What we believe to be the motives of our conduct are usually but the pretexts for it. - Miguel de Unamuno, Tragic Sense of Life. Self-deception is common and universal, and the cause of most human tragedies. Of course, the science of self-deception can help us to live better and get more out of life. But it can also cast a murky light on human nature and the human condition, for example, on such exclusively human phenomena as anger, depression, fear, pity, pride, dream making, love making, and god making, not to forget age-old philosophical problems such as selfhood, virtue, happiness, and the good life. Nothing could possibly be more important.