Commentaria in Summam contra Gentiles, Liber I

Having shown what the mode is on the side of the thing known by which God knows things other than himself, it remains to investigate what the mode is on the side of the knower ¹. On this point Saint Thomas does two things: first, he treats of the mode on the side of the medium of knowing; second, on the side of the act of knowing itself, in chapter LV. — As to the first, he does two things: first, he rules out certain false modes; second, he shows which is the true mode, in chapter LIII.

As to the first, he excludes three ways. For we can falsely understand God to know many things in three ways: namely, either by positing that the divine intellect has a multitude of intelligences with a distinct esse; or by positing that the very forms understood subsist in themselves, and that God understands through them; or by positing that they have esse in a created intellect, and that God is thus understood through them. Therefore, in order to exclude these three imaginings, three conclusions are set down: the first and second are set down in this chapter; the third, in the following chapter ².

I. The first conclusion, therefore, is: Many things understood in God do not have distinct being in God. It is proved. Either those understood things would be the same as the divine essence, or they would be superadded to it. Not the first: because then there would be some multitude in the divine essence, namely an intrinsic one. Nor the second: because there would be some accident in God. Therefore, and so on.

Note that if there were many things with distinct esse in God, and they were really identical with the essence, they could not be compared to the essence itself except as its essential parts. And thus the essence itself would not be simple, but composed of parts, in the manner of material essences. For this reason Saint Thomas says that multitude would be posited in it, namely of essential parts.

II. The second conclusion is: Nor can forms of this kind, as understood, be posited to exist in themselves, so that the divine intellect might understand through them: as Plato posited, in order to avoid the aforementioned inconveniences.

It is proved first. The forms of material things cannot be understood without matter. Therefore much less can they exist without matter: which is, of course, the way they are actually understood.

Note that, although the Commentator, Metaphysics VII, comments 21 and 34, holds, as we said above in ³, that matter enters into the definition of material things only as that which conveys the essence, not as being of the essence of the thing, Saint Thomas nevertheless holds, in the First Part, question LXXV, article 4, and in Metaphysics VII, book 9, and in the treatise On Being and Essence ⁴, that matter is a part of the quiddity of a material thing. First, because the definition of natural things contains matter and form. Nor is matter placed in it as an addition to the essence: for it is proper to an accident to be defined by way of addition; or also to forms, which are parts. — Second, because matter belongs to the essence of all natural individuals. — Third, because this seems to be Aristotle's intention, who in Metaphysics VIII, texts 15 and 16 ⁵, posits a difference between the quiddities of composites and of simples with respect to unity, namely that the definition of composites is one because from act and potency it is naturally made to become one; but the quiddities of simples have their unity from themselves, since they are forms only. Ninthly, too, in Metaphysics, in the last texts ⁶, he says that in the quiddities of composites error occurs on account of the multitude of parts, which does not occur in simples, because of their lack of parts.

Therefore Saint Thomas says that the forms, that is, the quiddities, of natural things can neither be nor be understood without matter: namely, because nothing can be understood or be without that which pertains to its essence.

III. Second. If God were to understand by means of intelligible forms subsisting outside himself—supposing they existed—his perfection in understanding would depend on another. And consequently also in being, since his understanding is his esse. — The consequence is proved. For the perfection of the divine intellect requires that he understand a multitude of things. Therefore, if the forms by which he understands are outside himself, it follows that the perfection of his intellection depends on another.

Here two things must be noted. The first is that Saint Thomas does not say absolutely that the perfection of the divine intellect consists in the cognition of a multitude of things, but because this is required for the perfection of his intellect. For the perfection of divine intellection simply depends on the perfection of the first understood, which is the divine essence: just as in all other virtues the perfection of an operation is considered in relation to its first and principal object. But it is true that the perfection of the divine intellect requires that its intellection extend not only to its own essence, but also to the multitude of things: that is, that it have in itself that from which it can extend itself to the multitude of things. First, because the more an intellect extends itself in understanding, the more perfect it is. Second, because there would not be perfect knowledge of a cause unless the effects proceeding from it were known.

The second point is that the dependence of the intellect's perfection upon those subsistent forms can be understood in two ways. In one way, as upon a form eliciting the act of understanding: in the manner in which our understanding depends upon the intelligible species. In another way, as upon an object immediately terminating the act of understanding: in the manner in which our understanding has its perfection from a concept formed and produced by the intellect. In neither way can the perfection of the divine intellect depend upon the understood forms, since whatever is in God is most perfect from itself.

IV. But then a doubt arises. For it is not intelligible that any operation could be or be understood without its term of operation, in its own way, since every operation is terminated at some object. If, therefore, God understands a thing with respect to its proper esse which it has in nature, then such understanding could not be or be understood without the thing understood. Therefore the divine understanding necessarily depends on an extrinsic thing. And thus it will not even be unfitting for the divine understanding to depend on those subsisting forms as on an object.

2. For the clarification of this point, we must first consider that we must speak differently if we hold that God sees things other than Himself in His essence, and differently if we hold that God understands them as abstract and subsistent in themselves, as actually understood. For in the first way, things stand as secondarily understood, while the divine essence stands as the first and per se understood object. And since the operation of the intellect is specified and perfected by the first and per se object, and not by those things that are seen in the first and per se object, therefore the perfection of the divine intellect will not need to depend on other things, even though He sees other things in Himself. — But if we hold that God understands things as per se subsistent and actually understood, and not as contained in the divine essence, then they will have the character of the first and per se understood. And therefore the perfection of the intellect in understanding will depend on something extrinsic.

It must be considered, secondly, for a fuller explanation, that although a multitude of intelligibles is required for the perfection of the divine intellect, since the intelligible is understood according as it is in the intellect, this is nevertheless not to be understood with respect to the esse that they have in themselves, but with respect to the esse that they have in the divine essence understood. And because the esse that they have in the divine essence is the divine essence itself, therefore, when it is said that a multitude of intelligibles is required for the perfection of the divine intellect, it is not said that something distinct from God is required, but only the divine essence itself, which is the likeness of all intelligible things. Thus God indeed understands many intelligibles with respect to their proper existences and natures, yet they are not required for the perfection of the divine intellect with respect to the esse that they have in themselves, but with respect to the esse that they have in God. And so the divine intellect is not perfected by anything other than itself.

3. To the doubt, therefore, it is said that concerning the divine intellection by which God understands this thing, say a stone, we can speak in two ways: in one way, with respect to the intellection itself considered absolutely according to its own nature; in another way, insofar as it is the intellection of this thing. If it is considered in the first way, then it does not depend on this thing understood, but can even understand without it; for it is not specified by the stone, but by the divine essence understood first and per se. Now anything can be understood without that which is not of its essence. — If in the second way, then it is not unfitting for the divine cognition to depend on an extrinsic object. For when I speak of the divine intellection as the intellection of a stone, I speak of it together with a relation of reason to the stone. Now it is not unfitting for some relation of reason understood in God to depend on a creature as on its term, and to be unable to be understood without it: just as God cannot be understood as Lord of a creature unless the creature is understood.

V. Third. That God understand is presupposed, in the order of nature, to the existence of such intelligibles — if, I say, they are posited as subsisting. Therefore it is not by this that He understands many intelligibles, namely that they exist of themselves outside Him. — The antecedent is proved. For such forms will necessarily have to be caused by God, since everything that is besides its own essence is caused by Him, as will be shown below. But the cause of things is through intellect, as will also be shown.

It must be noted that Saint Thomas says that God understands these intelligibles as required by the order of nature for their esse, but he did not say by the order of time. For they could indeed have been produced from eternity, and thus one would not be prior to another in duration. Nevertheless it is always necessary that one precede by the order of nature: because a cause is naturally prior to its effect.

VI. Fourth. It would follow that the intellect of God would be in potency; and likewise the intelligibles themselves would be understood in potency. And thus it would need something to reduce them to act. — The consequence is proved. Because then the intellect is in act only when it is actually informed by an intelligible; and the intelligible is in act when it is one with the intellect; but when they are separate, each is in potency, as is also evident in the case of sense and the sensible.

But it seems that what Saint Thomas says is false, because, if those intelligibles are not in the divine intellect, they will be intelligibles in potency. For even if we grant that no intellect would understand separate substances, they would still be actually intelligible: because they are separate from matter.

It is answered that we can speak of the intelligibility of such forms in two ways: in one way, absolutely; in another way, in relation to this intellect. If we speak absolutely, they are actually intelligible even if they inform no intellect. But if we speak in relation to the divine intellect, then, if they do not inform it, they are potentially understood by it: just as an intellect that is not understanding something can indeed be actually understanding absolutely, namely by understanding something else, yet is not actually so with respect to those things it does not understand.

Fifth objection. The thing understood must be in the one understanding. Therefore it does not suffice to posit the forms understood outside God, in order that He may understand.

⁷ VII. The third conclusion is: A multitude of intelligibles cannot be posited in an intellect other than the divine, so that they may be understood by God. It is proved by the same arguments by which the preceding conclusion was proved. First, I say, because the divine intellect would then be in potency. — Second, because it cannot be that one intellect be disposed to act, namely by possessing the intelligible form, and another carry out the act; rather one and the same must both be disposed and carry it out; just as each thing is through its own essence, not through the essence of another.

Note that St. Thomas wished to compare the essence of a thing and the intelligible form proportionally in their order to esse and to understanding. For just as each thing has its own proper esse, so too it has its own proper operation. Therefore, as a thing is disposed with respect to esse, so is it disposed with respect to operation. Now the essence, which esse follows, is not in something other than the possessor of esse; rather, it is by its essence existing in itself that a thing is a thing. Therefore likewise the form, which understanding follows, is not in something other than the one understanding. — How the form, which is the principle of operation, must be in the one operating will be shown below ⁸