Sigmund Freud first referred to the unconscious and to unconscious motivation in a letter to Josef Breuer. Freud referred to a "second state of consciousness" that participated in a "principle of constancy." He concluded that "the psychical experiences forming the context of hysterical attacks . . . are all of them impressions which have failed to find adequate discharge."

Type of event: Other Notable Event

Country: Austria

Region: Europe and the former USSR