Why does society become demoralized in the process of revolution? Why should a change in the political procedures of the community unleash such excesses in behavior? Reflection might lead one to suppose that since important decisions are in process of being made, calm deliberation would characterize society. Evidently a reactivating process is at work here; there is a regressive tendency to reawaken primitive sadism and lust. The conspicuous disproportionality between the problem and the behavior necessitates an explanation in such terms. Federn published a sketch of the psychology of revolution in his pamphlet _Die vaterlose Gesellschaft_ in 1919. When the ruler falls, the unconscious triumphantly interprets this as a release from all constraint, and the individuals in the community who possess the least solidified personality structures are compulsively driven to acts of theft and violence. An interview which Federn gave to Edgar Ansel Mowrer in 1927 on the occasion of the Vienna riots reviews in somewhat popular form some of his conceptions. Vienna, Austria, July 20.--“Distrust of father was the chief cause of the Vienna riot,” said Paul Federn, onetime president of the Psychoanalytical Society. From a psychoanalytical standpoint all authority is the father, and this formerly for Austria was incorporated in the imposing figure of Emperor Franz Josef. But during the war the father deceived and maltreated his children, and only the material preoccupations of life and the joyous outburst when at the close of the war the old authority broke asunder prevented Austria from having a revolution then. The state again built up the old ruling caste and began to hope for restoration, and therefore an abyss opened between Vienna, which under socialist leadership is trying to replace the traditional father principle by a new brotherhood, and the Austrian federal state, which had returned to a modified father idea. Trust in father is the child’s deepest instinct. Vienna first respected the Austrian republic, but gradually this belief was undermined by the continual misery, by newspapers preaching fanaticism and by legal decisions which virtually destroyed the people’s belief in the new father’s justice. Accordingly there occurred a spontaneous manifestation which unconsciously drove the disillusioned and furious children to destroy precisely those things on which the paternal authority seems to rest--namely, records and legal documents.