Eustathius (4) , bp. of Sebaste (the modern Siwas ) in Pontus, on the N. bank of the Halys, the capital of Armenia Minor (c. a.d. 357-380). Eustathius occupies a place more conspicuous than honourable in the unhappy dissensions between the adherents of the orthodox faith and the various shades of Arian, semi-Arian, and Anomoean heresy during the middle of the 4th cent. Originally a disciple of Arius, after repeated approaches to the Nicene faith, with occasional professions of accepting it, he probaby ended his days as a Eunomian heretic (Basil. Ep. 244 , Â§ 9). Few in that epoch of conflicting creeds and formularies ever signed more various documents. Basil enumerates his signature of the formularies of Ancyra, Seleucia, Constantinople, Lampsacus, Nice in Thrace, and Cyzicus, which are sufficiently diverse to indicate the vagueness of his theology (Basil. l.c. ). Eustathius thus naturally forfeited the confidence of all schools of theology. His personal character appears to have been high. There must have been something more than common in a man who could secure the affection and respect for many years of Basil the Great, as, in Basil's own strong language, "exhibiting something more than man" (Ep. 212 , Â§ 2). As bishop he manifested his care for the sick and needy, and was unwearied in the fulfilment of duty. The system of coenobitic monasticism introduced by him into Asia Basil took as his model (Soz. H. E. iii. 14; Basil. Ep. 223 , Â§ 3).
Eustathius was born in the Cappodocian Caesarea towards the beginning of the 4th cent. He studied at Alexandria under the heresiarch Arius (c. a.d. 320) (Basil. Ep. 223 , Â§ 3; 244 , Â§ 9; 263 , Â§ 3). On leaving Alexandria he repaired to Antioch, where he was refused ordination on account of his Arian tenets by his orthodox namesake (Athan. Solit. p. 812). He was afterwards ordained by Eulalius ( c. 331), but very speedily degraded by him for refusing to wear the clerical dress (Socr. H. E. ii. 43; Soz. H. E. iv. 24). From Antioch Eustathius returned to Caesarea, where he obtained ordination from the orthodox bp. Hermogenes, on declaring his unqualified adhesion to the Nicene faith (Basil. Ep. 244 , Â§ 9; 263 , Â§ 3). On the death of Hermogenes, Eustathius repaired to Constantinople and attached himself to Eusebius, the bishop there, "the Coryphaeus of the Arian party" (Basil. ll.cc. ). By him he was a second time deposed (c. a.d. 342) on the ground of some unspecified act of unfaithfulness to duty (Soz. H. E. iv. 24). He retired again to Caesarea, where, carefully concealing his Arian proclivities, he sought to commend himself to the bishop, Dianius. His subsequent history till he became bp. of Sebaste is almost a blank. We must, however, assign to it the theological argument held by him and Basil of Ancyra with the audacious Anomoean, Aetius, who is regarded by Basil as in some sense Eustathius's pupil (Basil. Ep. 123, Â§ 5). It was certainly during this period that Eustathius and his early friend the presbyter Aerius founded coenobitic monachism in Armenia and the adjacent provinces (Epiphan. Haer. 75, Â§ 2). The rule laid down by him for the government of his religious communities of both sexes contained extravagances alluded to by Socrates and Sozomen, which are not unlikely to have been the cause, otherwise unknown, of his excommunication by the council of Neo-Caesarea (Socr. H. E. ii. 43; Soz. H. E. iv. 24). While Eustathius was regulating his coenobitic foundations ( c. 358) he was visited by Basil, who records the delight with which he saw the coarse garments, the girdle, the sandals of undressed hide, and witnessed the self-denying and laborious lives of Eustathius and his followers. His admiration for such a victory over the world and the flesh dispelled all suspicions of Arian sentiments, and the desire to spread them secretly, which had been rumoured (Basil. Ep. 223 , Â§ 3). After Basil had retired to the banks of the Iris and commenced his own monastic life, he and his brother Gregory received frequent visits from Eustathius, who, with them, would visit Annesi, the residence of their mother Macrina, and spend there whole days and nights in friendly theological discussion ( ib. Â§ 5).
Eustathius's episcopate must have begun before 357, when Athanasius speaks of him as a bishop (Athan. Orat. in Arian. i. p. 290; Solit. p. 812). He was made bp. of Sebaste, according to the same authority, by the Arian party, who hoped to find him an able and facile instrument. His early companion Aerius was a candidate for the bishopric, and felt very mortified by his failure. Eustathius shewed him the utmost consideration, ordained him presbyter, and appointed him manager of a refuge for the poor, the foundation of which was one of the first acts of his episcopate. The final rupture between them is detailed under Aerius. Somewhere about this time we may place Eustathius's conviction of perjury in the council of Antioch (see Socr. H. E. iv. 24), and his deposition by the obscure council of Melitene in Armenia c. a.d. 357 (Basil. Ep. 263 ). Neither of these events appears to have entailed any lasting consequences. Eustathius was one of the prelates at the semi-Arian synod summoned at Ancyra by George of Laodicea, before Easter a.d. 358, to check the alarming spread of Anomoean doctrines, and he, with Basil of Ancyra and Eleusius of Cyzicus, conveyed the synodal letter, equally repudiating the Anomoean and Homoousian doctrines, and declaring for the Homoiousion, to Constantius at Sirmium (Soz. H. E. iv. 13, 14; Basil. Ep. 263 , Â§ 3). When the council met at Seleucia on Sept. 27, 359, Eustathius occupied a prominent place in its tumultuous and indecisive proceedings, and was the head of the ten episcopal deputies, Basil of Ancyra, Silvanus of Tarsus, and Eleusius of Cyzicus being other chief members, sent to Constantinople to lay their report before Constantius. Stormy discussions followed, in which Eustathius led the semi-Arians as against the pure Arians. He vehemently denounced the blasphemies of the bold Anomoean, Eudoxius, bp. of Antioch, and produced a formulary of faith declaring the dissimilarity of the Father and the Son, which he asserted to be by Eudoxius. All seemed to augur the triumph of orthodoxy when the arrival of Valens and Ursacius from Ariminum announcing the subjugation of the Western bishops and the general proscription of the Homoousion suddenly changed the scene. Constantius was overjoyed at the unexpected success, and after a protracted discussion, compelled Eustathius and the other Seleucian deputies to sign the fatal formulary. It was then, in Jerome's words, "ingemuit totus orbis et se esse Arianum miratus est" (Hieron. in Lucif. 19). This base concession profited the recreants little. The emperor summoned a synod, of which Acacius was the ruling spirit, at Constantinople in Jan. 360. Eustathius was deposed in a tyrannical manner, with Cyril of Jerusalem, Basil of Ancyra, Eleusius of Cyzicus, and other important prelates. Eustathius was not even allowed to defend himself. His former deposition by Eulalius was held sufficient (Socr. H. E. ii. 41-43; Soz. H. E. iv. 24). Constantius confirmed the sentence, exiled the bishops, and gave their sees to others. The death of Constantius in 361 and the accession of Julian witnessed the recall of Eustathius with the other banished bishops. He immediately repudiated his signature to the creed of Ariminum, and did all he could to shew his horror of pure Arianism. Sozomen tells us that, with Eleusius, Sophronius, and others of like mind, he held several synods, condemning the partisans of Acacius, denouncing the creed of Ariminum, and asserting the Homoiousion as the true mean between the Homoousion of the West and the Anomoeon of Aetius and his followers ( H. E. v. 14). With the accession of Valens in 364, Arianism once more assumed ascendancy in the East. The semi-Arian party, or Macedonians as they now began to be called, met by imperial permission in council at Lampsacus a.d. 365, under the presidency of Eleusius, and repudiated the Acacian council of Constantinople (360) and the creed of Ariminum, renewed the confession of Antioch ( In Encaeniis ), and pronounced sentence of deposition on Eudoxius and Acacius (Socr. H. E. iv. 2-4; Soz. H. E. vi. 7). These proceedings irritated Valens, who required them to hold communion with Eudoxius, and, on their refusal, sentenced them to fine and banishment, giving their sees to others. To escape annihilation, the Macedonians sent deputies, Eustathius being one, to the Western emperor Valentinian and Liberius, bp. of Rome, who had repented his lapse in a.d. 357, offering to unite with them in faith. Before they arrived, Valentinian had left for Gaul, and Liberius, at first looking coldly on them as Arians, refused to receive them. On their giving a written adhesion to the Nicene Creed and the Homoousion, he received them into communion, and gave them letters in his name and that of the Western church to the prelates of the East, expressing his satisfaction at the proof he had received of the identity of doctrine between East and West (Socr. H. E. iv. 12; Soz. H. E. vi. 11). No mention was made of the new Macedonian heresy concerning the Holy Spirit, now infecting the Eastern church, of which Eustathius and the other deputies were among the chief promulgators. Eustathius and his companions at once repaired to Sicily, where a synod of bishops, on their profession of orthodoxy, gave them letters of communion. They then returned to their own country. A synod of orthodox bishops was assembled in 367 at Tyana, to receive the letters of communion from the West and other documents (Soz. l.c.; Basil. Ep. 244 , Â§ 5). Eustathius and his fellow-delegates, now recognized as true Catholics, were acknowledged as the rightful bishops of their sees. A council summoned at Tarsus to consolidate this happy reunion was prohibited by Valens, who, having committed himself to the Arian party, issued an edict expelling all bishops restored by Julian. Eustathius, to save himself, signed a formula at Cyzicus of Homoiousian character, which also denied the divinity of the Holy Spirit. Basil says tersely of Eustathius and his party, "they saw Cyzicus and returned with a different creed" (Basil. u.s. and Â§ 9; 226 ).
On Basil's elevation to the episcopate in 370 Eustathius exhibited great joy, and professed an earnest desire to be of service to his friend. He recommended persons as fellow-helpers who, as Basil bitterly complains, turned out to be spies of his actions and words, interpreting all in a malevolent sense and reporting to their chief (ib. 223 , Â§ 3). For their subsequent bitter relations, see Basilius of Caesarea. Eustathius heaped calumnies on the head of his former associate, openly charging him with Apollinarian and other heretical views, and encouraged the clergy of his diocese and province to form a rival communion. Demosthenes, the Vicar of the Prefect, an old enemy of Basil, strenuously forwarded this object. In 376 he visited Sebaste and other chief places in the province, oppressing Basil's adherents, whom he compelled to undertake onerous and costly public duties, and loading the followers of Eustathius with the highest honours ( ib. 237 , Â§ 2). Eustathius, seeing Arianism in the ascendant, openly sought communion with those whom he had repeatedly denounced. His deposition at Constantinople was not forgotten by the Arians, who had not hitherto recognized him as a canonical bishop. He now sought their goodwill by humiliating concessions. He had overthrown the altars of Basilides, bp. of Gangra, as an Arian, but now begged admission to his communion. He had treated the people of Amasea as heretics, excommunicating Elpidius for holding intercourse with them, and now earnestly sought their recognition. At Ancyra, the Arians refusing him public recognition, he submitted to communicate with them in private houses. When the Arian bishops met in synod at Nyssa he sent a deputation of his clergy to invite them to Sebaste, conducted them through the province with every mark of honour, allowed them to preach and celebrate the Eucharist in his churches, and withheld no mark of the most intimate communion ( ib. 257 , Â§ 3). These humiliations had but tardy and partial success in obtaining his public acknowledgment by the dominant ecclesiastics. His efforts to secure Arian favour and his effrontery in trading upon his former recognition by Liberius extorted from Basil a vehement letter of remonstrance, addressed to the bp. of Rome and the other Western bishops, depicting the evils inflicted on the Eastern church by the wolves in sheep's clothing, and requesting Liberius to declare publicly the terms on which Eustathius had been admitted to communion ( ib. 263 , Â§ 3). All Basil's efforts to obtain this mark of sympathy and brotherly recognition from the West were fruitless. He continued to be harassed by the unscrupulous attacks of Eustathius till his death in 379. If the see was vacated by his death, and not, as Hefele holds, with much probability, by his deposition at Gangra, Eustathius died soon after. In 380 Peter became bp. of Sebaste, and thus Basil's brother replaced Basil's most dangerous enemy.
The synod of Gangra, of uncertain date [D. C. A., s.v. ], is intimately connected with the name of Eustathius. The identity of the Eustathius there condemned with the bp. of Sebaste, though affirmed by every ancient authority, has been denied by Blondel (De la primautÃ©, p. 138), Baronius ( Annal. iii. ann. 361, n. 53), Du Pin ( Nouvelle bibliothÃ¨que, ii. 339) and called in question by Tillemont ( MÃ©m. eccl. ix. note 28, S. Basile ); but on careful investigation Hefele (Hist. of the Church Councils, ii. 325 ff. Engl. trans.) scouts the idea that another Eustathius is intended. C. F. Loots Eust. of Seb., Halle, 1898.