"Hadith" are the documents recording the words and actions of the Prophet Muhammad. Originally an enormous and amorphous corpus, Muslim scholars of the third/ninth century separated the "hadith" they regarded as true from those they held to be forgeries, producing collection of "hadith" which still command the respect of Muslims today. Ibn Abi hatim al-Razi (240/854-327/938) was one of the most prominent exponents and practitioners of "hadith" criticism. He left a copious written legacy, including his famous "Taqdima", a biographical dictionary of the early "hadith" critics. The "Taqdima" reveals Ibn Abi Hatims's vision of the critic and gives insight into the mechanism of "hadith" criticism. It also provides a platform for the examination of the basic intellectual orientation of the "hadith" critics and their conflicts with their opponents.