Pelagius the heresiarch.
Pelagius 2649 the heresiarch, before he was proclaimed a heretic wrote works of practical value for students: three books On belief in the Trinity, and one book of Selections from Holy Scriptures bearing on the Christian life. This latter was preceded by tables of contents, after the model of Saint Cyprian the martyr. After he was proclaimed heretic, however, he wrote works bearing on his heresy.