An enormous advance in the study of Islam is the study of the Dutch scholar and Privy Councillor of the Netherlands, Christiaan Snouk Hurgronje, distinguished by a profound acquaintance with the Arabic sources, a sense of historicity, penetrating criticism, and a persistent logical line of argument. He was a sometime student of Theodor Noldeke at the Reichsuniversitat Straaburg. In his Leiden doctoral study in the Mecca pilgrimage, he convincingly...