Anyone seeking to understand their own mind or that of other people should have this groundbreaking book. In one of his most important writings, Freud brings the id, the secret source of human passion, out from the shadows, and explains how it remains in constant conflict with the ego and the superego. He suggests that the complex interactions of these three parts of the mind are the source of all human behaviors and personality traits. Sigmund Freud founded the field of psychoanalysis and pioneered the use of the unconscious for treating mental disorders. Almost 100 years after his death, his ideas remain influential in psychotherapy, psychology, and psychiatry.