Of Erasmus’s many scholarly controversies, his exchange with Martin Luther about the freedom of the will is perhaps the best known. The outlines of this controversy can be quickly drawn. Erasmus and Luther had never seen eye to eye, but coldness turned to conflict in September 1524, when Erasmus’s defence of the freedom of the will — the De libero arbitrio — was printed in Basel. Luther mockingly thanked Erasmus for an opportunity to express his views on this topic, responding with his De servo arbitrio (On the Bondage of the Will) in December 1525. The cycle of tract and counter-tract turned again with Erasmus’s two responses to Luther, the Hyperaspistes I of February 1526 and Hyperaspistes II printed a year later