Summa contra Gentiles1.40 Chapter XL. That God is the good of every good3

It is also proved from the foregoing that God is the good of every good..

For the goodness of a thing is its perfection, as we have stated. Now, since God is simply perfect, He contains in His perfection the perfections of all things, as we have shown. Therefore His goodness contains all goodnesses; and consequently He is the good of every good.

Again. A thing is not said to have a quality by participation, except in so far as it bears some resemblance to that which is said to have that quality essentially: thus iron is said to be fiery in so far as it partakes of a resemblance to fire. Now, God is good essentially, while all else is good by participation, as we have proved. Therefore nothing is said to be good except in so far as it bears some resemblance to the divine goodness. Therefore He is the good of every good.

Further. Since a thing is desirable for the sake of an end, and the aspect of good consists in its being desirable;

it follows that a thing is said to be good, either because it is an end, or because it is directed to an end. Therefore the last end is that from which all things take the aspect of good. Now this is God, as we shall prove further on. Therefore God is the good of every good.

Hence the Lord in promising Moses that he should see Him, said (Exod. xxxiii. 19): will show thee all good. And it is said of divine wisdom (Wis. viii.): All good things came to me together with her.