Though Klein's initial scenario purporting to show how storytellers became priests and shamans is simplistic at best, the next chapter with its several alternative explanations for apparent demonic possession--epilepsy, mass hysteria, Tourette's syndrome, ergot poisoning--should make believers stop and think. Sections on vampires, werewolves, witches, and astrology have less thrust, with their same-old summaries of vampire beliefs and customs, Dracula stories and films, witchcraft persecution, and the casting of horoscopes--but in each case Klein does get around to his mission of debunking. Vampire victims might have been suffering from anemia (perhaps in the form of favism, common in Southern Europe); werewolves might have had the real disease congenital porphyria, or another called hypertrichosis which is characterized by excessive amounts of hair on the face and body; astrology is based on discredited ancient astronomy; and so on. Though Exorcist fever is waning, similar nonsense persists, and Klein brings his argument up to date by exposing the pseudoscientific applications of the biological clock concept. His own approach is far from rigorously scientific and no match for Gallant's Astrology, Sense or Nonsense (1974), but no doubt those who need the message will be more easily reached at Klein's level. It's worth a try.