Whether Islam technically counted as heresy was debated among medieval Latin theologians

Evidence

Yet in spite of this widespread image of Islam as the culmination or summit of all heresy, it was not at all certain that technically it was a heresy at all. The clearest assertion that it was so was Oliver’s; because of their Christological beliefs, he said, Muslims ought to be called heretics instead of Saracens, but ‘the use of the wrong name has prevailed’. This flat statement is unique, but Peter the Venerable discussed the question fully. It was in the context of the catalogue of the heresies of the past that he came to the problem. ‘I cannot clearly decide’, he admitted, ‘whether the Muhammadan error should be said to be a heresy, and whether its sectaries should be called heretics or heathens.’ There were reasons to prefer the name of heretic. It might be correct to define as heretical nothing but what left the Church and acted against it, but ancient usage called any attack on some part of faith, even outside the Church, heresy, and Muslims, in the usual way of heretics, took what they liked from the sum of Christian doctrine, and rejected as much as they disliked. — Norman Daniel, Islam and the West, 1036 (#corroborates, via linked claim)

Alan’s thought may be clarified by his final prayer that the heretics should leave their deformed dogmas and opinions, the Jews their carnal observances, the ‘pagans’ their superstitious opinions; this seems to place Islam mid-way, with the faults of each, both superstitious and erroneous. — Norman Daniel, Islam and the West, 2283 (#expands, via linked claim)

Categorization

• XREF: connects to: Medieval churchmen genuinely debated whether Islam was heresy — Norman Daniel, Islam and the West, 1036; Medieval theologians placed Islam midway between heresy and paganism — Norman Daniel, Islam and the West, 2283; Twelfth-century Latin writers reframed Islam from paganism to a heresy — John V. Tolan, Saracens, 70 (+7 more)

Related

• Medieval polemicists called Islam a heresy despite its unbaptised status. (similarity 0.93)
• Medieval churchmen genuinely debated whether Islam was heresy (similarity 0.92)
• Medieval theologians classified Islam in multiple overlapping religious frameworks (similarity 0.92)
• Medieval theologians placed Islam midway between heresy and paganism (similarity 0.90)
• Medieval Christians classified Islam ambiguously as both heresy and paganism. (similarity 0.87)
• Medieval authors mislabelled Islamic Christian and Jewish influences as heretical sects (similarity 0.87)
• Medieval Christians first classified Islam as heresy within their own taxonomy (similarity 0.86)
• Medieval Christian polemicists calibrated Islam’s threat by classifying it as pagan or heresy. (similarity 0.86)
• Medieval Christians understood Islam as heresy and lumped Muslims with Jews and heretics. (similarity 0.86)
• Medieval polemicists placed Islam midway between Jewish and pagan error (similarity 0.85)
• Medieval Christians framed Islam as an old heresy rather than a new religion (similarity 0.85)
• Latin Christian polemicists classified Islam as a heresy rather than a separate religion (similarity 0.84)
• Twelfth-century Latin writers reframed Islam from paganism to a heresy (similarity 0.84)
• Orthodox Islam and Christianity each deemed the other’s core doctrine heretical (similarity 0.83)
• Medieval thought cast Islam variously as heresy, schism, and third revealed law (similarity 0.83)

Broader Connections

• Medieval churchmen genuinely debated whether Islam was heresy #corroborates (0.95) — Norman Daniel, Islam and the West, 1036
• Medieval theologians placed Islam midway between heresy and paganism #expands (0.80) — Norman Daniel, Islam and the West, 2283
• Latin Christian polemicists classified Islam as a heresy rather than a separate religion #expands (0.80)
• Twelfth-century Latin writers reframed Islam from paganism to a heresy #exemplifies (0.75) — John V. Tolan, Saracens, 70
• Medieval Christians first classified Islam as heresy within their own taxonomy #expands (0.75) — John V. Tolan, Saracens, 738
• Medieval theologians classified Islam in multiple overlapping religious frameworks #expands (0.75)
• Medieval thought cast Islam variously as heresy, schism, and third revealed law #expands (0.75)
• Medieval Christians framed Islam as an old heresy rather than a new religion #expands (0.70) — Robert Irwin, For Lust of Knowing, 48
• Medieval Christian critics judged Islam by Christian institutional standards #expands (0.70)
• Medieval Christian polemicists framed Islam as lust-driven heresy rather than separate religion #expands (0.70)