An intriguing comparative work on religious terrorists -- Christian, Islamic, Jewish, Sikh, and Buddhist -- with an unusual virtue: it takes religion seriously. The author contends that Clausewitz's famous maxim about violence requiring a political purpose may not apply in this case. Indeed, religious terrorists can act on a variety of apolitical motives. Some terrorists are largely theatrical in nature, whereas others believe in cosmic conflicts made manifest on earth; some perpetrators may even believe that their acts carry quasi-magical implications. As a piece of practical sociology, unfortunately, the book does not quite convince with its possible solutions to religious terrorism, whose agents are more potentially lethal today than ever before despite their small numbers. For example, it is unlikely that a "ritualized cosmic war" will ever replace a true believer's desire for the real thing. Nevertheless, the author's diagnosis deserves attention from those interested in an increasingly common form of violence.