In this innovative study, Kecia Ali examines the forefather of the second largest of the four principal Sunni schools of jurisprudence, the Shafi'i. Gifted poet and outstanding Islamic Scholar, Abu Abdullah Muhammad ibn Idris al-Shafi'i (767-820) firmly rejected the use of common sense in Islamic legal rulings, arguing that the only valid sunnah (or prophetic religious traditions) were directly handed down from Muhammad by Hadith. Kecia Ali is Assistant Professor of Religion at Boston University. She is a world authority on Islamic jurisprudence, and author of Sexual Ethics and Islam: Feminist Reflections on Qur'an, Hadith and Jurisprudence.