On Christian Doctrine 58No Help is to Be Despised, Even Though It Come from a Profane Source.

28. But whether the fact is as Varro has related, or is not so, still we ought not to give up music because of the superstition of the heathen, if we can derive anything from it that is of use for the understanding of Holy Scripture; nor does it follow that we must busy ourselves with their theatrical trumpery because we enter upon an investigation about harps and other instruments, that may help us to lay hold upon spiritual things. For we ought not to refuse to learn letters because they say that Mercury discovered them; nor because they have dedicated temples to Justice and Virtue, and prefer to worship in the form of stones things that ought to have their place in the heart, ought we on that account to forsake justice and virtue. Nay, but let every good and true Christian understand that wherever truth may be found, it belongs to his Master; and while he recognizes and acknowledges the truth, even in their religious literature, let him reject the figments of superstition, and let him grieve over and avoid men who, "when they knew God, glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened. Professing themselves to be wise, they became fools, and changed the glory of the uncorruptible God into an image made like to corruptible man, and to birds, and four-footed beasts, and creeping things."