Freud, Sigmund (1856–1939), the Austrian physician who founded psychoanalysis. Psychoanalysis is a method of studying and treating mental illness by probing the unconscious part of the personality.

Freud has been criticized because he did not use the experimental methods of science, and he has been accused of overemphasizing the part that the sex urge plays in an individual's life. Some of his students —notably Carl Gustav Jung and Alfred Adler —broke away to found their own schools. Nevertheless, Freud's theories influenced medicine, psychology, and education. They have been applied in the analysis of art, humor, myth, and religion, and have influenced many writers (James Joyce, for example) and artists (such as the Surrealists). Ego, catharsis, repression, and other Freudian terms became part of everyday speech. New significance was attached to the meaning of dreams and to slips of the tongue.

Sigmund Freud was born in what is now the Czech Republic. His parents, middleclass Jews, moved to Vienna, Austria, when he was four. In 1881 he received his M.D. degree from the University of Vienna. Freud's experiences in the Vienna General Hospital awakened his interest in the study of nervous diseases. In 1884 a case of hysterical paralysis cured by hypnotism started Freud on his own investigations.

Freud worked in Paris with the neurologist Jean M. Charcot in 1885–86, and published papers on loss of memory and on cerebral paralysis in children. In Vienna, Freud and Joseph Breuer treated nervous cases by hypnotism. By 1894 Freud had abandoned hypnotism and had developed the technique of free association and dream analysis. His patients were encouraged to relax on a couch and talk frankly to him about their dreams, childhood memories, and anything else that came to mind.

Freud was appointed a professor of neurology at the University of Vienna in 1902. He held that position for 36 years. In his later years Freud no longer analyzed patients personally, but devoted his time to writing. He was elected to the British Royal Society in 1936. In 1938, when Nazi Germany seized Austria, Freud and his family found safety in England. He became a British subject.

Freud's many writings include The Interpretation of Dreams (1900); The Psychopathology of Everyday Life (1904); A General Introduction to Psychoanalysis (1910); Totem and Taboo (1913); Ego and Id (1923); Moses and Monotheism (1939). Freud's Collected Papers (1959) was edited by Ernest Jones.