Socrates (H. E. I. 5 sq.), Sozomen (H. E. I. 15) and Theodoret (H. E. I. 2 sq.), all of whom give accounts of the rise of Arianism, differ as to the immediate occasion of the controversy, but agree that Arius was excommunicated by a council convened at Alexandria, and that both he and the bishop Alexander sent letters to other churches, the latter defending his own course, the former complaining of his harsh treatment, and endeavoring to secure adherents to his doctrine. Eusebius of Nicomedia at once became his firm supporter, and was one of the leading figures on the Arian side throughout the entire controversy. His influential position as bishop of Nicomedia, the imperial residence, and later of Constantinople, was of great advantage to the Arian cause, especially toward the close of Constantine's reign. From a letter addressed by this Eusebius to Paulinus of Tyre (Theodoret, H. E. I. 6) we learn that Eusebius of Cæsarea was quite zealous in behalf of the Arian cause. The exact date of the letter we do not know, but it must have been written at an early stage of the controversy. Arius himself, in an epistle addressed to Eusebius of Nicomedia (Theodoret, H. E. I. 5), claims Eusebius of Cæsarea among others as accepting at least one of his fundamental doctrines ("And since Eusebius, your brother in Cæsarea, and Theodotus, and Paulinus, and Athanasius, and Gregory, and Ætius, and all the bishops of the East say that God existed before the Son, they have been condemned," etc.). More than this, Sozomen (H. E. I. 15) informs us that Eusebius of Cæsarea and two other bishops, having been appealed to by Arius for "permission for himself and his adherents, as he had already attained the rank of presbyter, to form the people who were with them into a church," concurred with others "who were assembled in Palestine," in granting the petition of Arius, and permitting him to assemble the people as before; but they "enjoined submission to Alexander, and commanded Arius to strive incessantly to be restored to peace and communion with him." The addition of the last sentence is noticeable, as showing that they did not care to support a presbyter in open and persistent rebellion against his bishop. A fragment of a letter written by our Eusebius to Alexander is still extant, and is preserved in the proceedings of the Second Council of Nicæa, Act. VI. Tom. V. (Labbei et Cossartii Conc. VII. col. 497). In this epistle Eusebius strongly remonstrates with Alexander for having misrepresented the views of Arius. Still further, in his epistle to Alexander of Constantinople, Alexander of Alexandria (Theodoret, H. E. I. 4) complains of three Syrian bishops "who side with them [i.e. the Arians] and excite them to plunge deeper and deeper into iniquity." The reference here is commonly supposed to be to Eusebius of Cæsarea, and his two friends Paulinus of Tyre and Theodotus of Laodicea, who are known to have shown favor to Arius. It is probable, though not certain, that our Eusebius is one of the persons meant. Finally, many of the Fathers (above all Jerome and Photius), and in addition to them the Second Council of Nicæa, directly accuse Eusebius of holding the Arian heresy, as may be seen by examining the testimonies quoted below on p. 67 sq. In agreement with these early Fathers, many modern historians have attacked Eusebius with great severity, and have endeavored to show that the opinion that he was an Arian is supported by his own writings. Among those who have judged him most harshly are Baronius (ad ann. 340, c. 38 sq.), Petavius (Dogm. Theol. de Trin. I. c. 11 sq.), Scaliger (In Elencho Trihæresii, c. 27, and De emendatione temporum, Bk. VI. c. 1), Mosheim (Ecclesiastical History, Murdock's translation, I. p. 287 sq.), Montfaucon (Prælim. in Comment. ad Psalm. c. VI.), and Tillemont (H. E. VII. p. 67 sq. 2d ed.).
On the other hand, as may be seen from the testimonies in Eusebius' favor, quoted below on p. 57 sq., many of the Fathers, who were themselves orthodox, looked upon Eusebius as likewise sound on the subject of the Trinity. He has been defended in modern times against the charge of Arianism by a great many prominent scholars; among others by Valesius in his Life of Eusebius, by Bull (Def. Fid. Nic. II. 9. 20, III. 9. 3, 11), Cave (Lives of the Fathers, II. p. 135 sq.), Fabricius (Bibl. Græc. VI. p. 32 sq.), Dupin (Bibl. Eccles. II. p. 7 sq.), and most fully and carefully by Lee in his prolegomena to his edition of Eusebius' Theophania, p. xxiv. sq. Lightfoot also defends him against the charge of heresy, as do a great many other writers whom it is not necessary to mention here. Confronted with such diversity of opinion, both ancient and modern, what are we to conclude? It is useless to endeavor, as Lee does, to clear Eusebius of all sympathy with and leaning toward Arianism. It is impossible to explain such widespread and continued condemnation of him by acknowledging only that there are many expressions in his works which are in themselves perfectly orthodox but capable of being wrested in such a way as to produce a suspicion of possible Arianistic tendencies, for there are such expressions in the works of multitudes of ancient writers whose orthodoxy has never been questioned. Nor can the widespread belief that he was an Arian be explained by admitting that he was for a time the personal friend of Arius, but denying that he accepted, or in any way sympathized with his views (cf. Newman's Arians, p. 262). There are in fact certain fragments of epistles extant, which are, to say the least, decidedly Arianistic in their modes of expression, and these must be reckoned with in forming an opinion of Eusebius' views; for there is no reason to deny, as Lee does, that they are from Eusebius' own hand. On the other hand, to maintain, with some of the Fathers and many of the moderns, that Eusebius was and continued through life a genuine Arian, will not do in the face of the facts that contemporary and later Fathers were divided as to his orthodoxy, that he was honored highly by the Church of subsequent centuries, except at certain periods, and was even canonized (see Lightfoot's article, p. 348), that he solemnly signed the Nicene Creed, which contained an express condemnation of the distinctive doctrines of Arius, and finally that at least in his later works he is thoroughly orthodox in his expressions, and is explicit in his rejection of the two main theses of the Arians,--that there was a time when the Son of God was not, and that he was produced out of nothing. It is impossible to enter here into a detailed discussion of such passages in Eusebius' works as bear upon the subject under dispute. Lee has considered many of them at great length, and the reader may be referred to him for further information.
A careful examination of them will, I believe, serve to convince the candid student that there is a distinction to be drawn between those works written before the rise of Arius, those written between that time and the Council of Nicæa, and those written after the latter. It has been very common to draw a distinction between those works written before and those written after the Council, but no one, so far as I know, has distinguished those productions of Eusebius' pen which appeared between 318 and 325, and which were caused by the controversy itself, from all his other writings. And yet such a distinction seems to furnish the key to the problem. Eusebius' opponents have drawn their strongest arguments from the epistles which Eusebius wrote to Alexander and to Euphration; his defenders have drawn their arguments chiefly from the works which he produced subsequent to the year 325; while the exact bearing of the expressions used in his works produced before the controversy broke out has always been a matter of sharp dispute. Lee has abundantly shown his Contra Marcel., his De Eccl. Theol., his Thephania (which was written after the Council of Nicæa, and not, as Lee supposes, before it), and other later works, to be thoroughly orthodox and to contain nothing which a trinitarian might not have written. In his Hist. Eccl., Præparatio Evang., Demonstratio Evang., and other earlier works, although we find some expressions employed which it would not have been possible for an orthodox trinitarian to use after the Council of Nicæa, at least without careful limitation to guard against misapprehension, there is nothing even in these works which requires us to believe that he accepted the doctrines of Arius' predecessor, Lucian of Antioch; that is, there is nothing distinctly and positively Arianistic about them, although there are occasional expressions which might lead the reader to expect that the writer would become an Arian if he ever learned of Arius' doctrines. But if there is seen to be a lack of emphasis upon the divinity of the Son, or rather a lack of clearness in the conception of the nature of that divinity, it must be remembered that there was at this time no especial reason for emphasizing and defining it, but there was on the contrary very good reason for laying particular stress upon the subordination of the Son over against Sabellianism, which was so widely prevalent during the third century, and which was exerting an influence even over many orthodox theologians who did not consciously accept Sabellianistic tenets. That Eusebius was a decided subordinationist must be plain to every one that reads his works with care, especially his earlier ones. It would be surprising if he had not been, for he was born at a time when Sabellianism (monarchianism) was felt to be the greatest danger to which orthodox christology was exposed, and he was trained under the influence of the followers of Origen, who had made it one of his chief aims to emphasize the subordination of the Son over against that very monarchianism. [1] The same subordinationism may be clearly seen in the writings of Dionysius of Alexandria and of Gregory Thaumaturgus, two of Origen's greatest disciples. It must not be forgotten that at the beginning of the fourth century the problem of how to preserve the Godhood of Christ and at the same time his subordination to the Father (in opposition to the monarchianists) had not been solved. Eusebius in his earlier writings shows that he holds both (he cannot be convicted of denying Christ's divinity), but that he is as far from a solution of the problem, and is just as uncertain in regard to the exact relation of Father and Son, as Tertullian, Hippolytus, Origen, Dionysius, and Gregory Thaumaturgus were; is just as inconsistent in his modes of expression as they, and yet no more so (see Harnack's Dogmengeschichte, I. pp. 628 sq. and 634 sq., for an exposition of the opinions of these other Fathers on the subject). Eusebius, with the same immature and undeveloped views which were held all through the third century, wrote those earlier works which have given rise to so much dispute between those who accuse him of Arianism and those who defend him against the charge. When he wrote them he was neither Arian nor Athanasian, and for that reason passages may be found in them which if written after the Council of Nicæa might prove him an Arian, and other passages which might as truly prove him an Athanasian, just as in the writings of Origen were found by both parties passages to support their views, and in Gregory Thaumaturgus passages apparently teaching Arianism, and others teaching its opposite, Sabellianism (see Harnack, ib. p. 646).
Let us suppose now that Eusebius, holding fast to the divinity of Christ, and yet convinced just as firmly of his subordination to the Father, becomes acquainted through Arius, or other like-minded disciples of Lucian of Antioch, with a doctrine which seems to preserve the Godhood, while at the same time emphasizing strongly the subordination of the Son, and which formulates the relation of Father and Son in a clear and rational manner. That he should accept such a doctrine eagerly is just what we should expect, and just what we find him doing. In his epistles to Alexander and Euphration, he shows himself an Arian, and Arius and his followers were quite right in claiming him as a supporter. There is that in the epistles which is to be found nowhere in his previous writings, and which distinctly separates him from the orthodox party. How then are we to explain the fact that a few years later he signed the Nicene creed and anathematized the doctrines of Arius? Before we can understand his conduct, it is necessary to examine carefully the two epistles in question. Such an examination will show us that what Eusebius is defending in them is not genuine Arianism. He evidently thinks that it is, evidently supposes that he and Arius are in complete agreement upon the subjects under discussion; but he is mistaken. The extant fragments of the two epistles are given below on p. 70. It will be seen that Eusebius in them defends the Arian doctrine that there was a time when the Son of God was not. It will be seen also that he finds fault with Alexander for representing the Arians as teaching that the "Son of God was made out of nothing, like all creatures," and contends that Arius teaches that the Son of God was begotten, and that he was not produced like all creatures. We know that the Arians very commonly applied the word "begotten" to Christ, using it in such cases as synonymous with "created," and thus not implying, as the Athanasians did when they used the word, that he was of one substance with the Father (compare, for instance, the explanation of the meaning of the term given by Eusebius of Nicomedia in his epistle to Paulinus; Theod. H. E. I. 6). It is evident that the use of this word had deceived our Eusebius, and that he was led by it to think that they taught that the Son was of the Father in a peculiar sense, and did in reality partake in some way of essential Godhood. And indeed it is not at all surprising that the words of Arius, in his epistle to Alexander of Alexandria (see Athan. Ep. de conc. Arim. et Seleuc., chap. II. §3; Oxford edition of Athanasius' Tracts against Arianism, p. 97), quoted by Eusebius in his epistle to the same Alexander, should give Eusebius that impression. The words are as follows: "The God of the law, and of the prophets, and of the New Testament before eternal ages begat an only-begotten Son, through whom also He made the ages and the universe. And He begat him not in appearance, but in truth, and subjected him to his own will, unchangeable and immutable, a perfect creature of God, but not as one of the creatures." Arius' use here of the word "begat," and his qualification of the word "creature" by the adjective "perfect," and by the statement that he was "not as one of the creatures" naturally tended to make Eusebius think that Arius acknowledged a real divinity of the Son, and that appeared to him to be all that was necessary. Meanwhile Alexander in his epistle to Alexander of Constantinople (Theod. H. E. I. 4) had, as Eusebius says, misstated Arius' opinion, or at least had attributed to him the belief that Christ was "made like all other men that have ever been born," whereas Arius expressly disclaims such a belief. Alexander undoubtedly thought that that was the legitimate result to which the other views of Arius must lead; but Eusebius did not think so, and felt himself called upon to remonstrate with Alexander for what seemed to him the latter's unfairness in the matter.