Medieval Christian polemicists demanded Muslims accept the whole Christian canon

Evidence

The Christians - St Thomas Aquinas is the great but lonely exception — wanted to insist that they must. This was most explicit in the Cluniac approach. It was Peter of Poitiers’ view that the Scriptures must be accepted or rejected whole, and his Abbot elaborated this. For him it was quite intolerable that the Muslims should make use of the names of characters in Sacred Scripture without accepting the whole canon. They should entirely reject Scriptures — ex toto reprobandae sunt — if they could not accept them, as they ought, in their entirety. It was their duty to accept the Jewish Prophets, because the Holy Ghost inspired them, whatever their racial origin; and also because Arabs and Jews shared the same inheritance: the descent from Ismael and Isaac; the practice of circumcision inherited from their father Abraham ‘either by innate usages or by laws that have been handed down’; common race, an ‘almost common’ language, style and ‘famous things of literature’. Within the circumambience of his second-hand knowledge, Peter would often return to his fundamental point. He exhorted Muslims, ‘either abandon the Qur’an, because of the false things which have been taken out of Books which you call false, and put into your Book; or, if you do not want to do that, acknowledge that the Christian and Hebrew Books from which these things are taken are true’. … Peter the Venerable’s humane and enthusiastic personality, his limited power of discrimination, are reflected in this insistence on premises unacceptable to his opponents. — Norman Daniel, Islam and the West, 314

Categorization

• XREF: Connects to the irony that Peter the Venerable, who commissioned the first Latin Qur’an translation out of genuine engagement, held arguments premised on premises Muslims could never accept — mirrors how interfaith dialogue assumes shared frameworks.
• QUESTION: Peter of Poitiers vs Peter the Venerable — the author conflates or distinguishes them carefully; worth checking which Peter authored which view.