"This is a lively and interesting book as well as a valuable addition to contemporary studies in Islamic theology and jurisprudence." — Jane Dammen McAuliffe, Chair, Department for the Study of Religion, University of Toronto"This is a thorough and systematic study of a discrete and important, but little-known issue in the field of Islamic ethics. Using an impressive array of manuscripts and published sources, the author demonstrates that during its formative period, Muslim theological doctrine was fluid, and that scholars who reportedly were members of a particular school often held views that were at variance with school doctrine. In this respect, the author's conclusions are important and significant." — David S. Powers, Cornell University"The topic is of very considerable importance for the intellectual history of medieval Islam. Not only does the author deal with questions that are central to the history of Muslim religious thought, he is the first scholar (so far as I am aware) to treat in a systematic and sustained fashion the particular set of questions addressed in this work. Even those whose primary interest is in the modern period will find the work to be useful in illuminating certain developments in the nineteenth and twentieth centuries." —— Merlin Swartz, Boston University