City of God

This I do know, that the nature of God can never, nowhere, nowise be defective, and that natures made of nothing can. These latter, however, the more being they have, and the more good they do (for then they do something positive), the more they have efficient causes; but in so far as they are defective in being, and consequently do evil (for then what is their work but vanity?), they have deficient causes. And I know likewise, that the will could not become evil, were it unwilling to become so; and therefore its failings are justly punished, being not necessary, but voluntary.

For its defections are not to evil things, but are themselves evil; that is to say, are not towards things that are naturally and in themselves evil, but the defection of the will is evil, because it is contrary to the order of nature, and an abandonment of that which has supreme being for that which has less. For avarice is not a fault inherent in gold, but in the man who inordinately loves gold, to the detriment of justice, which ought to be held in incomparably higher regard than gold. Neither is luxury the fault of lovely and charming objects, but of the heart that inordinately loves sensual pleasures, to the neglect of temperance, which attaches us to objects more lovely in their spirituality, and more delectable by their incorruptibility.

Nor yet is boasting the fault of human praise, but of the soul that is inordinately fond of the applause of men, and that makes light of the voice of conscience. Pride, too, is not the fault of him who delegates power, nor of power itself, but of the soul that is inordinately enamored of its own power, and despises the more just dominion of a higher authority. Consequently he who inordinately loves the good which any nature possesses, even though he obtain it, himself becomes evil in the good, and wretched because deprived of a greater good.