Medieval polemicists portrayed Islam as a compilation of earlier Christian heresies.

Evidence

His goal is to comprehensively refute the Koran; he makes extensive use of earlier polemical tracts, especially the Liber denudationis, but also Peter the Venerable (and the Corpus toletanus) and Ramon Martí. He follows Peter the Venerable in portraying Islam as the sum of all previous heresies: “the excrement of all the ancient heresies, which the Devil had sparsely sprinkled in each, Muhammad revomited it all together.” — John V. Tolan, Saracens, 1259

Categorization

• XREF: Shows the heresiology-borrowing tradition Anidjar notes: Islam framed as derivative deviance from Christianity rather than a religion in its own right.
• SEED: The scatological revomiting metaphor as a polemical strategy — disgust-language doing classificatory work throughout medieval Christian-Islamic polemic.