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. In the religious consciousness, that is just the position in which the fiend, the negative or tragic principle, is found; and for that very reason the religious consciousness is so rich from the emotional point of view.
James, William. Varieties of Religious Experience, a Study in Human Nature (p. 20). Public Domain Books. Kindle Edition.