It will save lengthy digression if we at once speak of a document which will often have to be referred to on account of its biographical importance, viz., the letter written by Eusebius to his diocese in order to explain his subscription to the Creed propounded by the Council of Nicæa. After some preliminary remarks, the writer proceeds: "We first transmit to you the writing concerning the faith which was put forward by us, and then the second, which they have published after putting in additions to our expressions. Now the writing presented by us, which when read in the presence of our most religious emperor was declared to have a right and approved character was as follows: [The Faith put forward by us]. As we have received from the bishops before us both in our first catechetical instruction and when we were baptized, and as we have learned from the Divine Scriptures, and as we have believed and taught in the presbyterate and in the office of bishop itself so now likewise believing we offer to you our faith and it is thus." Then follows a formal creed [Theodoret, Hist., I, 11; Socrates, Hist., I, 8; St. Athanasius, de Dec. Syn. Nic. (appendix) and elsewhere. Translated by Newman with notes in the Oxford Library of the Fathers (Select Treatises of St. Athanasius, p. 59) and St. Athanasius, vol. I. The translation given here is Dr. Hort's. The words in brackets are probably genuine though not given by Socrates and St. Athanasius].
Alexander, Bishop of Alexandria, excommunicated Arius about the year 320. The Arians soon found that for all practical purposes Eusebius was on their side. He wrote to Alexander charging him with misrepresenting the teaching of the Arians and so giving them cause "to attack and misrepresent whatever they please" (see below). A portion of this letter has been preserved in the Acts of the second Council of Nicæa, where it was cited to prove that Eusebius was a heretic. He also took part in a synod of Syrian bishops who decided that Arius should be restored to his former position, but on his side he was to obey his bishop and continually entreat peace and communion with him (Soz., H. E., I, 15). According to Duchesne (Hist. de l'Eglise, II, 132), Arius, like Origen before him, found an asylum at Cæsarea. At the opening of the Council of Nicæa Eusebius occupied the first seat on the right of the emperor, and delivered the inaugural address which was "couched in a strain of thanksgiving to Almighty God on his, the emperor's behalf" (Vit. Const., III, 11; Soz., H. E., I, 19). He evidently enjoyed great prestige and may not unreasonably have expected to be able to steer the council through the via media between the Scylla and Charybdis of "Yes" and "No". But if he entertained such hopes they were soon disappointed. We have already spoken of the profession of faith which he brought forward to vindicate his own orthodoxy, or perhaps in the hope that the council might adopt it. It was, in view of the actual state of the controversy, a colourless, or what at the present day would be called a comprehensive, formula. After some delay Eusebius subscribed to the uncompromising creed drawn up by the council, making no secret, in the letter which he wrote to his own Church, of the non-natural sense in which he accepted it. Between 325 and 330 a heated controversy took place between Eusebius and Eustathius, Bishop of Antioch. Eustathius accused Eusebius of tampering with the faith of Nicæa; the latter retorted with the charge of Sabellianism. In 331 Eusebius was among the bishops who, at a synod held in Antioch, deposed Eustathius. He was offered and refused the vacant see. In 334 and 335 he took part in the campaign against St. Athanasius at the synods held in Cæsarea and Tyre respectively. From Tyre the assembly of bishops were summoned to Jerusalem by Constantine, to assist at the dedication of the basilica he had erected on the site of Calvary. After the dedication they restored Arius and his followers to communion. From Jerusalem they were summoned to Constantinople (336), where Marcellus was condemned. The following year Constantine died. Eusebius survived him long enough to write his Life and two treatises against Marcellus, but by the summer of 341 he was already dead, since it was his successor, Acacius, who assisted as Bishop of Cæsarea at a synod held at Antioch in the summer of that year.
Dr. Hort in 1876 ("Two Dissertations", etc., pp. 56 sqq.) pointed out that this creed was presumably that of the Church of Cæsarea of which Eusebius was bishop. This view is widely accepted (cf. Lightfoot, art. "Euseb." in "Dict. of Christ. Biog." — All references to Lightfoot, unless otherwise stated, are to this article. — Sanday, "Journal of Theolog. Studies", vol. I, p. 15; Gwatkin, "Studies of Arianism", p. 42, 2nd edition; McGiffert, "Prolog. to C. H. of Euseb." in "Select Library of Nic. and post-Nic. Fathers"; Duchesne, "Hist. de l'Eglise", vol. II, p. 149). According to this view it is natural to regard the introduction, "As we have received" etc., as autobiographical, and to infer that Eusebius had exercised the office of priesthood in the city of Cæsarea before he became its bishop, and had received his earliest religious instruction and the sacrament of Baptism there also.
18) The labours of Pamphilus and Eusebius in editing the Septuagint have already been spoken of. They "believed (as did St. Jerome nearly a century afterwards) that Origen had succeeded in restoring the old Greek version to its primitive purity". The result was a "mischievous mixture of the Alexandrian version with the versions of Aquila and Theodotion" (Swete, "Introd. to O. T. in Greek", pp. 77, 78). For the labours of the two friends on the text of the N. T. the reader may be referred to Rousset, "Textcritische Studien zum N. T.", c. ii. Whether as in the case of the Old Testament, they worked on any definite critical principles is not known.