit would be incorruptible both per se and per accidens. Such are the habits of the first principles, both speculative and practical. And therefore, when Saint Thomas sometimes says that the first principles are known by the natural light of the agent intellect, this is not to be understood as though the very power of the agent intellect were the habit of the first principles; but rather because that habit is not produced in us by discourse and argumentation, as are the habits of the sciences, but is caused immediately by the agent intellect itself in the possible intellect.

2. But a doubt arises concerning the first statement in the response, where it is said that the same science, one in number, is in the disciple and in the master with respect to what is known²¹. For this does not seem to be true. Because what is known is not one in number, but one in species or genus or analogy.

It is answered that what is one in number can be taken in two ways: namely positively, because it is something singular and individual in itself; and negatively, because it is not divided into many according to number. In the first way, the thing known is not said to be one in number, but in the second way it is. For the universal nature abstracted from individual conditions, insofar as it has the character of the thing known, is not divided into several things according to number, since it abstracts from all the principles that divide it as such: but it is one. And thus the knowledge of master and disciple is said to be one in number on the side of the thing known: namely because what both knowledges know is not, as such, divided and multiplied numerically.

Many things could have been brought forward for the explanation of this chapter. But since they have been most fully expounded by Saint Thomas in other places, I deliberately passed them over, aiming at brevity.