Failed missions were blamed on infidels’ irrationality

Evidence

The widespread failure of the missionary movements had become clear by the early fourteenth century, as the fall of Acre and the conversion of the Mongols to Islam made manifest. If the infidels were impervious to the subtle reasoning and clear arguments of the missionaries, the fault must lie with the infidels themselves: the obstinate Jews, lascivious Saracens, and barbarous Mongols, all too obsessed with the literal and carnal to understand the intellectual or the spiritual. — John V. Tolan, Saracens, 1362

Categorization

• XREF: Direct genealogical ancestor of the modern trope that Muslims are impervious to reason and therefore need force — sharpens existing vault claims about Islamophobia’s origins.
• corroborated: 2 independent passages support this claim — John V. Tolan, Saracens, 1362