|Title of host publication||Encyclopedia of medieval philosophy|
|Subtitle of host publication||philosophy between 500 and 1500|
|Place of Publication||New York|
|Publisher||Springer, Springer Nature|
|Number of pages||5|
|Publication status||Published - 2011|
Medieval theologians took their concept of heresy mainly from the texts of Jerome and Augustine quoted in Gratian’s Decretum. Thomas Aquinas argued that anyone who pertinaciously denies even a minor item of church or Bible teaching falls into heresy. Ockham developed criteria for pertinacity and argued that a Christian, even if his or her opinions are actually in error, cannot be regarded as pertinacious simply for refusing to defer to the teaching of a pope.