386–429 · Augustine of Hippo, Letters 118.13
If, then, you have learned that neither the supreme good nor any part whatever of the supreme good is in the body, the remaining alternatives are, that it is in the mind, or in God, or in both combined. And if now you have also learned that what is true of the body in this respect is equally true of the mind, what now remains but God Himself as the One in whom resides man’s supreme good?—not that there are no other goods, but that good is called the supreme good to which all others are related. For every one is blessed when he enjoys that for the sake of which he desires to have all other things, seeing that it is loved for its own sake, and not on account of something else. And the supreme good is said to be there because at this point nothing is found towards which the supreme good can go forth, or to which it is related. In it is the resting-place of desire; in it is assured fruition; in it the most tranquil satisfaction of a will morally perfect.