Eusebius

Eusebius of Caesarea (/juːˈsiːbiəs/; Greek: Εὐσέβιος τῆς Καισαρείας, Eusébios tés Kaisareías; AD 260/265 – 339/340), also known as Eusebius Pamphili (from the Greek: Εὐσέβιος τοῦ Παμϕίλου), was a historian of Christianity, exegete, and Christian polemicist. He became the bishop of Caesarea Maritima about 314 AD. Together with Pamphilus, he was a scholar of the Biblical canon and is regarded as an extremely learned Christian of his time. He wrote Demonstrations of the Gospel, Preparations for the Gospel, and On Discrepancies between the Gospels, studies of the Biblical text. As "Father of Church History" (not to be confused with the title of Church Father), he produced the Ecclesiastical History, On the Life of Pamphilus, the Chronicle and On the Martyrs. He also produced a biographical work on the first Christian Emperor, Constantine the Great, who ruled between 306 and 337 AD.

During the Council of Antioch, which was convened in 325 and held shortly before the First Ecumenical Council in the Bythnian city of Nicaea, he was excommunicated for subscribing to the heresy of Arius.

The debate raged over whether Christ is of the "same substance" (homoousion), or "similar substance" (homoiousian)to the Father. This was no exercise in semantics, for if Christ is of the 'same substance', or 'essence' as the Father, then this testifies to His divinity. On the other hand, if Christ is of 'similar substance' to the Father – as Arius believed, then this testifies that Christ had a beginning in time, is therefore subordinate to the Father and is little more than a created being. While the Greek fathers of the church applied the Aristotelian term ousiato the divine essence of God, it translated into Latin as essentia, orsubstantia(substance). The Greek term homoousios was consequently translated into Latin as coessentialis or consubstantialis, which in English translates as coessential and consubstantial. Thus the test for heresy at Nicaea was based upon what eventually became the orthodox confession that the Father and Son areconsubstantial (homoousios); which is to say that they are of identical substance, or, as the Greeks would say, essence with each other –which then professed the emerging Trinitarian faith, as the object of Nicaea was to preserve the divinity of Christ, by stating that the divinity of the Son is consubstantial with the Father.

As the dogma of the Trinity came to be refined in the succeeding centuries, this led to ongoing problems associated with Arius' original accusation of modalism, which he had leveled at Alexander; for prominent 19th century church historian Adolf von Harnack says of Latin theologian Augustine (354–430), celebrated "Doctor" of the Catholic Church, and who has been called the most significant Christian theologian “since New Testament times,"that"Augustine only gets beyond modalism by the mere assertion that he does not wish to be a Modalist.'" Drawing upon previous theologians, such as Tertullian and Ambrose of Milan (who baptized him in 387), Augustine was instrumental in describing the Filioqe (the procession of the Holy Spirit) in De Trinitate(the Trinity), which saw some Latin churches begin to adopt the term in the 6th century, which began a schism between the Latin and Greek churches.

The main contenders for the faith at Nicaea were Athanasius of Alexandria, and Arius, who vehemently opposed each other. Drawing from" ... the language and thoughts of Hellenistic [Greek] metaphysics", and " ... employing the terms substance in the Nicene Creed and consubsantial in the Chalcedonian Creed, the church fathers were tapping into Neoplatonism." Arius was no exception, for according to Baptist theolgian Roger Olssen:

"In the deep background of the clash between Arius and Alexander over the nature of the Logos lay Greek philosophy. It is something both had in common, even if they interpreted and applied it differently. Both sides of the conflict simply assumed that divinity is ontologically perfect in such a way that any change at all is impossible for and improper to attribute to it. Thus God, being divine and therefore absolutely perfect, cannot experience change because change is always to change either for the better or for the worse, and in either case God would not be God if he could change. Absolute static perfection – including apatheia, or impassibility (passionlessness)–is the nature of God according to Greek thought, and nearly all Christian theologians came to agree with this . . . God's immutability and impassibility, then, became chief attributes of God in Christian theology, and Arius and his followers exploited the argument that if Jesus Christ is the incarnation of the Logos and if the Logos is divine in the same sense that God the Father is divine, then God's nature would be changed by the human life of Jesus in time and God would have suffered with him. But that is impossible. Therefore the Logos who became incarnate in Jesus Christ must not be fully divine but rather must [according to Arius] be a great and exalted creature."

The first Christian Emperor, Constantine the Great, had converted to Christianity directly after the Battle of the Milvian Bridge in 312 A.D, after reputedly seeing a flaming cross in the sky which was emblazoned with the words "In Hoc Signo Vinces"; which translates to "In this Sign Conquer." According to Eusebius, in the evening before the battle Constantine went to sleep unsure what this sign could mean, but then had a dream in which Christ appeared to him, and commanded him to make a likeness of the sign which he had seen in the heavens, as it would protect him in all future engagements with his enemies. The next day, Constantine promised the Christian god that if his army were to win the battle, he would adopt the Christian religion - which is precisely what happened. In the June, 2002 edition of the 'Church History' journal, Pier Beatrice reports that Eusebius testified that the word homoousios (consubstantial) " ... was inserted in the Nicene Creed solely by the personal order of Constantine."

"According to Eusebius of Caesarea, the wordhomoousios was inserted in the Nicene Creed solely by the personal order of Constantine.But this statement is highly problematic. It is very difficult to explain the seeming paradoxical fact that this word, along with the explanation given by Constantine, was accepted by the "Arian" Eusebius, wheras it has left no traces at all in the works of his opponents, the leaders of the anti-Arian party such as Alexander of Alexandria, Ossius of Cordova, Marcellus of Ancyra, and Eustathius of Antioch, who are usually considered Constantine's theological advisers and the strongest supporters of the council. Neither before nor during Constantine's time is there any evidence of a normal, well-established Christian use of the termhomoousios in its strictly Trinitarian meaning. Having once excluded any relationship of the Nicene homoousios with the Christian tradition, it becomes legitimate to propose a new explanation, based on an analysis of two pagan documents which have so far never been taken into account. The main theses of this paper is thathomoousios came straight from Constantine's Hermetic background. As can be clearly seen in the Poimandres, and even more clearly in an inscription mentioned exclusively in the Theosophia, in the theological language of Egyptian paganism the word homoousios meant that the Nous-Father and the Logos-Son, who are two distinct beings, share the same perfection of the divine nature."

Although Eusebius' works are regarded as giving insight into the history of the early church, he was not without prejudice, especially in regard to the Jews, for while "Eusebius indeed blames the Jews for the crucifxion of Jesus, but he nevertheless also states that forgiveness can be granted even for this sin and that the Jews can receive salvation." Nor can his works be trusted to be from subjectivism, for some scholars believe that "Eusebius is a notoriously unreliable historian, and so anything he reports should be critically scrutinized." This is especially true of his 'Life of Constantine', which he wrote as an eulogy shortly after the emperor's death in 337 A.D, and which is "Often maligned for perceived factual errors, deemed by some so hopelessly flawed that it cannot be the work of Eusebius at all."Yet others see him as a "Constantinian flunky," for as a trusted adviser to Constantine, it was politically expedient for him to present Constantine in the best light as possible. Never recognized as a saint, the likely reason for this is that traditional sources view Arius finding support " ... from Eusebius of Nicomedia, and our Eusebius, who by that time was bishop of Caesarea."

Little is known about the life of Eusebius. His successor at the See of Caesarea, Acacius, wrote a Life of Eusebius, a work that has since been lost. Eusebius' own surviving works probably only represent a small portion of his total output.Beyond notices in his extant writings, the major sources are the 5th-century ecclesiastical historians Socrates, Sozomen, and Theodoret, and the 4th-century Christian author Jerome. There are assorted notices of his activities in the writings of his contemporaries Athanasius, Arius, Eusebius of Nicomedia, and Alexander of Alexandria. Eusebius' pupil, Eusebius of Emesa, provides some incidental information.

In his Ecclesiastical History, Eusebius writes of Dionysius of Alexandria as his contemporary. If this is true, Eusebius' birth must have been before Dionysius' death in autumn 264; most modern scholars date the birth to some point in the five years between 260 and 265. He was presumably born in the town in which he lived for most of his adult life, Caesarea Maritima. He was baptized and instructed in the city, and lived in Syria Palaestina in 296, when Diocletian's army passed through the region (in the Life of Constantine, Eusebius recalls seeing Constantine traveling with the army). Eusebius was made presbyter by Agapius of Caesarea. Some, like theologian and ecclesiastical historian John Henry Newman, understand Eusebius' statement that he had heard Dorotheus of Tyre "expound the Scriptures wisely in the Church" to indicate that Eusebius was Dorotheus' pupil while the priest was resident in Antioch; others, like the scholar D. S. Wallace-Hadrill, deem the phrase too ambiguous to support the contention.

By the 3rd century, Caesarea had a population of about 100,000. It had been a pagan city since Pompey had given control of the city to the gentiles during his command of the eastern provinces in the 60s BC. The gentiles retained control of the city for the three centuries to follow, despite Jewish petitions for joint governorship. Gentile government was strengthened by the city's refoundation under Herod the Great (r. 37–4 BC), when it had taken on the name of Augustus Caesar. In addition to the gentile settlers, Caesarea had large Jewish and Samaritan minorities. Eusebius was probably born into the Christian contingent of the city. Caesarea's Christian community presumably had a history reaching back to apostolic times, but it is a common claim that no bishops are attested for the town before about 190, even though the Apostolic Constitutions 7.46 states that Zacchaeus was the first bishop.

Through the activities of the theologian Origen (185/6–254) and the school of his follower Pamphilus (later 3rd century – 309), Caesarea became a center of Christian learning. Origen was largely responsible for the collection of usage information, or which churches were using which gospels, regarding the texts which became the New Testament. The information used to create the late-fourth-century Easter Letter, which declared accepted Christian writings, was probably based on the Ecclesiastical History [HE] of Eusebius of Caesarea, wherein he uses the information passed on to him by Origen to create both his list at HE 3:25 and Origen's list at HE 6:25. Eusebius got his information about what texts were accepted by the third-century churches throughout the known world, a great deal of which Origen knew of firsthand from his extensive travels, from the library and writings of Origen.

On his deathbed, Origen had made a bequest of his private library to the Christian community in the city. Together with the books of his patron Ambrosius, Origen's library (including the original manuscripts of his works) formed the core of the collection that Pamphilus established. Pamphilus also managed a school that was similar to (or perhaps a re-establishment of) that of Origen. Pamphilus was compared to Demetrius of Phalerum and Pisistratus, for he had gathered Bibles "from all parts of the world". Like his model Origen, Pamphilus maintained close contact with his students. Eusebius, in his history of the persecutions, alludes to the fact that many of the Caesarean martyrs lived together, presumably under Pamphilus.

Soon after Pamphilus settled in Caesarea (ca. 280s), he began teaching Eusebius, who was then somewhere between twenty and twenty-five. Because of his close relationship with his schoolmaster, Eusebius was sometimes called Eusebius Pamphili: "Eusebius, son of Pamphilus". The name may also indicate that Eusebius was made Pamphilus' heir. Pamphilus gave Eusebius a strong admiration for the thought of Origen. Neither Pamphilus nor Eusebius knew Origen personally; Pamphilus probably picked up Origenist ideas during his studies under Pierius (nicknamed "Origen Junior") in Alexandria. In Caesarea, Origenist thought was continued in the generation after his death by Theotecnus, bishop of the city for much of the late 3rd century and an alumnus of Origen's school.

Eusebius' Preparation for the Gospel bears witness to the literary tastes of Origen: Eusebius quotes no comedy, tragedy, or lyric poetry, but makes reference to all the works of Plato and to an extensive range of later philosophic works, largely from Middle Platonists from Philo to the late 2nd century. Whatever its secular contents, the primary aim of Origen and Pamphilus' school was to promote sacred learning. The library's biblical and theological contents were more impressive: Origen's Hexapla and Tetrapla; a copy of the original Aramaic version of the Gospel of Matthew; and many of Origen's own writings. Marginal comments in extant manuscripts note that Pamphilus and his friends and pupils, including Eusebius, corrected and revised much of the biblical text in their library. Their efforts made the hexaplaric Septuagint text increasingly popular in Syria and Palestine. Soon after joining Pamphilus' school, Eusebius started helping his master expand the library's collections and broaden access to its resources. At about this time Eusebius compiled a Collection of Ancient Martyrdoms, presumably for use as a general reference tool.

In the 290s, Eusebius began work on his magnum opus, the Ecclesiastical History, a narrative history of the Church and Christian community from the Apostolic Age to Eusebius' own time. At about the same time, he worked on his Chronicle, a universal calendar of events from the Creation to, again, Eusebius' own time. He completed the first editions of the Ecclesiastical History and Chronicle before 300.

Eusebius succeeded Agapius as Bishop of Caesarea soon after 313 and was called on by Arius who had been excommunicated by his bishop Alexander of Alexandria. An episcopal council in Caesarea pronounced Arius blameless. Eusebius, a learned man and famous author, enjoyed the favour of the Emperor Constantine. Because of this he was called upon to present the creed of his own church to the 318 attendees of the Council of Nicaea in 325." However, the anti-Arian creed from Palestine prevailed becoming the basis for the Nicene Creed.

The theological views of Arius, that taught the subordination of the Son to the Father, continued to be a problem. Eustathius of Antioch strongly opposed the growing influence of Origen's theology as the root of Arianism. Eusebius, an admirer of Origen, was reproached by Eustathius for deviating from the Nicene faith. Eusebius prevailed and Eustathius was deposed at a synod in Antioch.

However, Athanasius of Alexandria became a more powerful opponent and in 334, he was summoned before a synod in Caesarea (which he refused to attend). In the following year, he was again summoned before a synod in Tyre at which Eusebius of Caesarea presided. Athanasius, foreseeing the result, went to Constantinople to bring his cause before the Emperor. Constantine called the bishops to his court, among them Eusebius. Athanasius was condemned and exiled at the end of 335. Eusebius remained in the Emperor's favour throughout this time and more than once was exonerated with the explicit approval of the Emperor Constantine. After the Emperor's death (c.337), Eusebius wrote the Life of Constantine, an important historical work because of eye witness accounts and the use of primary sources. Eusebius died c.339.

Much like his birth, the exact date of Eusebius' death is unknown. However, there is primary text evidence from a council held in Antioch that by the year 341, his successor Acacius had already filled the seat as Bishop. Socrates and Sozomen write about Eusebius' death, and place it just before Constantine's son Constantine II died, which was in early 340. They also say that it was after the second banishment of Athanasius, which began in mid 339. This means that his death occurred some time between the second half of 339 and early 340.

Armenian translation of Chronicon. 13th century manuscript

Of the extensive literary activity of Eusebius, a relatively large portion has been preserved. Although posterity suspected him of Arianism, Eusebius had made himself indispensable by his method of authorship; his comprehensive and careful excerpts from original sources saved his successors the painstaking labor of original research. Hence, much has been preserved, quoted by Eusebius, which otherwise would have been lost.

The literary productions of Eusebius reflect on the whole the course of his life. At first, he occupied himself with works on Biblical criticism under the influence of Pamphilus and probably of Dorotheus of Tyre of the School of Antioch. Afterward, the persecutions under Diocletian and Galerius directed his attention to the martyrs of his own time and the past, and this led him to the history of the whole Church and finally to the history of the world, which, to him, was only a preparation for ecclesiastical history.

Then followed the time of the Arian controversies, and dogmatic questions came into the foreground. Christianity at last found recognition by the State; and this brought new problems—apologies of a different sort had to be prepared. Lastly, Eusebius wrote eulogies in praise of Constantine. To all this activity must be added numerous writings of a miscellaneous nature, addresses, letters, and the like, and exegetical works that extended over the whole of his life and that include both commentaries and treatises on Biblical archaeology.

Onomasticon

Biblical text criticism

Eusebius's canon tables were often included in Early Medieval Gospel books

Pamphilus and Eusebius occupied themselves with the textual criticism of the Septuagint text of the Old Testament and especially of the New Testament. An edition of the Septuagint seems to have been already prepared by Origen, which, according to Jerome, was revised and circulated by Eusebius and Pamphilus. For an easier survey of the material of the four Evangelists, Eusebius divided his edition of the New Testament into paragraphs and provided it with a synoptical table so that it might be easier to find the pericopes that belong together. These canon tables or "Eusebian canons" remained in use throughout the Middle Ages, and illuminated manuscript versions are important for the study of early medieval art, as they are the most elaborately decorated pages of many Gospel books. Eusebius detailed in Epistula ad Carpianum how to use his canons.

Chronicle

The Chronicle (Παντοδαπὴ Ἱστορία (Pantodape historia)) is divided into two parts. The first part, the Chronography (Χρονογραφία (Chronographia)), gives an epitome of universal history from the sources, arranged according to nations. The second part, the Canons (Χρονικοὶ Κανόνες (Chronikoi kanones)), furnishes a synchronism of the historical material in parallel columns, the equivalent of a parallel timeline.

The work as a whole has been lost in the original Greek, but it may be reconstructed from later chronographists of the Byzantine school who made excerpts from the work, especially George Syncellus. The tables of the second part have been completely preserved in a Latin translation by Jerome, and both parts are still extant in an Armenian translation. The loss of the Greek originals has given the Armenian translation a special importance; thus, the first part of Eusebius' Chronicle, of which only a few fragments exist in the Greek, has been preserved entirely in Armenian, though with lacunae. The Chronicle as preserved extends to the year 325.

Church History

In his Church History or Ecclesiastical History, Eusebius wrote the first surviving history of the Christian Church as a chronologically-ordered account, based on earlier sources, complete from the period of the Apostles to his own epoch. The time scheme correlated the history with the reigns of the Roman Emperors, and the scope was broad. Included were the bishops and other teachers of the Church, Christian relations with the Jews and those deemed heretical, and the Christian martyrs through 324. Although its accuracy and biases have been questioned, it remains an important source on the early church due to Eusebius's access to materials now lost.

Life of Constantine

Eusebius' Life of Constantine (Vita Constantini) is a eulogy or panegyric, and therefore its style and selection of facts are affected by its purpose, rendering it inadequate as a continuation of the Church History. As the historian Socrates Scholasticus said, at the opening of his history which was designed as a continuation of Eusebius, "Also in writing the life of Constantine, this same author has but slightly treated of matters regarding Arius, being more intent on the rhetorical finish of his composition and the praises of the emperor, than on an accurate statement of facts." The work was unfinished at Eusebius' death. Some scholars have questioned the Eusebian authorship of this work.

Minor historical works

Before he compiled his church history, Eusebius edited a collection of martyrdoms of the earlier period and a biography of Pamphilus. The martyrology has not survived as a whole, but it has been preserved almost completely in parts. It contained:

• an epistle of the congregation of Smyrna concerning the martyrdom of Polycarp;
• the martyrdom of Pionius;
• the martyrdoms of Carpus, Papylus, and Agathonike;
• the martyrdoms in the congregations of Vienne and Lyon;
• the martyrdom of Apollonius.

Of the life of Pamphilus, only a fragment survives. A work on the martyrs of Palestine in the time of Diocletian was composed after 311; numerous fragments are scattered in legendaries which have yet to be collected. The life of Constantine was compiled after the death of the emperor and the election of his sons as Augusti (337). It is more a rhetorical eulogy on the emperor than a history but is of great value on account of numerous documents incorporated in it.

Apologetic and dogmatic works

To the class of apologetic and dogmatic works belong:

• The Apology for Origen, the first five books of which, according to the definite statement of Photius, were written by Pamphilus in prison, with the assistance of Eusebius. Eusebius added the sixth book after the death of Pamphilus. We possess only a Latin translation of the first book, made by Rufinus;
• A treatise against Hierocles (a Roman governor), in which Eusebius combated the former's glorification of Apollonius of Tyana in a work entitled A Truth-loving Discourse (Greek: Philalethes logos); in spite of manuscript attribution to Eusebius, however, it has been argued (by Thomas Hagg and more recently, Aaron Johnson that this treatise "Against Hierocles" was written by someone other than Eusebius of Caesarea.
• Praeparatio evangelica (Preparation for the Gospel), commonly known by its Latin title, which attempts to prove the excellence of Christianity over every pagan religion and philosophy. The Praeparatio consists of fifteen books which have been completely preserved. Eusebius considered it an introduction to Christianity for pagans. But its value for many later readers is more because Eusebius studded this work with so many lively fragments from historians and philosophers which are nowhere else preserved. Here alone is preserved Pyrrho's translation of the Buddhist Three marks of existence upon which Pyrrho based Pyrrhonism. Here alone is a summary of the writings of the Phoenician priest Sanchuniathon of which the accuracy has been shown by the mythological accounts found on the Ugaritic tables. Here alone is the account from Diodorus Siculus's sixth book of Euhemerus' wondrous voyage to the island of Panchaea where Euhemerus purports to have found his true history of the gods. And here almost alone is preserved writings of the neo-Platonist philosopher Atticus along with so much else.
• Demonstratio evangelica (Proof of the Gospel) is closely connected to the Praeparatio and comprised originally twenty books of which ten have been completely preserved as well as a fragment of the fifteenth. Here Eusebius treats of the person of Jesus Christ. The work was probably finished before 311;
• Another work which originated in the time of the persecution, entitled Prophetic Extracts (Eclogae propheticae). It discusses in four books the Messianic texts of Scripture. The work is merely the surviving portion (books 6–9) of the General elementary introduction to the Christian faith, now lost.The fragments given as the Commentary on Luke in the PG have been claimed to derive from the missing tenth book of the General Elementary Introduction see D. S. Wallace-Hadrill); however, Aaron Johnson has argued that they cannot be associated with this work.

• The treatise On Divine Manifestation or On the Theophania (Peri theophaneias), of unknown date. It treats of the incarnation of the Divine Logos, and its contents are in many cases identical with the Demonstratio evangelica. Only fragments are preserved in Greek, but a complete Syriac translation of the Theophania survives in an early 5th-century manuscript. Samuel Lee, the editor (1842) and translator (1843) of the Syriac Theophania thought that the work must have been written "after the general peace restored to the Church by Constantine, and before either the 'Praeparatio,' or the 'Demonstratio Evangelica,' was written . . . it appears probable . . . therefore, that this was one of the first productions of Eusebius, if not the first after the persecutions ceased." Hugo Gressmann, noting in 1904 that the Demonstratio seems to be mentioned at IV. 37 and V. 1, and that II. 14 seems to mention the extant practice of temple prostitution at Hieropolis in Phoenica, concluded that the Theophania was probably written shortly after 324. Others have suggested a date as late as 337.
• A polemical treatise against Marcellus of Ancyra, the Against Marcellus, dating from about 337;
• A supplement to the last-named work, also against Marcellus, entitled Ecclesiastical Theology, in which he defended the Nicene doctrine of the Logos against the party of Athanasius.

A number of writings, belonging in this category, have been entirely lost.

Exegetical and miscellaneous works

All of the exegetical works of Eusebius have suffered damage in transmission. The majority of them are known to us only from long portions quoted in Byzantine catena-commentaries. However these portions are very extensive. Extant are:

• An enormous Commentary on the Psalms.
• A commentary on Isaiah, discovered more or less complete in a manuscript in Florence early in the 20th century and published 50 years later.
• Small fragments of commentaries on Romans and 1 Corinthians.

Eusebius also wrote a work Quaestiones ad Stephanum et Marinum, "On the Differences of the Gospels" (including solutions). This was written for the purpose of harmonizing the contradictions in the reports of the different Evangelists. This work was recently (2011) translated into the English language by David J. Miller and Adam C. McCollum (edited by Roger Pearse) and was published under the name "Eusebius of Caesarea: Gospel Problems and Solutions." The original work was also translated into Syriac, and lengthy quotations exist in a catena in that language, and also in Coptic and Arabic catenas.

Eusebius also wrote treatises on Biblical archaeology:

• A work on the Greek equivalents of Hebrew Gentilic nouns;
• A description of old Judea with an account of the loss of the ten tribes;
• A plan of Jerusalem and the Temple of Solomon.

These three treatises have been lost.

The addresses and sermons of Eusebius are mostly lost, but some have been preserved, e.g., a sermon on the consecration of the church in Tyre and an address on the thirtieth anniversary of the reign of Constantine (336).

Most of Eusebius' letters are lost. His letters to Carpianus and Flacillus exist complete. Fragments of a letter to the empress Constantia also exists.

Eusebius is fairly unusual in his preterist, or fulfilled eschatological view.Saying "The Holy Scriptures foretell that there will be unmistakable signs of the Coming of Christ. Now there were among the Hebrews three outstanding offices of dignity, which made the nation famous, firstly the kingship, secondly that of prophet, and lastly the high priesthood. The prophecies said that the abolition and complete destruction of all these three together would be the sign of the presence of the Christ. And that the proofs that the times had come, would lie in the ceasing of the Mosaic worship, the desolation of Jerusalem and its Temple, and the subjection of the whole Jewish race to its enemies...The holy oracles foretold that all these changes, which had not been made in the days of the prophets of old, would take place at the coming of the Christ, which I will presently shew to have been fulfilled as never before in accordance with the predictions." (Demonstratio Evangelica VIII)

From a dogmatic point of view, Eusebius stands entirely upon the shoulders of Origen. Like Origen, he started from the fundamental thought of the absolute sovereignty (monarchia) of God. God is the cause of all beings. But he is not merely a cause; in him everything good is included, from him all life originates, and he is the source of all virtue. God sent Christ into the world that it may partake of the blessings included in the essence of God. Christ is God and is a ray of the eternal light; but the figure of the ray is so limited by Eusebius that he expressly distinguishes the Son as distinct from Father as a ray is also distinct from its source the sun.

Eusebius was intent upon emphasizing the difference of the persons of the Trinity and maintaining the subordination of the Son (Logos, or Word) to God. The Logos, the Son (Jesus) is an hypostasis of God the Father whose generation, for Eusebius, took place before time. The Logos acts as the organ or instrument of God, the creator of life, the principle of every revelation of God, who in his absoluteness and transcendence is enthroned above and isolated from all the world. Eusebius, with most of the Christian tradition, assumed God was immutable. Therefore, to Eusebius's mind, the Logos must possess divinity by participation (and not originally like the Father), so that he can change, unlike God the Father. Thus he assumed a human body without altering the immutable divine Father. Eusebius never calls Jesus o theós, but theós because in all contrary attempts he suspected either polytheism (three distinct gods) or Sabellianism (three modes of one divine person).

Likewise, Eusebius described the relation of the Holy Spirit within the Trinity to that of the Son to the Father. No point of this doctrine is original with Eusebius, all is traceable to his teacher Origen. The lack of originality in his thinking shows itself in the fact that he never presented his thoughts in a system. After nearly being excommunicated due to charges of heresy by Alexander of Alexandria, Eusebius submitted and agreed to the Nicene Creed at the First Council of Nicea in 325.

Eusebius held that men were sinners by their own free choice and not by the necessity of their natures. Eusebius said, "The Creator of all things has impressed a natural law upon the soul of every man, as an assistant and ally in his conduct, pointing out to him the right way by this law; but, by the free liberty with which he is endowed, making the choice of what is best worthy of praise and acceptance, because he has acted rightly, not by force, but from his own free-will, when he had it in his power to act otherwise, As, again, making him who chooses what is worst, deserving of blame and punishment, as having by his own motion neglected the natural law, and becoming the origin and fountain of wickedness, and misusing himself, not from any extraneous necessity, but from free will and judgment. The fault is in him who chooses, not in God. For God has not made nature or the substance of the soul bad; for he who is good can make nothing but what is good. Everything is good which is according to nature. Every rational soul has naturally a good free-will, formed for the choice of what is good. But when a man acts wrongly, nature is not to be blamed; for what is wrong, takes place not according to nature, but contrary to nature, it being the work of choice, and not of nature".

By the time of the Byzantine Iconoclasm several centuries later, Eusebius had unfairly gained the reputation of having been an Arian, and was roundly condemned as such by Patriarch Nikephoros I of Constantinople.A letter Eusebius is supposed to have written to Constantine's daughter Constantia, refusing to fulfill her request for images of Christ, was quoted in the decrees (now lost) of the Iconoclast Council of Hieria in 754, and later quoted in part in the rebuttal of the Hieria decrees in the Second Council of Nicaea of 787, now the only source from which some of the text is known.The authenticity, or authorship of the letter remain uncertain.

• Edward Gibbon openly distrusted the writings of Eusebius concerning the number of martyrs, by noting a passage in the shorter text of the Martyrs of Palestine attached to the Ecclesiastical History (Book 8, Chapter 2) in which Eusebius introduces his description of the martyrs of the Great Persecution under Diocletian with: "Wherefore we have decided to relate nothing concerning them except the things in which we can vindicate the Divine judgment. [...] We shall introduce into this history in general only those events which may be useful first to ourselves and afterwards to posterity." In the longer text of the same work, chapter 12, Eusebius states: "I think it best to pass by all the other events which occurred in the meantime: such as [...] the lust of power on the part of many, the disorderly and unlawful ordinations, and the schisms among the confessors themselves; also the novelties which were zealously devised against the remnants of the Church by the new and factious members, who added innovation after innovation and forced them in unsparingly among the calamities of the persecution, heaping misfortune upon misfortune. I judge it more suitable to shun and avoid the account of these things, as I said at the beginning."
• When his own honesty was challenged by his contemporaries, Gibbon appealed to a chapter heading in Eusebius' Praeparatio evangelica (Book XII, Chapter 31) in which Eusebius discussed "That it will be necessary sometimes to use falsehood as a remedy for the benefit of those who require such a mode of treatment."
• Although Gibbon refers to Eusebius as the 'gravest' of the ecclesiastical historians, he also suggests that Eusebius was more concerned with the passing political concerns of his time than his duty as a reliable historian.
• Jacob Burckhardt (19th century cultural historian) dismissed Eusebius as "the first thoroughly dishonest historian of antiquity".
• Other critics of Eusebius' work cite the panegyrical tone of the Vita, plus the omission of internal Christian conflicts in the Canones, as reasons to interpret his writing with caution.

Alternate views have suggested that Gibbon's dismissal of Eusebius is inappropriate:

• With reference to Gibbon's comments, Joseph Barber Lightfoot (late 19th century theologian and former Bishop of Durham) pointed out that Eusebius' statements indicate his honesty in stating what he was not going to discuss, and also his limitations as a historian in not including such material. He also discusses the question of accuracy. "The manner in which Eusebius deals with his very numerous quotations elsewhere, where we can test his honesty, is a sufficient vindication against this unjust charge." Lightfoot also notes that Eusebius cannot always be relied on: "A far more serious drawback to his value as a historian is the loose and uncritical spirit in which he sometimes deals with his materials. This shows itself in diverse ways. He is not always to be trusted in his discrimination of genuine and spurious documents."
• Averil Cameron (professor at King's College and Oxford) and Stuart Hall (historian and theologian), in their recent translation of the Life of Constantine, point out that writers such as Burckhardt found it necessary to attack Eusebius in order to undermine the ideological legitimacy of the Habsburg empire, which based itself on the idea of Christian empire derived from Constantine, and that the most controversial letter in the Life has since been found among the papyri of Egypt.
• In Church History (Vol. 59, 1990), Michael J. Hollerich (assistant professor at the Jesuit Santa Clara University, California) replies to Burckhardt's criticism of Eusebius, that "Eusebius has been an inviting target for students of the Constantinian era. At one time or another they have characterized him as a political propagandist, a good courtier, the shrewd and worldly adviser of the Emperor Constantine, the great publicist of the first Christian emperor, the first in a long succession of ecclesiastical politicians, the herald of Byzantinism, a political theologian, a political metaphysician, and a caesaropapist. It is obvious that these are not, in the main, neutral descriptions. Much traditional scholarship, sometimes with barely suppressed disdain, has regarded Eusebius as one who risked his orthodoxy and perhaps his character because of his zeal for the Constantinian establishment." Hollerich concludes that "... the standard assessment has exaggerated the importance of political themes and political motives in Eusebius's life and writings and has failed to do justice to him as a churchman and a scholar".

While many have shared Burckhardt's assessment, particularly with reference to the Life of Constantine, others, while not pretending to extol his merits, have acknowledged the irreplaceable value of his works which may principally reside in the copious quotations that they contain from other sources, often lost.