Authorized translation of Das Buch vom Es by V.M.E. Collins, M.A. Published in 1923 by the Psychoanalysticher; Verlag, Vienna. Georg Groddeck's "The Book Of The It" is a key text in the history of psychoanalytical thought and the investigation of human sexual compulsion. Configured as a series of confessional letters, the book posits the "It" as the unconscious force which drives human behaviour and underpins its poles of attraction and revulsion, and which stands as the root source of physical disease. It was this notion which Freud would modify into his concept of the Id, a primal calculus of sex and violence. Groddeck was an early advocate of self-healing, believing that recognizing the "It" was the first step necessary to understanding human illness. He defines a zone of blood, bodily excretion, mutilation, nightmare and psychosexual dysfunction depicted in atavistic symbolism, culminating in the complex of the Bad Seven, a nexus of orifices presided over by the figure of the castrating wolf. "The Book Of The It" is a text with extreme modern relevance for both students of psychology and those seeking insight into the human capacity for self-repair. With an illuminating introduction by the essayist and novelist Lawrence Durrell.