Carl Jung was a noted Swiss psychiatrist and the founder of Analytical Psychology. One of the most innovative thinkers of his time, Jung approached the unconscious through exploration of dreams, the study of art, mythology, religion, fairy tales, alchemy, and philosophy. Many of today's mainstream psychological concepts originated with Jung. These include the terms extraversion, introversion, personality types (further advanced by Meyers-Briggs), the collective unconscious, archetypes, shadow, anima, animus, persona, and complex.
In his youth, Jung was introverted and paid attention to his inner world of dreams. He originally planned on becoming a philologist (lover of learning and literature) and possibly an archeologist when he went to the University of Basel, but he was conflicted and uncertain. It was during this time that he had a dream that pointed him in the direction of medicine, and eventually psychiatry.
As an attending psychiatrist and researcher at the Burghölzli Mental Hospital in Zurich, Jung noticed that in administering the Word Association Test, associations to words carried different feeling tones for individuals that could be problematic. He called these feeling tones associated with words, “complexes.” Jung also encountered the writings of Sigmund Freud. He became one of Freud's most respected colleagues until the relationship ended over personality and theoretical differences.
Where Freud used free association and the interpretation of the Oedipus complex, Jung focused on the symbolic, archetypal imagery of dreams as well as the spontaneous products of the imagination. Jung envisioned the unconscious as a source of human creativity. His method aimed toward the expansion of consciousness through purposeful cultivation of the relationship between the conscious and unconscious components of the individual personality. This purposeful striving for balance between inner world and outer life is called the “process of individuation.”