A Psychology of
Human kind cannot bear very much reality.
-- T. S. Eliot
We need lies in order to live.
In this text, I have examined widely varied aspects of lying, both to oneself and to others. Deceit is a prevalent--perhaps even central--part of life ( Elaad 1993) that has received, in relation to its importance, comparatively little scientific investigation. I have proposed a biological approach to deceit, consistent with the theoretical formulations of scientists such as Robert Trivers. We must also consider the sociological meanings of deception (because lying is basically a social phenomenon), as well as its intrapsychic functions. Developmental issues of how we learn to lie and to detect lying are an integral part of the process of maturation.