Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 24

Chapter 24.—The Reasons by Which the Pagans Attempt to Defend Their Worshipping Among the Gods the Divine Gifts Themselves.

We may, however, consider their reasons.  Is it to be believed, say they, that our forefathers were besotted even to such a degree as not to know that these things are divine gifts, and not gods?  But as they knew that such things are granted to no one, except by some god freely bestowing them, they called the gods whose names they did not find out by the names of those things which they deemed to be given by them; sometimes slightly altering the name for that purpose, as, for example, from war they have named Bellona, not bellum; from cradles, Cunina, not cunæ; from standing corn, Segetia, not seges; from apples, Pomona, not pomum; from oxen, Bubona, not bos. Sometimes, again, with no alteration of the word, just as the things themselves are named, so that the goddess who gives money is called Pecunia, and money is not thought to be itself a goddess:  so of Virtus, who gives virtue; Honor, who gives honor; Concordia, who gives concord; Victoria, who gives victory.  So, they say, when Felicitas is called a goddess, what is meant is not the thing itself which is given, but that deity by whom felicity is given.