There is a morbid fascination in any survey of the ascetic practices of humankind. Fasting, the virgin priestess, and the mutilation of the body are common features of ancient religions. In monastic Christianity the austere ideals of celibacy, obedience, and poverty have been both practiced and admired. Even today there are many who observe Lent and those for whom fasting and penance are seldom out of season. The most accomplished ascetics have been the wanderers (sunnyasins) of ancient India and the anchorites of fourth-century Egypt. One sunnyasin held his arms above his head with fists clenched until the muscles in his arms atrophied and the nails grew through his palms. It is said that the anchorite St. Simeon Stylites tied a rope tightly around himself until it ate into his body and his flesh became infested with worms. As the worms fell from his body he replaced them...