<P> Freud later used his notion of the unconscious in order to explain certain kinds of neurotic behavior . The theory of the unconscious was substantially transformed by later psychiatrists, among them Carl Jung and Jacques Lacan . </P> <P> In his 1932 / 1933 conferences, Freud "proposes to abandon the notion of the unconscious that ambiguous judge". </P> <P> Carl Gustav Jung, a Swiss psychiatrist, developed the concept further . He agreed with Freud that the unconscious is a determinant of personality, but he proposed that the unconscious be divided into two layers: the personal unconscious and the collective unconscious . The personal unconscious is a reservoir of material that was once conscious but has been forgotten or suppressed, much like Freud's notion . The collective unconscious, however, is the deepest level of the psyche, containing the accumulation of inherited psychic structures and archetypal experiences . Archetypes are not memories but images with universal meanings that are apparent in the culture's use of symbols . The collective unconscious is therefore said to be inherited and contain material of an entire species rather than of an individual . Every person shares the collective unconscious with the entire human species, as Jung puts it: (the) "whole spiritual heritage of mankind's evolution, born anew in the brain structure of every individual". </P> <P> In addition to the structure of the unconscious, Jung differed from Freud in that he did not believe that sexuality was at the base of all unconscious thoughts . </P>

What is comprised of material that was once conscious but has been forgotten or repressed