The task confronting the person who seeks to survey the current state of the literature dealing with Islam as a religion is both enormous and complex. Since Muslims have traditionally considered themselves to be a religious commonwealth whose very identity is fixed by a shared religious commitment, it follows that virtually every writing on any subject whatsoever having to do with Muslims might be considered to fall within the field of religion. Even if one restricts his attention, as we propose to do here, to a more narrow view of religion, the task is still formidable. Muslims have been no less prolific than other major religious communities in producing dissident opinions from within their own fold. The history of Islamic sects, each with its own peculiar thought system and religious practice, is a field of study in itself and one that might well challenge the most energetic scholar. Far from being monolithic, as many of the scholarly cliches about Islam presuppose (e.g. Islam is a religion of Law, Islam is a religion of the Book, etc.), the religious experience of Muslims is diverse and multiform, defying the most sophisticated attempts to reduce it to order and system. No informed approach to the religiousness of Muslims can deal solely with a narrowly marked out “normative Islam”. The deviations from the norm are also part of the reality of historic Islamic experience and cannot be set aside in favor of what one may prefer as religiously or conceptually pure. It quickly becomes clear to the perceptive inquirer that the meaning of Islam is an historical phenomenon cannot be stated in terms of a unified doctrinal system, a universally accepted set of rites, or common institutions.