By 1250 the unity-of-God doctrine was common Christian knowledge about Islam

Evidence

At first, however, it is likely that the Latins, who had no experience of religions other than their own, could only imagine error taking the form of extravagance along familiar lines. If Christians worshiped a Trinity, so (they imagined) must Moslems, but an absurd one; if Christians worshiped their Founder, so (they imagined) must Moslems, but with depraved rites suitable to a depraved man and a depraved people. — R. W. Southern, Western Views of Islam in the Middle…, 186 (#complicates, via linked claim)

Even so we can say that there was in the West some knowledge that Islam was a system of positive requirements, and not only a series of relaxations. Praise of Muslim practice, to shame Christians, equally with attempts to describe Islamic morals, made it clear that to some extent Islam and Christianity drew upon a common stock of precepts. — Norman Daniel, Islam and the West, 1128 (#corroborates, via linked claim)

Categorization

• XREF: connects to: Medieval Christians constructed Islam and Judaism as mutual templates — Ivan Davidson Kalmar, Derek Penslar, Orientalism and the Jews, 235; Twelfth-century Christian interest in Islam was driven by its cultural prestige; Medieval Christian writers recognized Islam shared their moral precepts — Norman Daniel, Islam and the West, 1128 (+15 more)

Related

• Medieval Christians understood Islam only as a distorted copy of Christianity (similarity 0.89)
• Medieval Christian writers recognized Islam shared their moral precepts (similarity 0.86)
• Medieval Christians invented a distorted Muslim Trinity as mirror of their own faith (similarity 0.85)
• Medieval Christians valued Qur’anic Christ references over Islamic monotheism (similarity 0.84)
• Medieval Christians constructed Islam and Judaism as mutual templates (similarity 0.84)
• Medieval theologians classified Islam in multiple overlapping religious frameworks (similarity 0.84)
• Medieval Christian writers assumed Muslim doctrine derived from misinterpreted Scripture (similarity 0.84)
• Islam’s selective agreement with Christianity defied medieval categorization (similarity 0.84)
• Medieval Christian accounts of Islam’s origins recycled a few basic narrative permutations (similarity 0.83)
• Trinity disputes dominated Christian thinking about Islam rather than God’s unity (similarity 0.83)
• Medieval Christians interpreted Muslim ritual through Christian sacramental categories (similarity 0.83)
• Some medieval Christians recognized all three faiths worshipped the same one God. (similarity 0.83)
• Medieval Christians valued Qur’anic Christology over its proclamation of divine unity. (similarity 0.83)
• Medieval Christians understood Muslims as revering biblical prophets and Jesus (similarity 0.83)
• Medieval Christians weaponized accurate Islamic learning for polemics (similarity 0.82)

Broader Connections

• Medieval Christians invented a distorted Muslim Trinity as mirror of their own faith #complicates (0.99) — R. W. Southern, Western Views of Islam in the Middle…, 186
• Medieval Christian writers recognized Islam shared their moral precepts #corroborates (0.95) — Norman Daniel, Islam and the West, 1128
• Medieval anti-Islamic polemic circulated as a living shared tradition #corroborates (0.95)
• Medieval theologians classified Islam in multiple overlapping religious frameworks #corroborates (0.92)
• Twelfth-century Christian interest in Islam was driven by its cultural prestige #responds-to (0.90)
• Medieval Christians understood Islam through preexisting biblical categories rather than direct encounter #corroborates (0.90) — John V. Tolan, Saracens, 88
• Medieval Christian accounts of Islam’s origins recycled a few basic narrative permutations #corroborates (0.88) — Norman Daniel, Islam and the West, 481
• Islam’s selective agreement with Christianity defied medieval categorization #corroborates (0.88) — R. W. Southern, Western Views of Islam in the Middle…, 29
• Islamic philosophy shaped even orthodox medieval Christian theology #corroborates (0.85) — R. W. Southern, Western Views of Islam in the Middle…, 328
• Medieval Christian knowledge systems failed to explain or influence Islam #qualifies (0.85) — Edward W. Said, Orientalism, 168
• Medieval Christians understood Muslims as revering biblical prophets and Jesus #corroborates (0.81) — Norman Daniel, Islam and the West, 126
• Medieval Christians constructed Islam and Judaism as mutual templates #expands (0.80) — Ivan Davidson Kalmar, Derek Penslar, Orientalism and the Jews, 235
• Medieval Christians interpreted Muslim ritual through Christian sacramental categories #complicates (0.80)
• Medieval Christian writers assumed Muslim doctrine derived from misinterpreted Scripture #qualifies (0.75) — Norman Daniel, Islam and the West, 315
• Medieval Christians imagined heretic-Muslim-traitor alliances spanning all of Europe #complicates (0.75)