Commentaria in Primam Partem Summae Theologiae

A clear title. – In the body, two points. First, he responds directly to the question in the affirmative: God is supremely eternal. It is proved. God is supremely immutable; therefore He is supremely eternal. – The inference is proved: because eternity follows upon immutability, just as time follows upon motion.

II. Second, the manner in which God is eternal is assigned by positing another conclusion, namely: God is His own eternity. For this is to say that He is not eternal denominatively, but essentially. – This conclusion he first shows to contain within itself a certain singular excellence of God; second, he proves it; third, he explains it.

For since eternity is a species of duration, in saying that God is his own eternity it is also said that he is his own duration. This, however—that a thing should be its own duration—is singular in God: for it is said to belong to no other in the letter.

The conclusion is then proved, together with the singularity contained within it. God is His own uniform esse, and nothing other than God is its own esse: therefore He alone is His own duration, which in Him is eternity.

It is finally declared by way of similitude: because just as it is its essence, so too is it its eternity.

III. Concerning the force and meaning of the proof of the second conclusion, note that res is here taken for a subsistent thing, to which, strictly speaking, there belongs only esse. Thus the text does not intend that every thing other than God be distinguished from its duration, since time is not distinguished from it; rather, it intends that no thing which both is what it is and endures is its own duration. The force of the argument consists in this: since a thing, its esse, and its duration are related in a certain order (for duration does not belong to a thing except through esse as mediator; for a thing does not endure except by reason of its esse; because, namely, it retains esse, every thing endures, and on account of nothing else): when, I say, this is so, it follows that if one of the extremes is not identical with the middle term, then neither is it identical with the other extreme; for the extremes stand farther apart from each other than from the middle. Now an enduring thing other than God, which is one extreme, is not identical with its esse, as we have supposed. Therefore neither is it identical with its duration, which is the other extreme.

IV. Concerning the same proof, a doubt from Aureol, as reported by Capreolus, in the ninth distinction of the First Book¹, arises. For he attacks what is said implicitly there, namely that God's eternity is formally duration. Since every duration, when compared to another, is greater, lesser, or equal: eternity is not of this kind. It is proved: because it cannot be understood to be greater, with "before" post or "after" ante excluded, in lasting longer; therefore every greater duration has "before" ante or "after" post; which is repugnant to eternity.

V. To this, briefly, one can reply in two ways. First, by denying the minor. And in answer to the proof, it is said that to include a greater duration before and after within itself can happen in two ways: in one way formally, in another way virtually and eminently, just as heat is in the sun; and that eternity, which is greater than the others, is truly said of it that it endures before or after some time, because it possesses these beforehand within itself eminently. – Second, one can reply, strictly speaking, by denying the major. For comparison properly occurs only among things of one and the same nature; but eternity is a duration of a nature altogether different from time. And this is so speaking of it in itself: although, conceived as coexisting, eternity is compared with time even by illustrious men.

VI. In response to the first, note two things. First is that, just as a moving point is said to cause a line, and yet it does not cause that line to be in any genus of cause; and therefore it is not the cause of the line in real being, but is its cause in cognized being, because it produces knowledge of it in us: so too a standing now is said to cause eternity, not in real being, but in cognized being, because it causes the concept of it in us. And just as it is impossible for a point to move, and yet we conceive and say that a point moved—that is, if it were moved—would cause a line: so, given that it is impossible for the now to stand still, nevertheless we say very well that a standing now makes eternity, that is, if it stood still, it would constitute eternity.

Second is that from this it is evident how vain was the labor of Aureol's arguments against us, where above², in attacking this saying of Boethius and St. Thomas, because the now cannot be conceived as standing still, and in removing the now from God. For he equivocates concerning the now, indeed he presupposes that only the now of time is given: whereas the now of eternity is of another account than the now of time. And again, as was said, the very now of time, if it stood still, would constitute eternity: just as a point, if it were moved, would make a line. Therefore I judged it unnecessary to bring forward his objections: for they are most easily resolved by these considerations.