Twelfth-century Christians subsumed Islam under generic diabolical heresy rather than treating it distinctly.

Evidence

These twelfth-century authors, like their predecessors, do not see Islam as an independent phenomenon, a distinct religion. Rather, they see the law of the Saracens as part of a panoply of diabolically inspired error that threatens the souls of Christians and the hierarchy of the church. Faced with this perceived threat (from Saracens, Waldensians, Cathars, Jews, or others), many twelfth-century authors responded with hateful slander, not refuting their adversaries but vilifying them, denigrating them so that their readers could not take them seriously. There were other twelfth-century Christians, however, who attempted a more serious rebuttal of Islamic doctrine. — John V. Tolan, Saracens, 794

Categorization

• XREF: Directly substantiates the existing vault claim that Islamophobia operates on borrowed, non-empirical templates; Islam lumped with Cathars and Waldensians is the medieval root of later conflation logics.
• DEEPTHINKING: The medieval refusal to see Islam as sui generis — and the rhetorical strategy of vilification rather than refutation — is the deep structural ancestor of the modern opposition mapped in the vault.