This volume includes a depiction of the attempt of the introvert to adjust himself to his environment. It is based on personal experience and is largely biographic. The author is firmly convinced of the soundness of the classification of all mankind into introverts and extroverts. He believes that in practically all instances marriages occur between opposites, from this point of view. Indeed, he believes that the balance of civilization is apparently maintained by association of such opposites in many ways. The introvert type, he believes, is far more common than the extrovert, and he includes professional workers particularly in the introvert group. He even has a conception as to the nature of the healing of disease. The volume is interesting as a psychologic document.