Raymundus Lullus (Ramon Lull) tells of an educated Mohammedan ruler, who, when urged by a missionary to embrace the Christian faith, answered him: “Prove to me that your faith is true; then I, with all my subjects, shall adhere to it.” The missionary replied that Christian faith is too sublime a thing to be proved, and he contented himself with explaining the actual belief of the Christians. Answered the king: “If you ask me to leave what has been my faith thus far, then you should give me something reasonable instead of it.” Lull uses this story in order to warn missionaries among the Mohammedans not to follow such a method. According to him, it is useless and even ridiculous to refuse to discuss Christianity in philosophical terms in giving demonstrations of its truth to people who are acquainted with such a method.