Ahmad ibn Hanbal (d. 241 H/855 AD), renowned for his profound knowledge of hadith--the reports of the Prophet's sayings and deeds--is a major figure in the history of Islam. Ibn Hanbal was famous for living according to his own strict interpretation of the Prophetic model and for denying himself even the most basic comforts in a city then one of the wealthiest in the word, and despite belonging to a prominent family. His piety and austerity made him a folk hero, especially after his principled resistance to the attempts of two Abbasid caliphs to force him to accept rationalist doctrine. His...