Freud said to me, “My dear Jung, promise me never to abandon the sexual theory. That is the most essential thing of all. You see, we must make a dogma of it, an unshakable bulwark.” . . . In some astonishment I asked him, “A bulwark against what?” To which he replied, “Against the black tide of mud”— and here he hesitated for a moment, then added— “of occultism.” C. G. Jung, Erinnerungen, Träume, Gedanken, 1963