Medieval Christian polemics could only read Islam as affirming or negating Christianity

Evidence

Muslims, and it did not seek for reasons that might minimise differences and enlarge understanding. Islamic morals were seen, either as denying, or else as reinforcing Christian morals, but never in themselves or distinct from Christianity. — Norman Daniel, Islam and the West, 1457

Categorization

• XREF: This parallels the vault’s existing claim cluster that ‘Islam’ is constituted only as a mirror/other of the West — same binary logic Aziz’s Racial Muslim and Anidjar analyze, here in medieval theological form.