An attempt is made to define systematically the unknowns in the therapeutic relationship, particularly the unconscious influences of the therapist's theories, ideology, and interpretations on the patient. The therapeutic relationship is shown to have striking similarities to the methods used by Chinese experts in thought control. The author concludes that we know little of scientific value about the causes of psychotherapeutic and psychoanalytic success and failure, and he outlines several promising lines of research. The psychoanalytic reader will find most valuable Frank's survey of psychoanalytic, experimental psychological, psychiatric, and psychosomatic contributions to the subject.