The true answer to this question is given by Plutarch in his treatise of reading of the poets. Plutarch attempts to prove, that youth is not to be prohibited the reading of the poets, but to be cautioned against such parts as may have bad effects. They are first to be prepossessed with this leading principle, that poetry is false and fabulous. He then enumerates, at length, the fables which Homer and other poets have invented about their deities, and concludes thus: “When, therefore, there is found in poetical compositions any thing strange and shocking, with respect to gods or demi-gods, or concerning the virtue of any excellent and renowned characters, he that should receive these fictions as truth, would be corrupted by an erroneous opinion; but he that always keeps in his mind the fables and allusions, which it is the business of poetry to contrive, will not be injured by these stories, nor receive any ill impressions upon his thoughts, but will be ready to censure himself, if, at any time, he happens to be afraid, lest Neptune, in his rage, should split the earth, and lay open the infernal regions.” Some pages afterwards, he tells us, “that religion is a thing difficult of comprehension, and above the understanding of poets; which it is,” says he, “necessary to have in mind when we read their fables.”
The pagans, therefore, had their fables, which they distinguished from their religion; for no one can be persuaded that Ovid intended his Metamorphoses, as a true representation of the religion of the Romans. The poets were allowed their imaginations about their gods, as things which have no regard to the publick worship. Upon this principle, I say, as I said before, there was, amongst the pagans, two sorts of religion; one a poetical, and the other a real religion; one practical, the other theatrical; a mythology for the poets, a theology for use. They had fables, and a worship, which, though founded upon fable, was yet very different.