Pelagianism (pəlāˈjənĭzəm) [key], Christian heretical sect that rose in the 5th cent. challenging St. Augustine's conceptions of grace and predestination. The doctrine was advanced by the celebrated monk and theologian Pelagius (c.355–c.425). He was probably born in Britain. After studying Roman law and rhetoric and later theology in England and Rome, he preached in Africa and Palestine, attracting able followers, such as Celestius and Julian of Eclannum. Pelagius thought that St. Augustine was excessively pessimistic in his view that humanity is sinful by nature and must rely totally upon grace for salvation. Instead Pelagius taught that human beings have a natural capacity to reject evil and seek God, that Christ's admonition, "Be ye perfect," presupposes this capacity, and that grace is the natural ability given by God to seek and to serve God. Pelagius rejected the doctrine of original sin; he taught that children are born innocent of the sin of Adam. Baptism, accordingly, ceased to be interpreted as a regenerative sacrament. Pelagius challenged the very function of the church, claiming that the law as well as the gospel can lead one to heaven and that pagans had been able to enter heaven by virtue of their moral actions before the coming of Christ. The church fought Pelagianism from the time that Celestius was denied ordination in 411. In 415, Augustine warned St. Jerome in Palestine that Pelagius was propagating a dangerous heresy there, and Jerome acted to prevent its spread in the East. Pelagianism was condemned by East and West at the Council of Ephesus (431). A compromise doctrine, Semi-Pelagianism, became popular in the 5th and 6th cent. in France, Britain, and Ireland. Semi-Pelagians taught that although grace was necessary for salvation, men could, apart from grace, desire the gift of salvation, and that they could, of themselves, freely accept and persevere in grace. Semi-Pelagians also rejected the Augustinian doctrine of predestination and held that God willed the salvation of all men equally. At the instance of St. Caesarius of Arles, Semi-Pelagianism was condemned at the Council of Orange (529). By the end of the 6th cent., Pelagianism disappeared as an organized heresy, but the questions of free will, predestination, and grace raised by Pelagianism have been the subject of theological controversy ever since (see Molina, Luis; Arminius, Jacobus). Pelagius' Expositions of Thirteen Epistles of St. Paul was edited in English by Alexander Souter (3 vol., 1922–31).
See J. E. Chisholm, The Pseudo-Augustinian Hypomnesticon against the Pelagians and Celestinans (Vol. I, 1967); J. Pelikan, The Emergence of the Catholic Tradition (1971).