In two volumes, comprising a total of almost a thousand pages, the author presents a series of letters which presumably recite the difficulties in the sexual lives of many of his patients. The form in which this material is made available has been especially chosen by the author because of the opportunity that it gives to include not only the points commonly considered significant in case history, but also the environmental factors that may have a bearing on the disturbances of sex life for which consultation was sought. The letters in most instances are addressed to a colleague who has presumably submitted the case for study, others to a mother or a father who requires advice, and a few to the patient himself. Practically all of the aberrations of sexual life are concerned. The explanations, which are in easily understood German, are based largely on freudian conceptions of sexual relationships.