War, revolution, and psychoanalysis: Freudian thought begins to grapple with social reality.

Psychoanalytic theory and practice have been affected by external events as well as by internal development. Specifically, the period of the Great War and its aftermath was a turning point in the history of psychoanalysis. These experiences emphasized the inadequacy of the libido theory alone, accelerated Freud's impetus toward metapsychology, and encouraged the articulation of theories of innate destructive urges, of ego instincts, of the superego, and of social interaction. Discussions of war neuroses, of aggression and the death instinct, of the reality principle, and of the mechanisms of social psychology undermined Freud's original biologism in favor of a social-scientific approach. Psychoanalytic theory began to take more account of social experience and was profoundly changed in the process.