id

n. The basic inherited motivations of the organism. In Freud's psychoanalytic theory, the id is primitive, impulsive, and pleasure seeking and needs guidance by the rational ego and the moral superego in order to function in the world. In later versions of Freudian theory, the id has only two instincts, Eros, or pleasure, and Thanatos, or death and aggressiveness. In other theories, such as Henry Murray's, the id is much more diverse and includes prosocial as well as selfish instincts.