Saint Augustine, The City of God, Vol. II

But it had to be insinuated that the scriptures of our religion, whose authority we place before all other writings, do not call love one thing and affection or charity another. For
5 we have already shown that love is also used in a good sense. But lest anyone think that "love" is used in both evil and good, but "affection" is only to be said in the good, let him attend to that which is written in the psalm: But he who loves original: "diligit" iniquity, hates his own soul, and that of the apostle John:
10 If anyone has loved original: "dilexerit" the world, the love original: "dilectio" of the Father is not in him.
Behold, in one place "affection" is in both good and evil. But lest anyone
demand "love" in the evil (because we have already shown it in the good), let him read what is written: For men will be lovers of themselves, lovers of money. A right
15 will, therefore, is a good love, and a perverse will is an evil love. Love, therefore, panting to have what is loved, is desire, but having it and enjoying it is joy; fleeing what is adverse to it, is fear, and if it happens, feeling it is sadness. Therefore, these are evil if the love is evil;
20 good if the love is good. Let us prove what we say from the scriptures. The apostle desires original: "Concupiscit" to be dissolved and to be with Christ; and: My soul has desired original: "Concupivit" to long for your judgments, or if it is said more fittingly: My soul has longed to desire original: "concupiscere" your judgments; and: The desire original: "Concupiscentia" of wisdom leads to
25 the kingdom. Yet the custom of speaking has obtained that if "desire" or "longing" is mentioned and it is not added of what thing it is, it cannot be understood as anything but evil. Joy is in the good: Rejoice in the Lord and exult, you just; and: You have given joy to my heart; and: You will fill me with joy with
30 your countenance. Fear is in the good according to the apostle, where he says: