Truth and deception - like good and evil - have long been viewed as diametrically opposed and unreconcilable. Yet, few people can honestly claim they never lie. In fact, deception is practiced habitually in day-to-day life - from the polite compliment that doesn't accurately relay one's true feelings, to self-deception about one's own motivations. What fuels the need for people to intricately construct lies and illusions about their own lives? If deceptions are unconscious, does it mean that we are not responsible for their consequences? Why does self-deception or the need for illusion make us feel uncomfortable? Taking into account the sheer ubiquity and ordinariness of deception, this interdisciplinary work moves away from the cut-and-dried notion of duplicity as evil and illuminates the ways in which deception can also be understood as an adaptive response to the demands of living with others. The book articulates the boundaries between unethical and adaptive deception, demonstrating how some lies serve