Medieval Christians classified Muslims as sharing monotheism with Christians but trinitarian denial with Jews

Evidence

Thus Alan of Lille could say that the Muslims agree with the Christians in affirming one God, Creator of all things together; and with the Jews in denying the Trinity within the divine unity. Again, Vitry said that Muslims, like Jews, reject pork and scaleless fish as food, ‘but agree with the Christians in this, that they believe in one only, almighty God, Creator of all things’. — Norman Daniel, Islam and the West, 251

Categorization

• XREF: Corroborates the vault’s constructionist thread: Islam positioned between Christian same-ness and Jewish otherness, mirroring Anidjar’s Jew-Arab genealogy where Islam is triangulated relative to Christianity and Judaism rather than taken as a self-standing category.