PETREIUS (PEETERS), THEODORUS. - Carthusian, b. at Kempen on 17 Apr. 1560, d. at Cologne on 24 Apr. 1640. He studied philosophy at Cologne, where he entered religious life in 1587. Prior of the Charterhouse of Dülmen (1612–19), he took part twice in the General Chapter of his Order.
His output was extensive, though not always critical. Principal works: Confessio Gregoriana (Cologne 1597, 1605); refutation of errors through the words of St. Gregory, Confessio Tertulliana et Cyprianiana, with the addition of Antidota pro eadem confessione adversus impias lutheranorum et calvinistarum criminationes (Paris 1603); Confessio b. Leonis Magni (Cologne 1604); Confessio Bernardina (ibid. 1606; 1607); Harmonica quattuor Occidentalis Ecclesiae doctorum confessio (ibid. 1610). In 1640 he edited, in 3 vols., the complete works of St. Bruno. Among his minor works were various writings concerning the history and discipline of his Order, and Latin translations of various ascetical-apologetic works by the Jesuits F. Coster and J. David.