Carl Gustav Jung is the Swiss psychiatrist whose importance in the history of psychoanalysis rivals that of Sigmund Freud. Early in his career Jung worked at the Burghözli mental clinic in Zurich (1900-09), and later he held professorships at universities in Zurich (1933-41) and Basel (1944-61). His early working relationship with the veteran Freud, begun around 1906, deteriorated as Jung became increasingly critical of Freud's insistence on the psychosexual origins of neuroses. After Jung published The Psychology of the Unconscious in 1912, their theories diverged and Jung developed his own school of "analytical psychology." His world travels led to an interest in ideas from Eastern philosophies and religions, which he integrated into his theories of the "collective unconscious." His most famous books include Psychology and Religion (1937), The Undiscovered Self (1957) and his autobiography, Memories, Dreams, Reflections (1962).

Extra credit: The name is pronounced yoong... His work introduced the concepts of "introvert" and "extrovert."