The first book of its kind to provide a detailed analysis of the history of the unconscious from the underworlds of Greek and Egyptian mythology to psychoanalysis and metaphysics, Jon Mills presents here a unique study of differing philosophies of the unconscious. Mills examines how three major philosophical systems on the nature of the unconscious emerge after modern philosophy, finding their most celebrated elaborations in Freud, Lacan and Jung. These three psychoanalytic traditions, quite separate from one another in terms of their emphasis and philosophical presuppositions, are scrutinised alongside contemporaneous movements in existential phenomenology, semiotics, epistemology, transcendental psychology and Western metaphysics in the texts of Hegel, Heidegger, Sartre and Whitehead. Underworlds provides a scholarly exegesis and critique of the main philosophies of the unconscious to have transpired in the history of ideas. Exploring the unconscious from its philosophical beginnings