And so a rightly directed will is love in a good sense and a perverted will is love in a bad sense. Therefore a love which strains after the possession of the loved object is desire; and the love which possesses and enjoys that object is joy. The love that shuns what opposes it is fear, while the love that feels that opposition when it happens is grief. Consequently, these feelings are bad, if the love is bad, and good if the love is good.
Augustine, The City of God, tr. by Henry Bettenson (New York: Penguin, 2003), 557 (14.7).