The purpose of this work is to present a balanced group of significant professional contributions by outstanding authorities in the field of medical psychology. This modern scientific approach to the study of health and disease, drawing upon psychiatry, clinical psychology, psychosomatic medicine, and other professional disciplines, has enlisted the efforts of scores of physicians, psychologists, anthropologists, and other students of human behavior. The editor's task has been to select and arrange the most pertinent, representative, and comprehensible statements from the current writing and published work of these authorities.