Theories of Illness establishes a new landmark in comparative studies. Utilizing concepts from modern medicine and anthropological theory, Professor Murdock distinguishes the natural causes of illness from theories of supernatural causation. He subdivides the latter into theories of illness that are related to aggression (witchcraft, sorcery, and spirit aggression) and those which are related to guilt and a sense of sin (taboo violation and mystical retribution). Obviously, these relate to man's most basic beliefs as revealed in early religions.