pleasure principle
the view that human beings are governed by the desire for gratification, or pleasure, and for the discharge of tension that builds up as pain or “unpleasure” when gratification is lacking. In the classical psychoanalytic theory of Sigmund Freud, the pleasure principle is the psychic force that motivates people to seek immediate gratification of instinctual, or libidinal, impulses, such as sex, hunger, thirst, and elimination. It dominates the id and operates most strongly during childhood. Later, in adulthood, it is opposed by the reality principle of the ego. Also called pleasure–pain principle.