reality principle (Realitätsprinzip) The counterbalance to the pleasure principle in Freud, Sigmund’s early account of mental functioning. It regulates and restricts the subject’s search for the immediate satisfaction of their desire, postponing gratification according to the conditions imposed by external reality. The reality principle emerges after the pleasure principle and only takes formation when the psychical apparatus has undergone significant development (i.e. when the rational processes of judgement gain ascendancy in the conscious). The reality principle never attains absolute mastery over the pleasure principle, particularly where the sexual instinct are concerned, so it must constantly reassert itself.