Sigmund Freud (May 6, 1856 - September 23, 1939) was an Austrian neuroscientist who left the laboratory to go into private practice as a neurologist. He founded the clinical and theoretical school of psychoanalysis which holds that human development progresses through a sequence of psychosexual stages which may be interfered with by internalized psychosocial conflicts. To cope with intrapsychic conflict the unconscious mind initiates a defensive process called repression in order to prevent unacceptable sexual and aggressive wishes from becoming conscious, however they remain active in the unconscious and continue to strive for expression. Most commonly, benign evidence of repressed contents can be seen in dreams, jokes, and various Freudian slips. When the mind has to cope with a serious failure of defensive repression, we see the development of symptom constellations called neurosis, which can be treated by bringing the repressed wishes fully and safely into consciousness and releasing the associated pent up emotional accumulation. Freud sought to accomplish this in the privacy and safety of the treatment situation.