This remarkably clear and lucid presentation is part of a symposium on Aggression in Relation to Emotional Development—Normal and Pathological, delivered at the International Congress of Mental Health in London, August 1948.

The first section briefly outlines the historical development of the instinctual theories in psychoanalysis. For thirty years the psychoanalytic study of instinctual life was directed almost exclusively toward the manifestations of sexuality. Aggressive behavior observed in children was first understood to be a component of pregenital sexuality. Later it was believed that frustration of instinctual wishes was the starting point of aggression. Freud's last formulations conceived of aggression as a manifestation of a basic instinct equal in status to the sexual instincts which led to his theory of the life and death