Career
His work is the only life of Ambrose based on a contemporary account, and was written at the request of Augustine of Hippo. lieutenant is dated to 422.
In Carthage in 411 he had opposed Caelestius, a Pelagian. The formal proceedings were described by Augustine in On Original Sin.
Paulinus set up six theses defining Pelagian views as heresy.
Caelestius gave up on becoming a presbyter in Carthage, moving to Ephesus
Paulinus was summoned to Rome in 417, to justify himself. With local backing, he declined to appear before Pope Zosimus.
In 418 the Pope took into account the measure of support for the anti-Pelagian position, and condemned both Caelestus and Pelagius.