Monk and writer. Born to a noble family of Gaul (modern France), he was probably the brother of St. Lupus of Troyes. Vincent initially served as a soldier but gave it up to become a monk on the island of Lerins off the southern French coast near Cannes. He was ordained there and in about 434 authored his famous work the Commonitorium. Written under the pseudonym Peregrinus the Commonitorium offered a guide to orthodox teaching and included his famous maxim, the Vincentian Canon, by which he hoped to be able to differentiate between true and false tradition: quod ubique, quod semper, quod ab omnibus credituni est ("what has been believed everywhere, always, and by all"). He believed that the ultimate source of Christian truth was Holy Scripture and that the authority of the Church was to be invoked to guarantee the correct interpretation of Scripture. A proponent of Semi-Pelagianism, he op-posed the Augustinian model of Grace and was probably the recipient of Prosper of Aquitaine's Responsiones ad Capitula Objectionum Vincentianarum.