" In the Louvre there is a picture, by Guido Reni, of St. Michael with his foot on Satan's neck. The richness of the picture is in large part due to the fiend's figure being there. The richness of its allegorical meaning also is due to his being there—that is, the world is all the richer for having a devil in it, so long as we keep our foot upon his neck. "

― William James , The Varieties of Religious Experience