The exact date of our author's birth is unknown to us, but his Ecclesiastical History contains notices which enable us to fix it approximately. In H. E. V.28 he reports that Paul of Samosata attempted to revive again in his day (kath' hemas) the heresy of Artemon. But Paul of Samosata was deposed from the episcopate of Antioch in 272, and was condemned as a heretic at least as early as 268, so that Eusebius must have been born before the latter date, if his words are to be strictly interpreted. Again, according to H. E. III.28, Dionysius was bishop of Alexandria in Eusebius' time (kath' hemas). But Dionysius was bishop from 247 or 248 to 265, and therefore if Eusebius' words are to be interpreted strictly here as in the former case, he must have been born before 265. On the other hand, inasmuch as his death occurred about 340, we cannot throw his birth much earlier than 260. It is true that the references to Paul and to Dionysius do not prove conclusively that Eusebius was alive in their day, for his words may have been used in a loose sense. But in H. E. VII.26, just before proceeding to give an account of Paul of Samosata, he draws the line between his own and the preceding generation, declaring that he is now about to relate the events of his own age (ten kath' hemas). This still further confirms the other indications, and we shall consequently be safe in concluding that Eusebius was born not far from the year 260 a.d. His birthplace cannot be determined with certainty. The fact that he is called "Eusebius the Palestinian" by Marcellus (Euseb. lib. adv. Marcell. I.4), Basil (Lib. ad. Amphil. de Spir. Sancto, c.29), and others, does not prove that he was a Palestinian by birth; for the epithet may be used to indicate merely his place of residence (he was bishop of Cæsarea in Palestine for many years). Moreover, the argument urged by Stein and Lightfoot in support of his Palestinian birth, namely, that it was customary to elect to the episcopate of any church a native of the city in preference to a native of some other place, does not count for much. All that seems to have been demanded was that a man should have been already a member of the particular church over which he was to be made bishop, and even this rule was not universal (see Bingham's Antiquities, II.10, 2 and 3). The fact that he was bishop of Cæsarea therefore would at most warrant us in concluding only that he had made his residence in Cæsarea for some time previous to his election to that office. Nevertheless, although neither of these arguments proves his Palestinian birth, it is very probable that he was a native of that country, or at least of that section. He was acquainted with Syriac as well as with Greek, which circumstance taken in connection with his ignorance of Latin (see below, p.47) points to the region of Syria as his birthplace. Moreover, we learn from his own testimony that he was in Cæsarea while still a youth (Vita Constantini, I.19), and in his epistle to the church of Cæsarea (see below, p.16) he says that he was taught the creed of the Cæsarean church in his childhood (or at least at the beginning of his Christian life: en te katechesei), and that he accepted it at baptism. It would seem therefore that he must have lived while still a child either in Cæsarea itself, or in the neighborhood, where its creed was in use. Although no one therefore (except Theodorus Metochita of the fourteenth century, in his Cap. Miscell.17; Migne, Patr. Lat. CXLIV.949) directly states that Eusebius was a Palestinian by birth, we have every reason to suppose him such.
His parents are entirely unknown. Nicephorus Callistus (H. E. VI.37) reports that his mother was a sister of Pamphilus. He does not mention his authority for this statement, and it is extremely unlikely, in the face of the silence of Eusebius himself and of all other writers, that it is true. It is far more probable that the relationship was later assumed to account for the close intimacy of the two men. Arius, in an epistle addressed to Eusebius of Nicomedia (contained in Theodoret's Hist. Eccles. I.5), calls Eusebius of Cæsarea the latter's brother. It is objected to this that Eusebius of Nicomedia refers to Eusebius of Cæsarea on one occasion as his "master" (tou despotou mou, in his epistle to Paulinus contained in Theodoret's Hist. Eccles. I.6), and that on the other hand Eusebius of Cæsarea calls Eusebius of Nicomedia, "the great Eusebius" (Euseb. lib. adv. Marcell. I.4), both of which expressions seem inconsistent with brotherhood. Lightfoot justly remarks that neither the argument itself nor the objections carry much weight. The term adelphos may well have been used to indicate merely theological or ecclesiastical association, while on the other hand, brotherhood would not exclude the form of expression employed by each in speaking of the other. Of more weight is the fact that neither Eusebius himself nor any historian of that period refers to such a relationship, and also the unlikelihood that two members of one family should bear the same name.
From Eusebius' works we gather that he must have received an extensive education both in secular philosophy and in Biblical and theological science. Although his immense erudition was doubtless the result of wide and varied reading continued throughout life, it is highly probable that he acquired the taste for such reading in his youth. Who his early instructors were we do not know, and therefore cannot estimate the degree of their influence over him. As he was a man, however, who cherished deep admiration for those whom he regarded as great and good men, and as he possessed an unusually acquisitive mind and a pliant disposition, we should naturally suppose that his instructors must have possessed considerable influence over him, and that his methods of study in later years must have been largely molded by their example and precept. We see this exemplified in a remarkable degree in the influence exerted over him by Pamphilus, his dearest friend, and at the same time the preceptor, as it were, of his early manhood. Certainly this great bibliopholist must have done much to strengthen Eusebius' natural taste for omnivorous reading, and the opportunities afforded by his grand library for the cultivation of such a taste were not lost. To the influence of Pamphilus, the devoted admirer and enthusiastic champion of Origen, was doubtless due also in large measure the deep respect which Eusebius showed for that illustrious Father, a respect to which we owe one of the most delightful sections of his Church History, his long account of Origen in the sixth book, and to which in part antiquity was indebted for the elaborate Defense of Origen, composed by Pamphilus and himself, but unfortunately no longer extant. Eusebius certainly owed much to the companionship of that eager student and noble Christian hero, and he always recognized with deep gratitude his indebtedness to him. (Compare the account of Pamphilus given below in Bk. VII. chap.32, §25 sq.) The names of his earlier instructors, who were eminently successful, at least in fostering his thirst for knowledge, are quite unknown to us. His abiding admiration for Plato, whom he always placed at the head of all philosophers (see Stein, p.6), would lead us to think that he received at least a part of his secular training from some ardent Platonist, while his intense interest in apologetics, which lasted throughout his life, and which affected all his works, seems to indicate the peculiar bent of his early Christian education. Trithemius concluded from a passage in his History (VII.32) that Eusebius was a pupil of the learned Dorotheus of Antioch, and Valesius, Lightfoot and others are apparently inclined to accept his conclusion. But, as Stroth remarks (Eusebii Kirchengeschichte, p. xix), all that Eusebius says is that he had heard Dorotheus expound the Scriptures in the church (toutou metrios tas graphas epi tes ekklesias diegoumenou katekousamen), that is, that he had heard him preach. To conclude from this statement that he was a pupil of Dorotheus is certainly quite unwarranted.
Stroth's suggestion that he probably enjoyed the instruction of Meletius for seven years during the persecution rests upon no good ground, for the passage which he relies upon to sustain his opinion (H. E. VII.32.28) says only that Eusebius "observed Meletius well" (katenoesamen) during those seven years.
In Cæsarea Eusebius was at one time a presbyter of the church, as we may gather from his words in the epistle to that church already referred to, where, in speaking of the creed, he says, "As we believed and taught in the presbytery and in the episcopate itself." But the attempt to fix the date of his ordination to that office is quite vain. It is commonly assumed that he became presbyter while Agapius was bishop of Cæsarea, and this is not unlikely, though we possess no proof of it (upon Agapius see below, H. E. VII.32, note 39). In his Vita Constantini, I.19, Eusebius reports that he saw Constantine for the first time in Cæsarea in the train of the Emperor Diocletian. In his Chron. Eusebius reports that Diocletian made an expedition against Egypt, which had risen in rebellion in the year 296 a.d., and Theophanes, in his Chron., says that Constantine accompanied him. It is probable therefore that it was at this time that Eusebius first saw Constantine in Cæsarea, when he was either on his way to Egypt, or on his way back (see Tillemont's Hist. des Emp., IV. p.34).
During these years of quiet, before the great persecution of Diocletian, which broke out in 303 a.d., Eusebius' life must have been a very pleasant one. Pamphilus' house seems to have been a sort of rendezvous for Christian scholars, perhaps a regular divinity school; for we learn from Eusebius' Martyrs in Palestine (Cureton's edition, pp.13 and 14) that he and a number of others, including the martyr Apphianus, were living together in one house at the time of the persecution, and that the latter was instructed in the Scriptures by Pamphilus and acquired from him virtuous habits and conduct. The great library of Pamphilus would make his house a natural center for theological study, and the immense amount of work which was done by him, or under his direction, in the reproduction of copies of the Holy Scriptures, of Origen's works (see Jerome's de vir. ill.75 and 81, and contra Ruf. I.9), and in other literary employments of the same kind, makes it probable that he had gathered about him a large circle of friends and students who assisted him in his labors and profited by his counsel and instruction. Amidst these associations Eusebius passed his early manhood, and the intellectual stimulus thus given him doubtless had much to do with his future career. He was above all a literary man, and remained such to the end of his life. The pleasant companionships of these days, and the mutual interest and sympathy which must have bound those fellow-students and fellow-disciples of Pamphilus very close together, perhaps had much to do with that broad-minded spirit of sympathy and tolerance which so characterized Eusebius in later years. He was always as far as possible from the character of a recluse. He seems ever to have been bound by very strong ties to the world itself and to his fellow-men. Had his earlier days been filled with trials and hardships, with the bitterness of disappointed hopes and unfulfilled ambitions, with harsh experiences of others' selfishness and treachery, who shall say that the whole course of his life might not have been changed, and his writings have exhibited an entirely different spirit from that which is now one of their greatest charms? Certainly he had during these early years in Cæsarea large opportunities for cultivating that natural trait of admiration for other men, which was often so strong as to blind him even to their faults, and that natural kindness which led him to see good wherever it existed in his Christian brethren. At the same time these associations must have had considerable influence in fostering the apologetic temper. The pursuits of the little circle were apparently exclusively Christian, and in that day when Christianity stood always on its defense, it would naturally become to them a sacred duty to contribute to that defense and to employ all their energies in the task. It has been remarked that the apologetic temper is very noticeable in Eusebius' writings. It is more than that; we may say indeed in general terms that everything he wrote was an apology for the faith. His History was written avowedly with an apologetic purpose, his Chronicle was composed with the same end in view. Even when pronouncing a eulogy upon a deceased emperor he seized every possible opportunity to draw from that emperor's career, and from the circumstances of his reign, arguments for the truth and grandeur of the Christian religion. His natural temper of mind and his early training may have had much to do with this habit of thought, but certainly those years with Pamphilus and his friends in Cæsarea must have emphasized and developed it.
Another characteristic which Pamphilus and the circle that surrounded him doubtless did something to develop in our author was a certain superiority to the trammels of mere traditionalism, or we might perhaps better say that they in some measure checked the opposite tendency of slavishness to the traditional which seems to have been natural to him. Pamphilus' deep reverence for Origen proclaims him at once superior to that kind of narrow conservatism which led many men as learned and doubtless as conscientious as himself to pass severe and unconditional condemnation upon Origen and all his teaching. The effect of championing his cause must have fostered in this little circle, which was a very hotbed of Origenism, a contempt for the narrow and unfair judgments of mere traditionalists, and must have led them to seek in some degree the truth solely for its own sake, and to become in a measure careless of its relation to the views of any school or church. It could hardly be otherwise than that the free and fearless spirit of Origen should leave its impress through his writings upon a circle of followers so devoted to him as were these Cæsarean students. Upon the impressionable Eusebius these influences necessarily operated. And yet he brought to them no keen speculative powers, no deep originality such as Origen himself possessed. His was essentially an acquisitive, not a productive mind, and hence it was out of the question that he should become a second Origen. It was quite certain that Origen's influence over him would weaken somewhat his confidence in the traditional as such, -- a confidence which is naturally great in such minds as his, -- but at the same time would do little to lessen the real power of the past over him. He continued to get his truth from others, from the great men of the past with whom he had lived and upon whose thought he had feasted. All that he believed he had drawn from them; he produced nothing new for himself, and his creed was a traditional creed. And yet he had at the same time imbibed from his surroundings the habit of questioning and even criticising the past, and, in spite of his abiding respect for it, had learned to feel that the voice of the many is not always the voice of truth, and that the widely and anciently accepted is sometimes to be corrected by the clearer sight of a single man. Though he therefore depended for all he believed so completely upon the past, his associations had helped to free him from a slavish adherence to all that a particular school had accepted, and had made him in some small measure an eclectic in his relations to doctrines and opinions of earlier generations. A notable instance of this eclecticism on his part is seen in his treatment of the Apocalypse of John. He felt the force of an almost universal tradition in favor of its apostolic origin, and yet in the face of that he could listen to the doubts of Dionysius, and could be led by his example, in a case where his own dissatisfaction with the book acted as an incentive, almost, if not quite, to reject it and to ascribe it to another John. Instances of a similar mode of conduct on his part are quite numerous. While he is always a staunch apologist for Christianity, he seldom, if ever, degenerates into a mere partisan of any particular school or sect.
One thing in fact which is particularly noticeable in Eusebius' works is the comparatively small amount of time and space which he devotes to heretics. With his wide and varied learning and his extensive acquaintance with the past, he had opportunities for successful heresy hunting such as few possessed, and yet he never was a heresy hunter in any sense. This is surprising when we remember what a fascination this employment had for so many scholars of his own age, and when we realize that his historical tastes and talents would seem to mark him out as just the man for that kind of work. May it not be that the lofty spirit of Origen, animating that Cæsarean school, had something to do with the happy fact that he became an apologist instead of a mere polemic, that he chose the honorable task of writing a history of the Church instead of anticipating Epiphanius' Panarium?
It was not that he was not alive to the evils of heresy. He shared with nearly all good church-men of his age an intense aversion for those who, as he believed, had corrupted the true Gospel of Christ. Like them he ascribed heresy to the agency of the evil one, and was no more able than they to see any good in a man whom he looked upon as a real heretic, or to do justice in any degree to the error which he taught. His condemnations of heretics in his Church History are most severe. Language is hardly strong enough to express his aversion for them. And yet, although he is thus most thoroughly the child of his age, the difference between him and most of his contemporaries is very apparent. He mentions these heretics only to dismiss them with disapproval or condemnation. He seldom, if ever, discusses and refutes their views. His interests lie evidently in other directions; he is concerned with higher things. A still more strongly marked difference between himself and many churchmen of his age lies in his large liberality towards those of his own day who differed with him in minor points of faith, and his comparative indifference to the divergence of views between the various parties in the Church. In all this we believe is to be seen not simply the inherent nature of the man, but that nature as trained in the school of Pamphilus, the disciple of Origen.