(CG 3/18). How God is the End of all Things (Book 3. God, the End of Creatures) (Summa Contra Gentiles) (Aquinas, Thomas, St.)

All things evidently have a natural appetite for being, and resist destructive agencies wherever they are threatened with them. But all things have being inasmuch as they are likened to God, who is the essential subsistent Being, all other things having being only by participation. All things therefore have an appetite for likeness to God, making that their last end.

4. All created things are some sort of image of the prime agent, God: for every agent acts to the production of its own likeness: now the perfection of an image consists in representing its original by likeness thereto: the image in fact is made on purpose. All things then exist for the attaintment of the divine likeness; and that is their last end.