On July 3, 529, Caesarius of Arles presided over a synod in southern France that was intended to promote the teachings of his favorite theologian, Augustine of Hippo (354-430). Caesarius thought that his fellow church leaders in France had slipped from rigorous Augustinian orthodoxy toward the ideas of Augustine's most bitter enemy, Pelagius. The Synod of Orange was supposed to right the ship and dash Pelagianism once and for all. It didn't.

Augustine was notoriously pessimistic about the human capacity for good. He believed that original sin irreparably tainted all people, so that the only good they could ever do was the good God chose to do through them. He also believed that humans lack the sense or strength to turn to God. Thus it's entirely up to God to save whomever he elects (the doctrine of predestination).

Pelagius didn't like where this thinking led. He particularly objected to Augustine's prayer, "Command what you will, and give what you command." If good will and good action come only from God, Pelagius wondered, are people literally good for nothing? And won't people who are taught that they can't do anything right anyway respond with bad behavior? To preserve morality, and to give humanity some purpose, Pelagius taught that salvation and the Christian life require good use of human free will. He also denied both original sin and predestination.

After 25 years of verbal warfare, Augustine succeeded in getting Pelagianism condemned at the 431 Council of Ephesus. Pelagius, who had never been as "Pelagian" as his followers, had already retreated to a nomad's life in the East. The theology, though, lingered on as "Semi-Pelagianism." As David Allen wrote for CH issue 67: Augustine:

"In Provence, an area of southern France, a group of monks who had all spent time in the important monastery on the Isle of Lé;rins (opposite the modern resort of Cannes) set about correcting what they saw as the extremism of both Pelagius and Augustine.

"John Cassian (360-433), while visiting Egypt to learn spiritual secrets from its famed monks and hermits, heard this from a wizened monk named Chaeremon: 'The grace of God always cooperates with our will for its advantage … and sometimes requires and looks for some effort of good will from it that it may not appear to confer its gifts on the sluggish.'

"This is the earliest expression of what came to be known as Semi-Pelagianism—a view that Cassian embraced and later began to propagate. The key word is cooperation: no one can save himself but, by cooperating with the grace of God, salvation can be appropriated by anyone."

Other men, notably Vincent of Lé;rins and Faustus of Riez, took up Cassian's theme. Both of these men were dead by the time Caesarius and other Augustinians fought back at Orange, but Semi-Pelagianism had spread further than Caesarius realized—into the Augustinian camp. Allen notes, "even the synod backed away from some of Augustine's more extreme views: his belief that God's grace cannot be resisted and his severe interpretation of predestination were quietly dropped."

Eventually, more Augustinian objections to Pelagius were quietly dropped. A millennium after Orange, Martin Luther & co. would accuse the entire Roman Catholic Church of going soft on sin and diluting predestination with emphasis on good works. It seemed to Luther that while Augustine had won every specific battle with Pelagius, he had lost the war for orthodoxy. Depending on your view of Pelagianism, it shows that you just can't keep a bad—or good—idea down.

CH issue 67 is available online here: http://ChristianityToday.comhttp://www.christianitytoday.com/history/issues/issue-67/