A more dangerous error, though purely local in its immediate surroundings, was the denial of the validity of Baptism when conferred by heretics. This contention had occasioned a schism in the church of Africa since the beginning of the fourth century. It received the name of Donatism from Donatus, schismatic Bishop of Carthage, who had been aided by another Donatus of Casae Nigrae. In St. Augustine's time it had spread over the whole country. The Saint put forward the true idea of the Church and showed that the minister of a sacrament does not communicate to the recipient his own character of holiness or of guilt, that it is Christ Himself who baptizes and absolves and gives efficacy to sacramental signs. The cogency of his words, the clearness of his explanations, and his grace of manner led many of the Donatists to desire union with the Church, which he showed them, as Christ's Body, is one and indivisible. His chief works in this controversy are a letter to Maximinus, a Donatist bishop whom he brought back to Catholic Unity, the "Christian Combat," the "One Baptism," three books against Parmeian, letter to Glorius and three others, and a conference with Bishop Fortunatus, at Turbusum. As if by divine inspiration he had laid down in a work on "Free Will," which he had begun at Rome, enlarged at Tagasta, and completed in 395, principles which afford sufficient answer to the errors of Pelagianism. This heresy broached novel teachings on man, the fall, and the state in which that fall had left the human race. St. Augustine, who had not been able to take part in the council of Carthage, where Pelagius was first condemned, brought out in clear light the true doctrine and nature and action of supernatural grace, and the effects of original sin on man's will and heart. His treatises on "Merit" and the "Remission of Sins," explained all the weakness of fallen nature, the need of divine grace to perform actions that conduce to eternal life, and the necessity and place of human effort in the work of justification and faith. As it was asserted that children should not be baptized because the sin of Adam was not transmitted to them, he wrote a book on the "Baptism of Children." In "Nature and Grace" and "Faith and its Works," "On the Grace of Jesus Christ" and "Original Sin," still further explanation and argument are given to establish Catholic truth.