Pelagius was a Welsh cleric, active in Rome, North Africa, and the Middle East at the beginning of the 5th century. He denied the transmission of original sin, and denied that baptism is necessary to be freed from it. He held the view that man can take the first steps to his own salvation without the assistance of divine grace, and was one of the principal targets of Augustine who had his doctrine declared heretical in 416. The dispute rumbled on, but the declaration was upheld at the Council of Ephesus in 431.
Philosophy dictionary. Academic. 2011.