Mediaeval Christians knew Islam only as a foil to Christianity

Evidence

In all these matters there was much ignorance, and many mistakes were made. Only a reader who was already well-informed would have been able to pick out the statements that were true. There was not even much interest. There was practically no systematic comparison of the interior life of the two religions. What interest did exist was genuine, but it was very limited. Christendom was relatively indifferent to what did not touch immediate Christian interests. This is not to say that there was no perception at all of the realities of Islamic spiritual practices; but these had little significance except as a contrast or a foil to the ways of Christians. Islam was always a reflection, often a muddied reflection, of what was familiar at home. In the consciousness of mediaeval writers, it was never inherently attractive or by its nature edifying. Even when Muslims were seen to obey the divine law in morals, it was usual to interpret Islam as a falling short of being Christian. — Norman Daniel, Islam and the West, 1280

Categorization

• XREF: Directly parallels Anidjar’s claim that ‘Islam’ functions only as the West’s constitutive outside/negative mirror — medieval Christendom could not see Islam on its own terms.
• QUESTION: How far back does this ‘Islam as reflection of home’ perceptual structure trace, and does it prefigure modern Orientalism’s mirroring in Said?