According to Freud's structural theory of the mind, the id, the ego and the superego function in different levels of consciousness. There is a constant movement of memories and impulses from one level to another.

The id is the unconscious reservoir of drives, which are constantly active. Ruled by the pleasure principle, the id demands immediate satisfaction of its urges, regardless of undesirable effects.

The ego operates mainly in conscious and preconscious levels, although it also contains unconscious elements because both the ego and the superego evolved from the id. Ruled by the reality principle, the ego takes care of the id urges as soon as the adequate circumstance is found. Inappropriate desires are not satisfied but repressed.

Only partially conscious, the superego serves as a censor on the ego functions and comprises the individual's ideals derived from the values of his family and society, being the source of guilty feelings and fear of punishment.

Copyright Gizmo, Delusion, Presence, 2001