Abu Hatim Ar Razi

Muhammad ibn Idris ibn al-Mundhir ibn Daud ibn Mahran, or Abu Hatim Ar Razi in short, is a leader, hafiz, naqid (eminent critic), and respected man in hadith science. He criticized and praised narrators, validated and revealed as minor faults as possible in hadith. His critics on hadith narrators were summarized by his son in the book of Al Jarh Wat Ta'dil.

Adh Dhahabi said that when Abu Hatim praised a narrator, then cling to his words, because he never says a narrator is thiqat unless the narrator is really thiqat. And if he weakened someone or said 'That man's words can't be used as arguments', then stop, you should see what other scholars said about that man. If the majority of scholars says the man is thiqat, then ignore Abu Hatim's critics, for he overcriticized (muta'annitun) in assessing the narrators. He criticize several Sahih narrators as "his words can't be used as argument" or "not strong" or likewise.