Commentaria in Primam Partem Summae Theologiae

Title. Knowledge: by the name of knowledge we understand cognition grasped by the intellect, certain and evident.

In the body, one conclusion, answering the question affirmatively: In God there is knowledge most perfectly. – It is proved. Immateriality is the reason why something is cognitive; and according to the mode of immateriality is the mode of cognition. But God is at the summit of immateriality. Therefore God is at the summit of cognition: which is to have knowledge most perfectly.

The major premise has two parts, and it is proved with respect to each. With respect to the first part, in two ways. First, by reason, thus. A knowing being has its esse from having its own form and that of another: therefore from the amplitude of its nature: therefore from immateriality. The antecedent is proved: because in this the knowing being differs from the non-knowing. Now the first consequence is evident of itself: because what is itself and other things is more ample than what is itself only. And it is confirmed by the authority of Book III On the Soul: the soul is in a way all things. But the second consequence is proved from what was said in question VII, that the restriction of form comes from matter, and the infinity of forms through recession from matter. – Second, the major premise is proved by the authority of Aristotle, Book II On the Soul, that plants do not know, on account of their materiality.

As to the second part, the major is proved from the degrees of knowing in sense and intellect. The latter is cognitive because it receives species without matter; the former more so, because it is separate and unmixed, as is said in Book III On the Soul. But the minor is evident from what was said above.

II. Concerning the difference assigned between cognizing and non-cognizing things, a doubt is raised. Either, when it is said that the cognizing being is naturally apt to be also other things, you mean that the word to be is understood by identity; and thus it is false, since the intellective soul is not naturally apt to be the same as a stone, an ox, etc. Or by information: and then, either by intentional information, and thus the difference is false, because air is non-cognizing and yet receives colors intentionally; or by natural information, and then it is most false, both because the stone is not in the soul, and because non-cognizing things are in this way other.

Similarly, ly other either stands for all: and thus it is false, because a sense is not naturally apt to be all things, but only certain ones. Or it stands for certain ones: and thus there is no difference; for it is common to all things that are among us to be not only themselves, but also certain other things in some way, namely by information; for all things are not only substances in themselves, but have at least their own accidents conforming to their proper natures; for fire is not only fire, but light, rare, luminous, hot. And just as these things have their own accidents, so the knower has its own proper accidents, the intentional species. Hence in this respect no difference appears between knowers and non-knowers.

III. To make evident this difficult and arduous foundation of a great part of metaphysics and natural philosophy, two things must be done: first, a formal reply must be given to the objections; second, the root of all of them must be brought to light ¹. To the objections it is easily said that the term being abstracts from the modes of being by identity or by information; and likewise the term other abstracts from all or some, just as the term cognitive abstracts from this or that kind of cognitive power. For some knowing being is one that is all things by identity, as God; some is some things by identity and some things by information, as the angels; some is all things by information, as our soul; and some is some things by information, as the purely sensitive soul. And therefore difference taken in common abstracts from all these modes, so that none is excluded but all are contained confusedly.

IV. But this root becomes clear if we consider the essential difference between the mode in which the knower is the known, and that in which matter has form. And likewise, how differently a unity comes about from knower and known, than from matter and form: for the same judgment applies to being (esse) and to one, since they signify the same nature, as is said in Book IV Metaphysics ². It must be known, therefore, that the essential difference lies in this: that the knower is itself the known actually or potentially, whereas matter is never the form itself. From this difference with respect to being (esse) there follows a difference with respect to unity: namely, that knower and known are more one than matter and form, as Averroes said most excellently in Book III of On the Soul, commentary V ³. And he gave the reason stated above, because from intellect and what is understood no third thing results, as it does from matter and form: for by assigning as the reason for the greater unity the exclusion of a third thing, he clearly taught that unity consists in this, that one is the other. Hence Aristotle, in Book III of On the Soul ⁴, taught this same point beforehand, saying that the soul is all sensible and intelligible things. That this is the true essential difference is shown by the fact that all common conceptions of the mind and conclusions accord with it: namely, that there occurs between the cognitive power and the known a diversity between them, and likewise their composition; and likewise, that the known has intentional being (esse) in the knower; and that in no nature can matter and form, subject and accident, be raised so high that one may be the same as the other while their proper natures remain intact, as we find to be the case with knower and known.

V. The necessity of this position arises from two theses. The first is: each thing acts insofar as it is in act, from III Physics⁵ The second is: the known is the specifying principle of cognition, from XII Metaphysics⁶ From these it follows that, since the knower must be a sufficient principle of its own operation, which is to know—because this is common to all perfect natures—it must be the specifying principle of that operation: which is to be the thing known. And if you add to these, from II On the Heavens, text. comm. XVII⁷, that each thing exists for the sake of its own operation, it follows that the cognitive nature is of such a kind in itself as to be, in act or in potency, the very thing known: which is to be not only itself, but another, as the text says. VI. And if you compare this to the other beings, you will see the difference between cognizing and non-cognizing things made manifest from this. For the other beings either receive forms on account of the operations of those forms themselves; or on account of the operation of a third thing, the composite of receiver and received. An example of the first is hot water, and universally in subject and accidental form: for heating is not the proper operation of water, but of heat. And the same judgment holds, in this respect, for cold water: for although coldness is a natural potency of water, yet making cold is the proper operation of coldness, not of water. An example of the second is clear in substantial forms: for matter does not receive form on account of the operation of matter itself, but of the composite of itself and form. But the knower, receiving the known, does not receive it on account of the operation of some composite resulting from them, nor on account of the operation of the known itself; but on account of the specification of its own proper operation as knower. For sight receives the visible on account of the species of vision, which is admittedly sight's proper operation. Nor does it stand in the way that the visible, as received in sight, is an accident, and sight the subject: since this is per accidens, that is, from the necessity of matter, and is not what is intended first per se. For the form, intention, or species of the visible specifies not insofar as it is an accident, but insofar as it is visible⁸ passing into vision; but because such sensible nature cannot undergo this except through the esse of an intention, therefore, on account of matter, an accident concurs. Yet it does not destroy what is intended per se, but establishes it at a less perfect degree. For as must be discussed elsewhere⁹, and as is held by Averroes in XII Metaphysics¹⁰ and III On the Soul¹¹, knower and known are not one with the same intention in all cases, but more or less diminishedly; so much so that in God alone are they entirely identical. VII. And thus the assigned differences are clear¹², and how subtly this saintly Thomas handed down the nature of cognizing things. That it consists in this is shown not only from Aristotle and Averroes, as appears from what has been said, but also from Albert in his treatise on Intellect and the Intelligible¹³. And this must be held most diligently as a foundation, whenever there is talk of intellect: since upon it depend the conclusions of many questions, for instance concerning the concurrence of object and intellect in intellection, and likewise concerning the concurrence of the intelligible species, etc. And hence it appears how crude were those who, treating of sense and the sensible, intellect and the intelligible, and of understanding and sensing, judge of them as if they were other kinds of things. And you will learn to raise up your mind and enter into another order of things.