Christian authors framed Islam using pre-existing biblical categories, not firsthand knowledge

Evidence

This is why I begin this survey of Christian perceptions of Islam before the rise of Islam. The point is to show how key Latin Christian authors of the seventh century viewed their world: in particular, how they defined the differences between Christian and non-Christians (Jews, pagans, and heretics) and what they saw as their place in history. For when they first meet Muslims they will try to understand their military successes and their religion in terms familiar to them, to fit Islam into already existing Christian categories by portraying them, variously, as a divinely sent punishment, as pagan idolaters, as Christian heretics, as followers of Satan, or as devotees of Antichrist. — John V. Tolan, Saracens, 88

Categorization

• XREF: Directly supplies the historical root-cause mechanism underlying Anidjar/Aziz/Razack claims about persistent Islam-West oppositional framing.
• ADDENDUM: Grounds the genealogical method of the existing vault claims by locating where ‘Saracen-as-enemy’ categories get their epistemic template.
• SHARE: The 5-fold typology (punishment, idolaters, heretics, Satanists, Antichrist devotees) compresses the whole medieval taxonomy into one list worth passing to anyone mapping anti-Islam rhetoric.