Pelagius seems to have been already somewhat softened by increasing age when he came to Rome about the opening of the fifth century. He was also constitutionally averse to controversy. In his zeal for Christian morals, and in his conviction that no man would attempt to do what he was not persuaded he had natural power to perform, he diligently propagated his doctrines privately. But he was careful to arouse no opposition, and was content to make what progress he could quietly and without open discussion. His methods of work sufficiently appear in the pages of his Commentary on the Epistles of Saint Paul, which was written and published during these years, and which exhibits learning and a sober and correct but somewhat shallow exegetical skill. In this work, he manages to give expression to all the main elements of his system. But he always introduces them indirectly, not as the true exegesis but by way of objections to the ordinary teaching which were in need of discussion. The most important fruit of his residence in Rome was the conversion to his views of the Advocate Cœlestius, who brought the courage of youth and the argumentative training of a lawyer to the propagation of the new teaching. It was through him that it first broke out into public controversy, and received its first ecclesiastical examination and rejection. Fleeing from Alaric’s second raid on Rome, the two friends landed together in Africa (A.D. 411), whence Pelagius soon afterwards departed for Palestine, leaving the bolder and more contentious1 Cœlestius behind at Carthage. Here Cœlestius sought ordination as a presbyter. But the Milanese deacon Paulinus stood forward in accusation of him as a heretic, and the matter was brought before a synod under the presidency of Bishop Aurelius.2
Paulinus’ charge consisted of seven items,3 which asserted that Cœlestius taught the following heresies: that Adam was made mortal, and would have died whether he sinned or did not sin; that the sin of Adam injured himself alone, not the human race; that newborn children are in that state in which Adam was before his sin; that the whole human race does not, on the one hand, die on account of the death or the fall of Adam, nor, on the other, rise again on account of the resurrection of Christ; that infants, even though not baptized, have eternal life; that the law leads to the kingdom of heaven in the same way as the gospel; and that, even before the Lord’s coming, there had been men without sin. Only two fragments of the proceedings of the synod in investigating this charge have come down to us.4 But it is easy to see that Cœlestius was contumacious and refused to reject any of the propositions charged against him, except the one which had reference to the salvation of infants that die unbaptized,—the sole one that admitted of sound defence. As touching the transmission of sin, he would only say that it was an open question in the Church, and that he had heard both opinions from Church dignitaries; so that the subject needed investigation, and should not be made the ground for a charge of heresy. The natural result was, that, on refusing to condemn the propositions charged against him, he was himself condemned and excommunicated by the synod. Soon afterwards he sailed to Ephesus, where he obtained the ordination which he sought.
Meanwhile Pelagius was living quietly in Palestine, whither in the summer of 415 a young Spanish presbyter, Paulus Orosius by name, came with letters from Augustine to Jerome, and was invited, near the end of July in that year, to a diocesan synod presided over by John of Jerusalem. There he was asked about Pelagius and Cœlestius, and proceeded to give an account of the condemnation of the latter at the synod of Carthage, and of Augustine’s literary refutation of the former. Pelagius was sent for, and the proceedings became an examination into his teachings. The chief matter brought up was his assertion of the possibility of men living sinlessly in this world. But the favour of the bishop towards him, the intemperance of Orosius, and the difficulty of communication between the parties arising from difference of language, combined so to clog proceedings that nothing was done; and the whole matter, as Western in its origin, was referred to the Bishop of Rome for examination and decision.5