Sixtus III., bp. of Rome

Sixtus III., bp. of Rome (432–441) after Coelestinus, and the immediate predecessor of Leo the Great. Two notable heresies of his day were Pelagianism and Nestorianism. Before his accession he had taken part in both controversies. It appears from Augustine's letters 912to him when he was still a Roman presbyter under Zosimus, that the Pelagians had claimed him as being, with the pope, on their side; but that, when the pope was at length induced to condemn the heresy, he also had written to the African church expressing his concurrence with a vigour of language that fully satisfied Augustine, who also rejoices to have heard that he had been foremost in anathematizing Pelagianism in a large assembly at Rome (Aug. Epp. 191, al. 104, and 194, al. 105). Apparently Sixtus had, before his accession, also intervened in the Nestorian conflict, for in his letter to John of Antioch (Ep. ii.) he speaks of having once admonished Nestorius; and this must have been before the latter's final condemnation, and hence before the accession of Sixtus, who was evidently a man of mark and influence at Rome before becoming pope.

It seems, however, that the Nestorians as well as the Pelagians claimed Sixtus as once having favoured them; and he was reported to have taken in ill part the condemnation of Nestorius. These claims may have arisen from his having evinced a conciliatory spirit and a reluctance to condemn too hastily.

There are two extant epistles of his, written to Cyril and John of Antioch, expressing his great joy in their reconciliation; from one of which it further appears that he had written often previously to Maximian, the successor of Nestorius at Constantinople. A synod had been held at Rome on the occasion of his birthday, at which the joyful news of the reconciliation had been made known, and he was, when he wrote, expecting the speedy arrival of a deputation of clergy from John of Antioch. These two letters are given by Baronius (A.D. 433, xii. and xvii.); from a Vatican MS., which he speaks of as corrupt but trustworthy. (See also Labbe, Concil. Eph. iii. 1689, 1699.) The letter to John is quoted by Vincent of Lerins (adv. Haer.).

Two previous letters of Sixtus, conceived in a similar spirit, are given by Cotelerius from MSS. in the Biblioth. Reg. (Coteler. Monum. Graec. Eccles. vol. i. p. 42). One was to Cyril; the other was apparently an encyclic to him and the Easterns generally, sent by two bishops from the East, Hermogenes and Lampetius, who had been present at the pope's ordination. Both announced, as was usual, his accession to his see, and declared his communion with the Eastern churches. But in both, while he fully concurs in the condemnation of Nestorius by the council of Ephesus, he refers with regret to the dissent of John of Antioch and his adherents, whose reception into communion he desires and recommends, if they should come to a better mind, as he hopes they will.

Sixtus was no less vigilant than preceding popes in maintaining the jurisdiction of the Roman see over Illyricum, and that of the bp. of Thessalonica as the pope's vicar over the rest of the bishops there. Four letters of his (two written in 435, another in 437) on this subject were read in the Roman council held under Boniface II., a.d. 531. (See Labbe, vol. v., Concil. Rom. III. sub Bonifac. II.) In the fourth, addressed to all the bishops of Illyricum, he enjoins them to submit themselves to Anastasius of Thessalonica as, like his predecessor, vicar of the apostolic see, with authority to summon synods and adjudicate on all cases, except such as it might be necessary to refer to Rome. He bids them pay no regard to the decrees of "the oriental synod," except those on faith, which had his own approval. He probably refers to the council of Constantinople, which in its 3rd canon had given a primacy of honour after old Rome to Constantinople. On the strength of this the patriarchs of Constantinople had already assumed jurisdiction over the Thracian dioceses, though not till the council of Chalcedon (A.D. 451; can. xxviii.) was the express power of ordaining metropolitans in Illyricum formally given to them, despite the protest of pope Leo's legates.

Towards the end of his life Sixtus still concurred decidedly in the condemnation of Pelagianism. For we are told by Prosper (Chron.) that Julian, the eminent Pelagian, being deposed from the see of Eclanum in Campania, essayed in 439, by profession of penitence, to creep again into the communion of the church, but that Sixtus, under the advice of his deacon Leo, "allowed no opening to his pestiferous attempts." This Leo was the successor of Sixtus in the see of Rome, Leo the Great, who thus appears to have been his archdeacon and adviser.

Three works issued under the name of Sixtus (de Divitiis, de Malis Doctoribus, etc., and de Castitate) are apparently of Pelagian origin (see Baron. ad ann. 440, vi.), possibly put out in his name on the strength of the old report of his having once favoured Pelagianism.

Sixtus died a.d. 440, and was buried (according to Anastasius, Lib. Pontif.), "ad S. Laurentium via Tiburtini." He is commemorated as a confessor on Mar. 28: "Romae S. Sixti tertii, papae et confessoris" (Martyrol. Roman). Why he should be called a confessor is not obvious. The title may rest on a spurious letter to the bishops of the East, which complains of persecution.

In the Lib. Pontif. extraordinary activity in building, endowing, and decorating churches is attributed to him, and to the emperor Valentinian under his instigation. He is said to have built the basilicas of St. Maria Maggiore on the Esquiline (called Ad Praesepe), and of St. Laurence, and to have furnished both with great store of precious instruments and ornamentations. Pope Hadrian, in writing to Charlemagne (Ep. 3, c. 19) alludes to the former.

[J.B—Y.]