The book studies the practice of apostasy and its punishment in Islamic jurisprudence. It provides ample historical background as the author explores the concept, practice, and punishment accompanying these in Judaism, Christianity, Greco-Roman, and other historical circumstances. The author examines these concepts and practices in the Quran, the Sunnah, and different denominations. It tries to understand the reasons for the severity of the sentence and questions its adequacy within the scope of compulsion in religion. It scrutinizes the political conjuncture in which the punishment was created by the scholars, the reason for the punishment and the legal benefits expected from it, the nature of the punishment, and its place in the punishment system, from ancient history all the way to contemporary law.