Throughout his career, Richard Simon passed critical but nuanced judgments on Saint Augustine’s work: his “novelty” in comparison to the Greek Fathers, his ignorance of the Biblical languages, Hebrew and Greek, and his creation of a system (“effi cient” grace) that broke with tradition. Bossuet vehemently protested against these criticisms; the opposition between the two authors reveals the opposition between two conceptions of tradition and two doctrines of grace.