Commentaria in Summam contra Gentiles, Liber I

The second conclusion that Saint Thomas posits is this: God knows Himself first and per se, and only Himself ¹.

I. For the understanding of which it must be noted that there is a twofold way in which something is said to be known first and per se. One is that it be known as the formal object under which all things are referred to a power. For, since a power is directed toward several objects, as sight toward several colors, and one power is not directed toward several things insofar as they are several, those things must converge in some one thing containing and unifying them all. And this is what is called the first and per se object of the power: because none of those many things is attained by the power except insofar as it participates in that one thing; just as neither white nor black is seen except insofar as they are colored. — The other way is that something be known not through another known thing in which it is known, but that it itself be apprehended by the power according to itself. In this way white is said to be seen first and per se when it is not seen through another visible thing.

In both ways the divine essence is the first and per se object of the divine intellect: and because, I say, it is comprehended by that intellect not through any other rationale that it might share in, but is understood through itself by its own rationale, and all other things are understood by the divine intellect insofar as they are united, through a certain participation, to the rationale of the divine essence; and because it is understood according to itself, but not in something else understood. Yet although it is understood in both ways as first and per se, nevertheless the second way seems to be what is intended here: because it is compared to other things known first and per se, just as in other intellects several things can be found known first and per se; now this is clearly true in the second sense, but not in the first, since from the unity of that first and per se object the power is one. That this is also the mind of Saint Thomas appears manifestly here from the arguments adduced.

II. But the conclusion is proved first. That by which God understands is nothing other than the divine essence. Therefore what is understood by Him, first and per se, is nothing other than Himself. — The consequence is proved. Only that is known first and per se by an intellect whose species it understands, because the operation must be proportioned to the form which is the principle of the operation.

It must be noted concerning that proposition, "That which the intellect first and per se knows is that whose species it understands"; and its proof: since every agent acts upon what is like itself, and every knower knows what is like itself, because like is known by like, the operation must be terminated at that which is like the formal principle of the operation. And this is what it means for the operation to be proportioned to the form which is the principle of the operation, namely, that it is terminated at what is like the form from which the operation is elicited or specified.

2. But because, as we said ², something can be called first and per se known in two ways, this proposition as assumed can have a twofold truth. For if we wish to take the first and per se known in the first way, it must be considered that the form which is the principle of operation can be considered in two ways: namely, materially and formally. For just as on the side of the object there are material objects, namely the particular natures to which the operation of the power is terminated, and a formal ratio in which all of them agree—as in sight the material objects are whiteness and blackness and the other specific colors, while the formal one is color, because all colors are referred to sight insofar as they are colors—so on the side of the form which is the principle of operation, the material is the form of this particular thing insofar as it is this form, and the form of that insofar as it is particularly that one's; while the formal is the common ratio in which all the forms of such a power agree, and by which the power operates first and per se; just as the form of whiteness in sight, as the particular likeness of whiteness, and the form of blackness as the form of blackness, is the form of material sight; but that which I call the likeness of color, in which all the forms of sight agree, is the formal in them, and by it sight sees first and per se. So also on the side of the intellect, although in one intellect there are species and likenesses of diverse natures, those, considered according to particular rationes, are material forms: but that in which all the species of that intellect agree is the formal, and what is represented to the intellect through it is first and per se known. Thus, because all the species of our intellect agree in this, that each is a species of material quiddity, speaking of the proportionate object, or of being, speaking of the adequate object; therefore the species of our intellect, taken formally, by which it understands first and per se, is the species of natural quiddity or the species of being. And so what is said here, that that is first and per se known by the intellect whose species it understands by, must be understood of the species taken formally, by which it understands first and per se.

The divine essence is related to the divine intellect in this way: it is the form by which the divine intellect understands first and per se. Indeed, it has this further property, that it is not multiplied into many material species, as the species of our intellect are; rather it remains one in number, and represents nothing to the divine intellect except insofar as it is the divine essence, either formally or participatively. Therefore what is known first and per se by the divine intellect is the divine essence itself and God himself.

3. But if the first and per se known is taken in the second way, as we have said it is taken here by Saint Thomas, then it is understood that that thing is known first and per se by that intellect whose species, as the first thing representing it, represents it—not, however, representing another prior thing in which it shines forth. And because the species by which the divine intellect knows first and per se represents the divine essence, while other things are known as shining forth in the divine essence, and there is no other species in the divine intellect, therefore he alone is known first and per se by himself.

III. Second: and the argument is taken from Metaphysics XII, text 51 ³ If it were not so, then the divine intellect would be changed from the consideration of itself to the consideration of another. And since that other would be less noble than itself, it would be changed for the worse. — The consequence is proved. Because it is impossible for what is first and per se to understand several things at once, since a single operation cannot be terminated at once by many terms. Therefore, since God at some time understands himself, if he understood something else as first and per se understood, his intellect would be changed from the consideration of himself to the consideration of another.

Note that this argument presupposes, from what precedes, that God first and per se understands himself; it proves, however, that he understands nothing else first and per se.

2. But two doubts arise. The first is that it seems that one operation can be terminated first and per se in diverse terms. For the same heating by the sun melts wax and hardens clay.

Second, concerning the argument. For someone might say that from the fact that the divine intellect understands something other than itself, it does not follow that it ceases from the intellection of itself. For an angel too, while always understanding itself, as will be shown below ⁴, also understands other things first and per se, in the sense of the conclusion.

3. To the first it is answered that that operation, although it is one on the side of the active principle formally, and therefore proceeds from one form, is nevertheless virtually several, and is multiplied on the side of the passive principles: for each of these receives it in its own way.

To the second it is answered that an angel, although it understands other things, does not cease from the knowledge of itself, because it understands other things through species superadded to its own essence; and consequently it can have several intellections at once, terminated first and per se to different objects. Therefore it is not necessary that, while it understands other things, it cease to understand itself. God, however, understands by His essence alone, as was shown above ⁵. And consequently He cannot have several intellections at once: for by one form several operations are not produced simultaneously by one agent. Therefore, since many things cannot be understood by a single intellection in such a way that each is understood first and per se, it is necessary, if God understands Himself and likewise something other than Himself, that this occur through successive intellections; and consequently, if He understands something other than Himself first and per se, He must cease to understand Himself.

IV. Third. If God understands himself and another thing as his principal object, he will have several intellectual operations, since the operations of the intellect are distinguished by their objects. Therefore either his essence will be divided into several things, if—I say—the understanding is the same as his essence; or he will have some act of understanding that will not be his substance. Both of which are impossible.

Note that, although all the operations of one power look to one formal ratio, by reason of which they are all said to be of the same ratio, they are nevertheless multiplied materially by the plurality of material objects, when each of them is attained per se by the power, and not one as united to another; just as the vision of white is one thing, that of black another, when each is seen per se. Hence at this point, when it is said that operations are distinguished according to objects, this is understood of those objects to which the operation terminates altogether per se and distinctly, and of a real distinction of operations.

V. Fourth. The divine intellect would be in potency with respect to something else. — The consequence is proved. Because an intellect that differs from its intelligible object is in potency with respect to that object.

Fifth. There would be something other than the perfection of the divine intellect, and nobler than it. — The consequence is proved. Because the intellect, namely the first intellect, which is understood through its own species, is a perfection of the one understanding; and consequently, as such, it is more perfect by it. For an intellect is perfect, namely in the ultimate degree of perfection, by the fact that it understands in act. But this it has from being one with that which is understood, namely as informed by it.

Sixth. God's knowledge would be composite. And thus God's essence would be composite, if God's knowledge is the same as his essence; or knowledge will be an accident in God. — The consequence is proved. Because knowledge is made up of many things understood primarily and first.

It must be noted that knowledge, insofar as it signifies an ordered collection of intelligible species, signifies a certain unity by aggregation and something composite. Therefore, where many things are known by some intellect through diverse species, that knowledge has composition and multiplicity. But this occurs where many things are understood first and per se: for then each thing is not understood through the species of another, but through its own proper and adequate species. Therefore, if many things were known first and per se by God, God's knowledge would have composition and multiplicity.

Seventh. If there were something else known by God first and in itself, God's understanding would have its species and nobility according to that which is other than itself. But this is impossible, since His operation is His essence. — The consequence is proved: because understanding has its species and nobility according to what is understood first and in itself, since this is its object.

It must be known that, although a single act of understanding can be terminated at many things at once insofar as one is contained in the other, nevertheless that which is represented first and immediately by the intelligible species as by its proper species is said absolutely to be the object of such an operation and known first and per se; but not those things that are represented secondarily, as contained in the first and principal object. Just as if someone sees a mirror in which many images appear, what is first and per se known and seen is the mirror itself, not those things that are seen in it: and it is specified by it, not by the things seen in it; for it is called absolutely the vision of the mirror, while of the others it is said to be vision in the mirror. On account of this Saint Thomas says that an act of understanding has its species and nobility according to what is first and per se known, because that is its object—namely, that which is said simply and absolutely to be the object of the act of understanding.