The economic explanation of history leaves a gap which psychology has to fill. An explosive part is played in historical events by unconscious defense mechanisms against bisexuality, father or mother fixation, sadism, masochism, exhibitionism, and other instincts. The content of radicalism may suddenly swing to the opposite extreme: leftists might change to radical conservatives and vice versa, because of a blind inner urge. Revolutions, the origin of religions, cannot be explained by economic (materialistic) reasoning alone. Not only the "how" of historical developments is created by exceptional men but also the "what."