Why do mystics and devout laypeople in many different religious traditions glorify physical pain, some going so far as to ritually mutilate themselves in the name of the divine? In this erudite and wide-ranging study, Glucklich, a professor of theology at Georgetown University, offers a compelling explanation. Drawing on the fields of psychology, neurophysiology and religious studies, he observes that pain 'the most familiar and universal aspect of all human experiences' affects both the body and the mind. Pain triggers an altered state of consciousness in which one's sense of self is diminished, creating an absence that can make way for a new and affirming presence. 'The task of sacred pain,' Glucklich writes, 'is to transform destructive or disintegrative suffering into a positive religious-psychological mechanism for reintegration within a more deeply valued level of reality than individual existence.' Although this state of transcendence exists across cultures, the way in which the experience is interpreted is culturally specific. To demonstrate this, Glucklich draws upon a wide range of examples, from the tortures of the Inquisition to Native American trials of endurance. He concludes by exploring what we may have lost with the development of medical anesthetics. This fascinating, closely argued study suggests that, in religion as in sports, there is no gain without pain.