Some scholars (Daniel W. Brown, A. Kevin Reinhart) shed doubt on this. Brown believes the theory "fails" to adequately account "for the atmosphere of conflict" of at least early hadith criticism. The "method of choice" of partisans seeking to discredit opposing schools of Islamic law was to discredit the authorities (transmitters) of their opponent's hadith—to "tear apart" their isnads". (To do this required developing biographical evaluations of hadith transmitters -- "ʿilm al-rijāl" and "ilm jarh wa ta’dil"). Reinhart finds descriptions of famous companions of Muhammad in Ibn Sa'd's "Kitāb aṭ-ṭabaqāt al-kabīr" "recording hadith and transmitting it, asking each other about precedents, and reproaching those who disregarded this authentic religious knowledge" in suspicious conformity to the "mythology of the pristine early community".