Medieval Christians grouped Islam and dissident Eastern Churches into one renegade category

Evidence

Sometimes, when the distinction between dissident Christian Churches and Islam was expressly drawn, this served only to suggest its contrary; such passages seem to reveal a natural tendency to think of every society that disowned Roman obedience in a single category. All the separated bodies called for reunion. William of Adam, the Bishop of Sultaniyah, expressly excluded Islam from the same class as the Greeks, whose greater feebleness (though equal malice), when compared with Muslims, derived from their having ‘left the Roman Church’. Humbert also classed the znfidel as outside even the riven unity of the Church; at the Council of Lyons the Western Church needed to reform its morals, the Eastern its faith, in order to unite against the external menace of Islam.*® In these examples, William certainly thought of the different enemies of the Catholic Church together, and even with Humbert, the reunion with the Orthodox looks like the first stage in the reunion of the world. — Norman Daniel, Islam and the West, 1064

Categorization

• XREF: Connects to the reader’s climate/regulatory history and other historical-reputation work where classification of outsiders shapes policy.