In the work of Guillaume Postel—as diverse as it is disconcerting, the output of a tireless scholar and visionary thinker whom historians of religion, language, travel, and even gender have used to take the measure of Renaissance audacity—the Book of the Concord between the Qur’an and the Evangelicals stands out as one of the most curious pieces.

The parallels Postel draws between Islam and Protestantism in twenty-eight axioms , intended to warn Christians of the calamities threatening them, forms a valuable document on confessional controversy around the mid-sixteenth century. It tells us what was known of the Muslim religion at a time when French humanism was in its prime. It strikes us with a certain quality of indignation. It moves us by the very clumsiness of its opportunism.