PELAGIUS (d. 418) was a Christian monk whose name has become synonymous with doctrines of human cooperation in salvation at the expense of divine grace. The historical figure is more complex than the teachings associated with his name. Pelagius was born in Britain in the middle of the fourth century. Nothing is known of his background or upbringing, but he seems to have received an excellent education. He was highly regarded for his exemplary life, and even his great opponent, Augustine of Hippo, acknowledged that he was a "holy man who had made no small progress in the Christian life." He went to live in Rome sometime toward the end of the fourth century, perhaps as early as the 380s.

Pelagius was first and foremost a monk and an ascetic, a tutor to men and women seeking the life of perfection. His primary concern was moral and spiritual, not...