Carl Gustav Jung (July 26, 1875-June 6, 1961) was a Swiss psychiatrist and psychoanalyst who founded analytical psychology. Jung's work was influential in the fields of psychiatry, anthropology, archaeology, literature, philosophy, and religious studies. Working as a research scientist, Jung came to the attention of Sigmund Freud, and the two men conducted a lengthy correspondence for a while.
However, while Jung worked on his Psychology of the Unconscious, tensions manifested between him and Freud because of various disagreements, including those concerning the nature of libido. While Jung did think libido was an important source for personal growth, unlike Freud, he did not believe that libido alone was responsible for the formation of the core personality.