Pelagianism the doctrine in Christian theology that, through the exercise of free will, human beings can attain moral perfection. A broad movement devoted to this proposition was only loosely associated with its eponymous leader. Pelagius (c.354–c.425), a lay theologian from Britain or Ireland, taught in Rome prior to its sacking in 410. He and his disciple Celestius found a forceful adversary in Augustine, whom they provoked to stiffen his stance on original sin, the bondage of the will, and humanity’s total reliance upon God’s grace and predestination for salvation. To Pelagius, this constituted fatalism and encouraged moral apathy. God would not demand perfection, as the Bible sometimes suggested, were that impossible to attain. Rather grace made the struggle easier for a sanctity that would not be unreachable even in its absence. Though in the habit of sinning, in consequence of the fall, we have not forfeited the capacity to overcome that habit nor been released from the imperative to do so. For all its moral earnestness this teaching seems to be in conflict with much of the New Testament, especially as interpreted by Augustine, and it was condemned as heresy in 418. The bondage of the will has often been reaffirmed, perhaps most notably by Luther in dispute with Erasmus. Yet Christian theology and practice have always had their sympathizers with Pelagianism and with its reluctance to attest the loss of free will, the inevitability of sin, and the utter necessity of God’s grace. A.E.L.