This entry presents the theoretical and philosophical ideas of Swiss psychiatrist Carl Gustav Jung (1875–1961). It demonstrates that the notions of the collective unconscious, archetypes, and individuation lie at the core of his concepts of complexes and psychological types and represent his most significant theoretical contributions. It then assesses the legacy of these ideas and the extent to which they have failed to gain traction within academic settings. It concludes by introducing Jung’s role as a formulator of a version of the philosophical position of dual-aspect monism and suggests that this facet of his work may ultimately result in a reevaluation of his hitherto devalued place within theoretical and philosophical psychology.