Psychoanalytic discoveries regarding man's aggressivity, the viability of the pacifist belief that aggression can be controlled simply by an effort of will, and the role of the superego in coping with man's aggressive and hostile urges are all detailed in this paper. An attempt is then made to show how the law—both by blocking and helping to express man's anger and hostility—gives the superego much-needed help in this task. The conclusion is advanced that the law offers to pacifists and the doctrines they espouse their greatest chance of survival in today's strife-torn world.