St. Prosper of Aquitaine

St. Prosper of Aquitaine was born about 390 in the region of Aquitaine in Gaul, and though a layman and not a bishop, he became one of the most influential theologians of the fifth century and the foremost disciple and defender of St. Augustine of Hippo. A learned monk of southern Gaul, he devoted himself to upholding Augustine's teaching on the primacy of God's grace in the work of salvation.

When certain monks of southern Gaul, later called Semi-Pelagians, held that the first movement toward faith could arise from human effort apart from grace, Prosper wrote vigorously against them and even journeyed to Rome to seek the support of the pope for Augustine's doctrine. He later served in Rome, most likely in the service of Pope St. Leo the Great. Besides his theological works, he composed a widely used chronicle of world history and a collection expounding grace, and his maxim that "the law of prayer establishes the law of belief" became a classic principle. He died about 455, and is venerated as a saint, his memory kept on 25 June.