According to the eminent French scholar Maxime Rodinson, “Western Christendom perceived the Muslim world as a menace long before it began to be seen as a real problem.” This view is echoed by the late British historian Albert Hourani, who argued that Islam from the time it appeared was a problem for Christian Europe. Looking at Islam with a mixture of fear and bewilderment, Christians could not accept Muhammad as a genuine prophet or the authenticity of the revelation given to him. The most widely held belief among Christians, noted Hourani, was that “Islam is a false religion, Allah is not God, Muhammad was not a prophet; Islam was invented by men whose motives and character were to be deplored, and propagated by the sword.” As the thirteenth-century Crusader and polemicist Oliver of Paderborn claimed: “Islam began by the sword, was maintained by the sword, and by the sword would be ended.”

Centuries of interaction have left a bitter legacy between the world of Islam and the Christian West, deriving largely from the fact that both civilizations claim a universal message and mission and share much of the same Judeo-Christian and Greco-Roman heritage. Separated by conflict and held together by common spiritual and material ties, Christians and Muslims presented a religious, intellectual, and military challenge to each other. The nineteenth century German thinker Friedrich Schleiermacher argued that Christians and Muslims were “still contending for the mastery of the human race.” However, this portrait of unremitting Western-Muslim hostility is misleading.