A 12th-century Christian scholar dismissed earlier anti-Islamic polemics as lacking theological taxonomy.

Evidence

While Peter uses the works of earlier anti-Islamic polemicists, he clearly felt they were inadequate. He sets aside much of their material, apparently deeming it useless: for example the names of Muhammad’s associates or the polemical descriptions of ‘Alî’s teachings and the birth of Shi’ism (Peter did not know enough about Islam to appreciate the importance of the latter). On the other hand, Peter finds that these earlier polemics lack a proper taxonomy of error, a sense of Islam’s place in the divine plan. The devil inspired heresiarchs to lead the faithful into error; only through careful comparison with the teachings of other heresiarchs and the perusal of antiheretical works of the church fathers could this new and dangerous heresy be combated. — John V. Tolan, Saracens, 845

Categorization

• DEFINE: Introduces the concept of a ‘taxonomy of error’ — situating Islam in a genealogy of heresies — as a polemical method distinct from mere factual denunciation.