Demonstrating the central role of third/ninth century" hadith" scholars in the articulation of Sunni Islam, this book bases its findings largely upon the analysis of multiple biographical dictionaries, such as al-Dhahabi's "Tadhkirat al-huffaz," Ibn Sa'd's "Kitab al-tabaqat al-kabir," and collections of the critical comments of Ibn Ma'in and Ibn Hanbal. Part I establishes conceptual and historical frameworks for the study of Sunni "Hadith" scholarship. Part II examines in detail the three foundational principles of Sunni Islam: 1) the collective probity of the "Sahaba," 2) the discipline of "hadith"-transmitter criticism, and 3) a historical vision of the authoritative channels by which "hadith" traversed the two centuries between the life of the Prophet Muhammad and the first major "hadith" books.