Commentaria in Summam contra Gentiles, Liber I

After Saint Thomas had determined concerning the first and per se object of divine cognition, he now determines concerning the secondary object¹. Concerning this, however, he does two things: first, he determines concerning such an object in general; second, in particular, chapter LXIII. Concerning the first, he does two things: first, he treats of the object known per se; second, of the object concomitant to the object known, namely truth, chapter LIX.

Concerning the first, he does two things: first, he treats of the object known; second, of the mode of its cognition, in the following chapter.

I. As to the first, the following conclusion is proposed: God knows things other than himself.

And it is proved first as follows. God knows His essence most fully. Therefore He knows things other than Himself. — The consequence is proved: because the knowledge of an effect is sufficiently had through the knowledge of its cause; hence we are said to know each thing when we know its cause. But God, through His essence, is the cause of being for others. Therefore, etc.

It must be noted that in this conclusion the mode of cognition is not determined—namely, whether God knows other things perfectly or imperfectly—but the matter concerns cognition of other things absolutely, whether they are known perfectly or imperfectly. Hence from this argument it is concluded absolutely that God knows things other than himself. And what Saint Thomas says—that since an effect is sufficiently known from the knowledge of its cause—is to be understood as follows: that sufficiency does not signify perfection of cognition, but the exclusion of the necessity of anything else; for in order to have cognition of an effect absolutely, if the cause is known insofar as it is a cause, or with respect to the power by which it is a cause, nothing else is required.

Second. That which is in something in an intelligible manner is understood by it. But the things caused by God are in him intelligibly. Therefore, etc. — The major is supposed to be true. — The minor, however, is proved: as to its first part, because, since every agent acts in a manner like itself, the likeness of every effect preexists in some way in its cause; as to its second part, because everything that is in something is in it according to the mode of that in which it is, and God, by his nature, is intellectual.

Third. God knows that He is a cause. Therefore He knows in some way the caused. Therefore things other than Himself: for He is not the cause of Himself, but of something else. — The antecedent is proved. For whoever knows a thing knows all that can truly be said of it and what belongs to it according to its nature. But God knows Himself perfectly; and according to His nature it belongs to Him to be the cause of other things. Therefore, and so on.

Concerning the assumption made in the proof of the antecedent, it must be considered that Saint Thomas fittingly added, and those things that belong to it according to nature: because one who knows a thing perfectly need not know all things simply that are naturally apt to accrue to it from an extrinsic cause and can be truly predicated of it; but only those that can be truly predicated of it as belonging to it according to nature. On this account that proposition is to be taken conjunctively, not divisively.

Regarding that proposition, it belongs to God by nature to be the cause of other things, it must be noted that it can bear a twofold sense. One is that the divine nature, taken formally, is the immediate principle of acting. And this sense is not intended here, but is false: for it would signify that God acts by necessity of nature, not through intellect. — The other, that the nature be signified as the remote foundation of causality: just as if we were to say that man understands by nature, not because his nature and essence are the immediate principle of intellection, but because they are the remote principle and foundation from which he has it that he understands. And this sense is true, and this is what Saint Thomas intends. For that God is the cause of all other things through intellect belongs to him originally and fundamentally from the perfection of his nature.

It should also be noted that this argument differs from the first: for in this one the power of the cause is considered in its relation to its effect, which is meant to be understood when it is said that God knows Himself to be a cause; but in the first, the power and perfection of the cause are considered absolutely.

II. From this conclusion and the preceding one, a corollary is drawn: that God knows Himself as first and known through itself, but other things as seen in His essence.

This is also confirmed by the authority of Dionysius, chapter 7 of De Divinis Nominibus. And in the Psalm it is said: He looked down from his holy height, as it were seeing other things from himself.

III. Concerning this corollary, and also the conclusion, a doubt arises: how does God see other things only in Himself, since things have esse distinct from Him, and to know such things in another is to know imperfectly?

2. For the evidence of this, it must be considered that the effects of God, as is said in Verit., q. viii, a. 4, are not contained in the divine essence as the images of things are contained in a mirror: because things contained in a mirror are distinct and multiple, having real distinction from one another in the mirror; but the effects of God are not contained divisively and multiply in the divine essence. Rather, they are contained as effects in a cause producing all things by a single power: in which power the effects are not present divisively and multiply, but unitedly in one power eminently containing all, so that all of them are that very power, indivisible and simple. Therefore to know God is not to see things in their essence as in a mirror, which would be to see them with a certain distinction existing in that in which they are seen: rather, it is to see them as in a cause, which is to see them in one indivisible essence containing all things unitedly and eminently and representing all things most perfectly. And if it is sometimes found said by the saints that the divine essence is a mirror, this must be understood in some respect, namely insofar as all things are seen in it: not, however, according to the mode of existing of things in a mirror.

3. But that things other than God are seen in Him can be understood in two ways. In one way, so that things are seen in the divine essence only with respect to the esse they have in it. And this is not what we mean here: for, since that esse of things is nothing other than the divine esse, to know things in this way would be to know only the divine esse. — In another way, so that in the divine essence there is seen not only the esse of things which they have in it, but also the esse which each thing has in itself, inasmuch as the divine essence is an expressed likeness of all things with respect to all that is in them: just as, if the image in a mirror were to represent all that is in a thing, including the particular esse the thing has in itself, then from the vision of that image the thing itself would also be seen perfectly.

From which it follows that what some say—namely, that God knows other things terminatively—can be understood in two ways. Terminatively in one way, as meaning the same as the divine intellect being extended by its act to the esse of things as they have it in themselves, whether immediately or mediately. And in this sense it is true that God knows things terminatively. — In another way, as meaning that the divine intellect is terminated immediately to things as they are in themselves, so that their esse is not seen in something else known in which they are represented. And in this sense God does not know them terminatively: for He is terminated to them as they are in themselves only secondarily and through the divine essence, in which they are seen as represented by it.

4. But what Aristotle seems to say, in XII Metaphysics, text 51 ², namely that God knows only Himself and not other things outside Himself, is no obstacle. For it can be understood in two ways that God understands something outside Himself. In one way, because He understands something that is other than Himself. And in this way God does understand something outside Himself. — In another way, because He knows something other than Himself first and in itself, and not in God Himself. And in this way He does not understand something outside Himself; rather, everything He knows He understands by seeing His own essence. This is how Aristotle understood it.

This also seems to be what the Philosopher intends in the same place: that the divine intellect would be debased if it knew things below itself. It is understood similarly, if it were to know those things as its first and per se object, while not knowing itself. For then God's knowledge would terminate in a base object, whereas the intelligence moving the sphere would know God himself, which is the most noble object of knowledge. And thus the divine intellect would be debased, since it would terminate in lower things, passing over the most noble being. — That this is Aristotle's meaning there is evident, because he said this in answering that question by which it was asked whether he knows himself or other things. And he answers that he does not know other things, namely alone, but knows himself as the first thing known, etc.: because, if he knew only things other than himself, his knowledge would be base among the cognitions of the other intelligences. — It can also be said that, if he were to know things other than himself through a change from the intellection of himself to the intellection of other things, he would indeed be debased: for then he would pass from what is more noble to what is less noble.

5. To the doubt, therefore, it is said that although things, insofar as they are in themselves, have an esse distinct from God, nevertheless they are seen imperfectly because they are seen in the divine essence. For when something is seen in something else that represents it perfectly with respect to all things, such that through that other thing the vision is secondarily terminated at the proper esse of the thing itself, then it is not known imperfectly; rather, it is known most perfectly. But it would indeed be known imperfectly if either that other thing were not its perfect likeness, or if the gaze rested only in that likeness itself and were not terminated at the thing itself.

It must be noted, however, that when the divine cognition is said to be terminated secondarily to things, we do not by this intend to posit an order in the divine cognition itself considered in itself, but only among the things known. And the sense is that some things are secondary objects of the divine cognition.