psychic apparatus
in classical psychoanalytic theory, mental structures and mechanisms. Sigmund Freud initially (1900) divided these into unconscious, preconscious, and conscious areas or systems and later (1923) into the id, ego, and superego: The id is described as unconscious, and the ego and superego as partly conscious, partly preconscious, and partly unconscious. Also called mental apparatus. See also structural model; topographic model.