Medieval Christians read Muhammad’s sincerity as fraudulent hypocrisy because he opposed their ethics knowingly

Evidence

This probably explains the constant preoccupation with Muhammad’s ‘hypocrisy’. Muhammad became essentially the simulator sanctitatis, although the things he had done were things that Islam, following him, did not believe to be sinful at all. Temptations of the world and the flesh were encouraged by the substitution of a fleshly Paradise for damnation. As Muhammad’s life was understood, it was impossible to suppose that he acted contrary to Christian ethics without knowing what they are. He simply seemed by actions and doctrines alike to oppose Christianity. Enough was known about him for it to be clear that everything he did, he did for religious reasons and with religious motives. The only possible conclusion in those days was that he was a fraud who hid his wicked designs beneath a mask of religion; and the gravity of the matter made it inevitable that this view should always be stressed. — Norman Daniel, Islam and the West, 1491

Categorization

• XREF: Connects to the vault thread on Islam as the West’s constitutive outside — Michael’s sincerity making him all the more a fraud parallels how constructed enemies must be read as knowingly evil (cf. Razack’s Casting Out logic on Muslim culpability).
• CANDY: The idea that Muhammad was judged a hypocrite specifically because he was believed sincere — his very religiosity was the evidence of fraud — is a compact, tweetable paradox.