37 Let us examine, then, what is said in this way. In the grove of Henna, my opponent says, the maiden Proserpine was once gathering flowers: this is as yet uncorrupted, and has been told in a straightforward manner, for all know without any doubt what a grove and flowers are, what Proserpine is, and a maiden. Summanus sprung forth from the earth, borne along in a four-horse chariot: this, too, is just as simple, for a team of four horses, a chariot, and Summanus need no interpreter.
Suddenly he carried off Proserpine, and bore her with himself under the earth: the burying of the seed, my opponent says, is meant by the rape of Proserpine.What has happened, pray, that the story should be suddenly turned to something else? That Proserpine should be called the seed? That she who was for a long time held to be a maiden gathering flowers, after that she was taken away and carried off by violence, should begin to signify the seed sown? Jupiter, my opponent says, having turned himself into a bull, longed to have intercourse with his mother Ceres: as was explained before, under these names the earth and falling rain are spoken of I see the law of allegory expressed in the dark and ambiguous terms.
Ceres was enraged and angry, and received the parts of a ram as the penalty demanded by vengeance: this again I see to be expressed in common language, for both anger and (testes and) satisfaction are spoken of in their usual circumstances. What, then, happened here—that from Jupiter, who was named for the rain, and Ceres, who was named for the earth, the story passed to the true Jove, and to a most straightforward account of events?
Source: Against the Heathen (New Advent)