Commentaria in Summam contra Gentiles, Liber I

After Saint Thomas has determined the divine goodness absolutely, he now determines it comparatively ¹. Concerning this, however, he does two things: first, he compares the divine goodness to other goods by way of principle; second, by way of excellence, in the following chapter.

As to the first, he posits this conclusion: God is the good of every good.

For the understanding of which it must be known, from the teaching of St. Thomas in the Prima, q. 6, a. 4, and De Veritate, q. 21, a. 4, ad 3, that God can be understood to be the good of every good in two ways. In one way, intrinsically: namely, because He Himself, in Himself, is the goodness inherent in things, by which each thing is said to be good. And it is not taken in this way here: for it was shown above ² that God is the form of no thing. — In another way, extrinsically, by the mode of an efficient, exemplar, and final principle. And it is understood in this way: namely, because the goodness of any creature whatsoever is produced and exemplated by God, and is ordered to Him as to its end.

It is proved, first. In God are the perfections of all things. Therefore He comprehends all goods, and is the good of every good. — The consequence is proved. Because the goodness of a thing is its perfection.

Second. All things have a likeness of the divine goodness. Therefore, etc. — The antecedent is proved. Because God is good through essence, but other things through participation: now that which is such through participation is such because it has some likeness of that which is such through essence.

It must be noted here that for something to be said to be such participatively, it is not required that it possess that thing according to the same univocal account according to which it is in that which is said to be such by essence; rather, it suffices that it have some likeness of it, as Saint Thomas holds in this place.

Third. God is the ultimate end of all things, as will be shown below. Therefore He is the good of every good. — The inference is proved: since good has the character of the appetible, and each thing is appetible on account of an end, each thing is called good either because it is an end or because it is ordered to an end. Therefore the ultimate end is that from which all things have the character of good.

The conclusion is confirmed by the authority of Exodus 33 and Wisdom 7.