Medieval writers read Islam as the Devil’s renewal of older Christian heresies.

Evidence

The Devil’s part in plotting Islam as the renewal of the heresies was thought important by several writers. The Risalah had early proposed a threefold distinction of dispensations; in Peter of Toledo’s wording, that of grace, which was divine; that of justice, which was human, that is, the Mosaic Law; the third revelation could only be diabolical. These schemes of the Devil’s seemed to many mediaeval thinkers to lie behind all the setbacks to the Catholic religion throughout the centuries. … Gerald of Wales took Muhammad after Arius, and saw in the supposed lasciviousness of Islam the calculated cunning of the Devil’s scheme for a hot climate, in contrast to the avarice of the Patari, heretics of a frigid zone, whom he considered next. — Norman Daniel, Islam and the West, 1024

Categorization

• XREF: Connects to the standing claim in the reader’s noise/soundscape work about how cultures demonize the unfamiliar through conceptual schemas. — connects to: Americans recurrently embrace religiously framed conspiracy panics about children and the Devil — Anna Merlan, Republic of Lies, 236
• CANDY: Gerald of Wales mapping heresies to climate zones — lascivious heresies for hot climates, avarice for frigid ones — is a memorably absurd medieval ‘physics of sin.’