Novatian, a priest of the Church in Rome, a convert from paganism, who in the third century took a severe view of the conduct of those who had lapsed under persecution, particularly the Decian, and insisted that the Church, having no power to absolve them, could not, even on penitence, readmit them, in which protest he was joined by a considerable party named after him Novatians, and who continued to trouble the Church for centuries after his death, assuming the name of Cathari or purists.