Book excerpt: A systematic effort to rethink Freud's theory of the unconscious, aiming to separate out the different forms of unconsciousness. The logico-mathematical treatment of the subject is made easy because every concept used is simple and simply explained from first principles. Each renewed explanation of the facts brings the emergence of new knowledge from old material of truly great importance to the clinician and the theorist alike. A highly original book that ought to be read by everyone interested in psychiatry or in Freudian psychology.