'Man has no choice about his capacity to feel that something is good for him or evil, but what he will consider good or evil, what will give him joy or pain, what he will love or hate, desire or fear, depends on his standard of value. If he chooses irrational values, he switches his emotional mechanism from the role of his guardian to the role of his destroyer. The irrational is the impossible; it is that which contradicts the facts of reality; facts cannot be altered by a wish, but they can destroy the wisher. If a man desires and pursues contradictions — if he wants to have his cake and eat it, too — he disintegrates his consciousness; he turns his inner life into a civil war of blind forces engaged in dark, incoherent, pointless, meaningless conflicts (which, incidentally, is the inner state of most people today).'
-- Ayn Rand