Volume 79 in the Collected Works of Erasmus series presents two works written by Erasmus in a controversy with the Carthusian monk Pierre Cousturier.

Erasmus had ignited controversy throughout Europe with his criticisms of the Vulgate in current use and his attempts to produce better texts and better Latin translations of Scripture, as well as a new version of the Greek New Testament. Erasmus's work came under the scrutiny of the Paris faculty of theology. The resulting controversy between Erasmus and various Paris theologians culminated in a formal censure of both vernacular translations of the Bible and new Latin translations from Hebrew and Greek sources.

In 1522, Pierre Cousturier began to attack humanist translators in a series of publications, arguing for the accuracy and divine inspiration of the commonly used Latin Bible, which rendered further Latin translations unnecessary, even dangerous. The fact that Cousturier had a doctorate in theology from Paris and was highly regarded in the Paris basin as a reformer prompted Erasmus to reply in order to clarify his textual and theological principles and their implications. In his Apologia against Cousturier and the subsequent Appendix, Erasmus offers some of his most important reflections on his aim to cultivate humanistic and linguistic expertise in the service of advancing the Gospel.