Unconscious, a part of the personality that contains the memories, knowledge, beliefs, feelings, urges, drives, and instincts of which the individual is not aware.
Unconscious is the most important concept of dynamic psychology and in particular of psychoanalysis; the region of the psyche that contains impulses and desires which are too threatening to be allowed into consciousness and from which they have been repressed or inhibited from entering. The effects of this repression and inhibition are expressed in consciousness as neurotic behaviour. While Freud did not discover the unconscious (and never claimed to have done so) he systematically probed the dynamic mechanisms involved in its relationship with the conscious psyche and did more than anyone to expose the great amount of irrationality in human affairs.