In Freudian psychology, a term designating psychic or sexual energy.
The term libido, which Sigmund Freud used as early as 1894 and as late as the 1930s, underwent changes as he expanded, developed, and revised his theories of sexuality, personality development, and motivation. In Freud's early works, it is associated specifically with sexuality. Libido is central to the theory of psychosexual development outlined in Three Essays on the Theory of Sexuality (1905). It is the energy that is repeatedly redirected to different erogenous zones throughout the stages of pregenital sexuality (oral, anal, phallic) that take place between birth and the age of about five years. After the latency period, the libido reemerges in its mature manifestation at the genital stage that begins in adolescence. During all these permutations, the libido also shifts from being primarily autoerotic and narcissistic to being directed at a love object.
When Freud reformulated his theory of motivation around 1920, he defined libido more broadly in terms of opposed life and death instincts (Eros and Thanatos). Libido in this context is the source of the life instincts that motivate not only sexuality and other basic drives but also more complex human activities such as the creation of art.
Freud, Sigmund. New Introductory Lectures on Psychoanalysis. New York: W. W. Norton, 1933.
Hall, Calvin S. A Primer of Freudian Psychology. New York: Harper and Row, 1982.