A thirteenth-century missionary argued Muslims already believe the Trinity

Evidence

Tripoli, writing in the generation before Fidenzio’s, expounded Christian doctrine in terms almost of poetic fire. Muslims, whose conversion in numbers he claimed, wonder at the mystery of the Trinity, unless it be expressed in language which makes it clear to them that it is what they already believe. — Norman Daniel, Islam and the West, 1007

Categorization

• XREF: Shows the medieval Latin West was not monolithically hostile — some polemicists built bridges to Islam, complicating the vault’s constitutive-outside narrative.