Arnobius the Younger

Arnobius the Younger was an African who lived as a monk in Rome around the middle of the fifth century. He is called the Younger only to keep him apart from Arnobius of Sicca, the North African apologist who wrote a century and a half earlier. The two are unrelated.

His largest surviving work is a running commentary on the Psalms, written about 460. It is brief where brevity will do, allegorical in method, and openly polemical: he uses the Psalms to attack the Augustinian doctrine of predestination. He belonged to the party in southern Gaul and Italy that accepted Augustine on grace but balked at his teaching that God's choice precedes and determines a man's response. His commentary was first printed by Erasmus in 1522, which put an obscure fifth-century monk into the hands of the Reformation.

His second work is a dialogue, the Conflictus with Serapion the Egyptian. Arnobius argues against a monophysite opponent about the two natures of Christ, taking the settlement of Chalcedon in 451 as his standard, which dates the book after that council. The dialogue also handles the Trinity and, notably, the question of grace, and here Arnobius defends Augustine against the Pelagians almost as if Augustine were an apostle.

That is the puzzle scholars have never resolved. The same man appears to attack Augustine's predestinarianism in one book and defend Augustine's anti-Pelagian teaching in another. Some have concluded that he wrote at different stages and changed his mind; others that he wrote under cover, saying different things in different genres. A long anonymous work called the Praedestinatus, which caricatures the doctrine of predestination by putting it in the mouth of a heretic, has also been attributed to him, and would deepen the same difficulty.

What he shows is a real and unfinished argument. Augustine died in 430; the church did not simply receive his doctrine of grace whole. For a hundred years afterward, monks and bishops in Gaul, Italy and Africa fought over how much of it to keep, and the Council of Orange in 529 would settle only part of the question. Arnobius is one of the voices in that fight, and his commentary carried the argument into print eleven centuries later.

Sources: Arnobius the Younger, Commentarii in Psalmos and Conflictus cum Serapione (Corpus Christianorum, Series Latina 25 and 25A); Gennadius of Massilia, De viris illustribus; The Catholic Encyclopedia (1913), s.v. "Arnobius the Younger".