SIMPLICIAN, bishop of Milan, saint. — Probably of Milanese origin, he was a priest in Milan and from 397 succeeded St. Ambrose in the episcopal see; he died on 15 July 400. He baptized St. Ambrose (Augustine, Conf., VIII, 2, 3) and his assistant.
Letters (Epp. 37, 38, 65, 67) of Ambrose to S. have been preserved, while those of S. to Ambrose have been lost, as have those he wrote to St. Augustine, still a priest, in which he exhorted him: «agitate ingenuum et expositioni scripturarum vacare» (Gennadius, De viris illustr., 36 [37]). Augustine’s correspondence includes one letter to S. (Epp., 37); moreover, St. Augustine dedicated to him the work De diversis quaestionibus ad Simplicianum libri, which he wrote in 396. S. was in the 4th century a leading figure, not only because of his relations with St. Augustine, but also because he had taken part in the latter’s conversion and that of C. M. Victorinus ([v.] cf. Augustine, Conf., VIII, 11, 3). S., who had traveled widely, was a learned theologian, acquainted also with Neoplatonic philosophy. Pope Anastasius I (Epp. ad Simplician.: PL 20, 74) sought to induce him to take measures against the followers of Origen, but S. died before reaching a decision (400 or 401). His decision would probably not have differed greatly from that of his successor Venerius, who, while condemning the errors of Origen, refused to condemn Rufinus as well. There exists a letter of Virgilius of Trent (v.) In laudem martyrum, i.e. of the martyrs of Trent, Sisinnus and companions (PL 20, 74), addressed to S., and synodal acts from Carthage (a. 397; cf. Mansi, III, 801) and Toledo (a. 400; ibid., 945, 1007). The tomb of S. is found in the Basilica built by him for the relics of St. Sisinnus and companions. Feast: 16 Aug.