On The Holy Trinity by St. Augustine
Chapter 8.--In What Desire and Love Differ.
[Conceived] therefore, either by desire or by love: not that the creature ought not to be loved; but if that love [of the creature] is referred to the Creator, then it will not be desire (cupiditas), but love (charitas). For it is desire when the creature is loved for itself. And then it does not help a man through making use of it, but corrupts him in the enjoying it. When, therefore, the creature is either equal to us or inferior, we must use the inferior in order to God, but we must enjoy the equal duly in God. For as thou oughtest to enjoy thyself, not in thyself, but in Him who made thee, so also him whom thou lovest as thyself. Let us enjoy, therefore, both ourselves and our brethren in the Lord; and hence let us not dare to yield, and as it were to relax, ourselves to ourselves in the direction downwards. Now a word is born, when, being thought out, it pleases us either to the effect of sinning, or to that of doing right. Therefore love, as it were a mean, conjoins our word and the mind from which it is conceived, and without any confusion binds itself as a third with them, in an incorporeal embrace.