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"Homoousios" (of the same substance)

In the 4th century AD the church was embroiled in a bitter controversy over the nature of Christ, and his relationship to the Father. A pastor and teacher named Arius believed and taught what came to be called Arianism: that God was greater than His Son, as a father must be superior to a son, and that the Son in turn had a literal beginning -- thus, that he did not exist from all eternity, as had his Father. In general outline, at least, this was much closer to the truth of the Bible than were the "orthodox" views of the time -- which should be considered the beginnings of the formulation of the false doctrine of the Trinity.

While the whole content of the Arian position was condemned by the orthodox church, the terms of the debate turned upon two very similar Greek words: "homoousios" and "homoiousios". The difference was that the second word had one letter added, an iota. But the difference in meaning was very significant. The supporters of Arianism claimed that the Son was subordinate to the Father, who was the one true God. Thus they believed the Son was 'like or similar in substance' ["homoi" = similar] to the Father, but not identical. The word they used to denote the SIMILAR (but not exact) substance was "homoiousios".

However, the Council of Nicea selected the word "homoousios" for what came to be called the Nicene Creed. [See Lesson, Nicene Creed] This word means 'of one or the same substance'; thus the Church insisted on the essential and absolute unity of the Father and the Son; in English translation: "And [I believe] in one Lord Jesus Christ, the only-begotten Son of God... being OF ONE SUBSTANCE with the Father..."

[The actual words, "homoiousios" and "homoousios", do not appear in the text of the NT. The root word, "ousios", does occur -- but only twice: in Luke 15:12,13, in the parable of the Prodigal Son, where it signifies the possessions of the father, and the inheritance of the son. It is derived from the verb "to be", and thus seems to suggest -- very fundamentally (but also very vaguely and flexibly) -- what one is or what one has. (It may have been this very vagueness, as applied to what God the Father and His Son share, that commended this word and its derivatives to the different camps of bishops!)]

Thus the only difference in the two terms was the Greek letter iota (similar to the English letter i) between the two halves of the words; this significantly changed the meaning of the first part of the word -- either "homo" (the same or identical) or "homoi" (similar). Later this doctrine summarized in "homo-ousios" was expanded to teach, even more fully, the one substance of the Father, the Son, and the Holy Spirit -- ie the Trinity!


Arianism Versus the Council of Nicaea


The Church emerged in a world which reflected both Jewish and Greek values. One question occupying this non-Christian world was the contrast between the "One and the Many, between the ultimate unity that lay behind the visible universe and the incalculable variety that exists in the world" (Ward 1955, 38). In short, philosophers were already questioning and seeking to understand the relationship between a Creator-God and the world which He had made.

The Jews believed in one unique and supreme God who created by His word. They generally saw this "Word" as an Eternal Wisdom from the one God -- the Word which He pronounced in the beginning, or the Wisdom which He created. Thereby the Father communicated Himself to man (Guitton 1965, 81).

The Greeks, on the other hand, could not see how a finite and changeable world could come from an eternal and changeless God. They proposed the idea of a "mediating Intelligence, a first emanation of the first principle which reduced the distance between God and the world" (Guitton 1965, 81) -- a sort of semi-God who bridged the gap between a perfect God and an imperfect world.

The Church, as it developed its teachings, felt the need to "reconcile the notions they had inherited from Judaism with those they had derived from Greek philosophy. Jew and Greek had to meet in Christ. They sought to find an answer that would agree with the revelation they had received from Christ as recorded in the scriptures" (Ward 1955, 39). (It may be observed that, as more time passed, the official Church and its teachings got further and further from this presumed purpose.) This struggle for a reconciliation of thought reached one climax with the Arian controversy. The Church responded with the First Ecumenical Council of Nicaea that sought to bring together Scriptural and philosophical thought to explain the "Trinity". The Council did triumph over Arianism but only after fifty years of bitter battling. Imperial support (which wavered back and forth) as well as confusion in theological terminology (which included difficulties in translating complex terms from Greek to Latin, and vice versa) were the principal reasons for such a long drawn-out battle.

Arius and His Teaching

Arius, who was born in Egypt in 256 AD, was a parish priest in Alexandria. He had studied under Lucian of Antioch, the founder of the school of Antioch, who had earlier been condemned for holding that Christ was only a man; although he was later reconciled. Lucian is called the "Father of Arianism" because "Arius and almost all the 4th-century Arian theologians were his students. Calling themselves Lucianists and Collucianists, they developed his subordinationist tendencies into a full heresy" -- so writes a Catholic historian (Harkins 1967, 1057,1058). (Of course, "subordinationist" tendencies might properly describe just what Christadelphians believe today: ie, that Jesus was a begotten Son and thus subordinate, or subject, to his Father.)

With this background Arius struggled with the question of the Trinity. His teaching in Alexandria was as follows: "Personal distinctions were not eternally present within the nature of God... the Godhead Himself was responsible for them... Identifying the eternal Godhead with the Father and regarding the Logos as no more than a power or quality of the Father, Arius said that before time began the Father had created the Son by the power of the Word to be His agent in creation. The Son was not therefore to be identified with the Godhead. He was only God in a derivative sense, and since there was a time when he did not exist he could not be eternal. Arius stressed the subordination of the Logos to such an extent as to affirm his creaturehood, to deny his eternity and to assert his capacity for change and suffering" (Ward 1955, 41). This teaching of Arius "drove the distinctions outside the Deity and thus destroyed the Trinity. It meant solving the difficulty of the One and the Many by proposing a theory of one Supreme Being and two inferior deities" (Ward 1955, 43). The Person of Christ "belonged to no order of being that the Church could recognize... He was neither God nor man" (Ward 1955, 42). [It ought to be noted here that, while Arius denies the teaching of the Trinity, as described by the pro-Catholic historians above, his view of Christ's "creation" and involvement in the literal creation of the world were certainly not scriptural either.]

Arius versus the Alexandrian bishop

Arius' views began to spread among the people and the Alexandrian clergy. Alexander the bishop called a meeting of his priests and deacons. The bishop insisted on the unity of the Godhead. Arius continued to argue that, since the Son was begotten of the Father, then at some point he began to exist. Therefore there was a time when the Son did not exist. Arius refused to submit to the bishop and continued to spread his teaching. Alexander called a synod of bishops of Egypt and Libya. Of the hundred bishops who attended, eighty voted for the condemnation and exile of Arius. After the synod Alexander wrote letters to the other bishops refuting Arius' views. In doing so the bishop Alexander used the term "homoousios" to describe the Father and Son as being of one substance. This term "was to become the keyword of the whole controversy" (Ward 1955, 43,44).

With the decision of the synod Arius fled to Palestine. Some of the bishops there, especially Eusebius of Caesarea, supported him. From here Arius continued his journey to Nicomedia in Asia Minor. The bishop of that city, also named Eusebius, had studied under Lucian of Antioch. He became Arius' most influential supporter. From this city Arius enlisted the support of other bishops, many of whom had studied under Lucian. His supporters held their own synod, which found Arius' views to be correct, and condemned Bishop Alexander of Alexandria. Arius seemed to have good grounds for this condemnation. The term "homoousios" was rejected by Alexander's own predecessor Dionysius when arguing against the Sabellians (a group who claimed the Father and Son were absolutely identical).

All this controversy was taking place just as the Church was emerging from Roman oppression -- so that Imperial involvement in these matters would add more twists and turns to future events.

Constantine and Ossius

With the rise of Constantine to power, Christianity became the religion of the Roman Empire. Constantine had politically united the Empire but he was distressed to find a divided Christianity. Constantine, who most certainly did not understand the full significance of the controversy, sent Ossius his main ecclesiastical adviser with letters to both Alexander and Arius. In the letters he tried to reconcile them by saying that their disagreement was merely a matter of words. He felt that both of them really were in agreement on major doctrines and neither were involved in heresy. The letters failed to have any calming effect.

In 325 AD Ossius presided over a Council of the Orient in Antioch that was attended by 59 bishops, 46 of whom would soon attend the Council of Nicaea. This Council in Antioch was a forerunner of the latter Council in Nicaea. Under the influence of Ossius a new Church practice was inaugurated -- that of issuing a creedal statement. At this Council Arianism was condemned, a profession of faith resembling the Alexandrian creed was promulgated, and three bishops who refused to agree with the teaching of this Council were provisionally excommunicated until the Council of Nicaea.

In the summer of that year, probably under the suggestion of Ossius, Constantine called for a general council of the Church at Nicaea in Bithynia. That an Emperor should invoke a Council should not be considered unusual, since in Hellenistic thought he "was given by God supreme power in things material AND spiritual" (Davis 1987, 56).

The Council of Nicaea

The General Council was well attended by the major church leaders of the Eastern Empire. Some Western bishops were also present. Because of old age and sickness, Sylvester the bishop of Rome (whom Catholic historians call "Pope Sylvester"!) did not attend but sent two representatives. The total number of bishops who attended the Council has been disputed. Eusebius of Caesarea, who attended, claimed there were 250; Athanasius, also in attendance, mentioned 300; modern scholars put the number at 220.

If there were minutes taken of the Council proceedings they are no longer in existence. We know from the writings of Rufinus that "daily sessions were held and that Arius was often summoned before the assembly; his arguments attentively considered. The majority, especially those who were confessors of the Faith, energetically declared themselves against [what they called] the impious (!) doctrines of Arius" (LeClercq 1913, 45).

Concerning the Creed that was drafted at the Council, "Eusebius of Caesarea, Athanasius of Alexandria and Philostorgius have given divergent accounts of how this Creed was drafted" (DeClercq 1967, 792). But it appears, from one reconstruction of the events, that Eusebius of Nicomedia offered a creed favorable to Arian views. This creed was rejected by the Council. Eusebius of Caesarea proposed the baptismal creed used in Caesarea. Although accepted it does not seem to form the basis of the Council's Creed. Attempts were made to construct a creed using only scriptural terms. These creeds proved insufficient to exclude the Arian position. [Of course they did! How could Scriptural terms exclude a Scriptural idea?!] "Finally, it seems, a Syro-Palestinian creed was used as the basis for a new creedal statement... The finished creed was preserved in the writings of Athanasius, of the historian Socrates and of Basil of Caesarea and in the acts of the Council of Chalcedon of 451" (Davis 1987, 59). When the creed was finished, eighteen bishops still opposed it. Constantine at this point intervened to threaten with exile anyone who would not sign it. Two Libyan bishops and Arius still refused to accept the creed. All three were exiled.

The Creed and an Analysis

Some parts of the literal translation of the Nicaea Creed are as follows:

"We believe in one God the Father Almighty, Maker of all things visible and invisible; and in one Lord Jesus Christ, the only begotten of the Father, that is, of the substance (ousia) of the Father, God of God, light of light, true God of true God, begotten not made, of the same substance (homoousios) with the Father, through whom all things were made both in heaven and on earth... Those who say: 'There was a time when He was not, and He was not before He was begotten;' and that 'He was made out of nothing;' or who maintain that 'He is of another hypostasis or another substance,' or that 'the Son of God is created, or mutable, or subject to change,' the Catholic Church anathematizes [condemns]" (LeClercq 1913, 45).
In case the creed was not enough to end the Arian controversy, anathemas (official, formally pronounced judgments) were attached directly condemning Arian positions (think of these as "doctrines to be rejected" by the emerging Catholic church!):

Terminology Problem

A very important term used by the Council was "homoousios". At that time this word could have three possible meanings. "First, it could be generic, ie, of one substance; and could be said of two individual men, both of whom share human nature while remaining individuals. Second, it could signify numerical identity, that is, that the Father and the Son are identical in concrete being. Finally, it could refer to material things, as two pots are of the same substance because both are made of the same clay" (Davis 1987, 61). The Council intended the first meaning -- so as to stress the equality of the Son with the Father. If the second meaning for the word was taken to be the Council's intention, it would mean that the Father and Son were identical and indistinguishable -- this was a "heresy" even to the Catholic Church at this point! The third meaning gave the word a materialistic tendency that would imply that the Father and Son are parts of the same stuff.

The Council's defeat by Arianism

It is not surprising -- given the possible differences in meaning of the word as outlined above -- that the Council by using the word "homoousios" could be called into question. And of course, the need to translate between Greek and Latin probably in some cases contributed to the confusion and misunderstanding.

Bishop Eusebius of Nicomedia gained the confidence of Emperor Constantine. He convinced Constantine that the Council's use of the word "homoousios" (suggesting that Father and Son were identical) was heretical. The Emperor now favored the Arians. With the death of Constantine the Empire was divided between his sons. Constans who ruled in the West favored Nicaea while his brother Constantius who ruled the East was anti-Nicaea. Supporters of Nicaea in the East -- especially Bishop Athanasius -- were deposed and excommunicated by the Dedication Council of Antioch. This Council directly attacked the Nicaea Council by promulgating its own creed that omitted the phrases "from the substance of the Father" and "homoousios." Some attempts were made to find a substitute word for "homoousios". As many as fourteen Councils were held between 341 and 360 "in which every shade of heretical subterfuge found expression... The term 'like in substance,' homoiousios... had been employed merely to get rid of the Nicene formula" (Barry 1913, 709).

Not all Arians agreed with this new word, however. One group emphasized that the Father and Son were in fact "not similar" -- or "anomoios" (the "a" or "an" prefix signifying "NOT") -- while another group used the word "similar" or "homoi" to describe the Father and Son relationship. [Thus at least groups may now be discerned: the "Homo" (identical) group; the "Homoi" (similar) group; and now the "Anomoi" (not similar) group!]

With the death of Constans in 350 his anti-Nicaea brother Constantius became sole ruler of the Empire. The new Emperor demanded that all the bishops of his Empire should agree with the homoios ("similar") formula. In 359 he summoned two Councils, one in the East at Seleucia and the other in the West at Rimini. Both Councils, under the Emperor's threats and with rationalizing arguments aimed at calming consciences, were induced to sign the homoios formula. This "homoios" (similar) victory "was confirmed and imposed on the whole Church by the Council of Constantinople in the following year" which condemned the terms homoousios ("identical") and anomoios ("not similar") (Ward 1955, 57). Now it seemed that the Arians had triumphed over the Nicaea creed.

The Final Battle

The seeming triumph of homoiousios ("similar substance") was short-lived. First it gained its popularity solely by imperial imposition, and with the death of Constantius in 361 it collapsed. Athanasius reasserted the homoousios ("identical substance") position, and brought other church leaders to the "realization" that the three Persons as God must share the same identical substance also.

In the West Ambrose of Milan led the fight for the Nicene Creed. At the Council of Sirmium in 378, with the support of the Western Emperor Gratian, six Arian bishops were deposed. A series of laws were passed in 379 and 380 by the Emperor which prohibited Arianism in the West.


The Council of Nicaea was victorious in the end. It took over fifty years of bitter battling between the upholders of the Council of Nicaea and those against it. The Arian "heresy" seemed finished when the Council so specifically anathematized their teachings one by one.


Works Cited (essentially pro-Catholic publications):

  1. The New Catholic Encyclopedia. 1967. New York: McGraw-Hill Book Co, Vol 1: Arianism, by VC Declercq.
  2. The New Catholic Encyclopedia. 1967. New York: McGraw-Hill Book Co, Vol 8: St Lucian of Antioch, by PW Harkins.
  3. Davis, SJ, Leo D. 1987. The First Seven Ecumenical Councils (325-787): Their History and Theology. Wilmington: Michael Glazier, Inc.
  4. Guitton, Jean. 1965. Great Heresies and Church Councils. New York: Harper and Row.
  5. Herbermann, Charles G, Edward A. Pace, Conde B. Pallen, Thomas J. Shahan, John J. Wynne, editors 1913. The Catholic Encyclopedia. New York: The Encyclopedia Press, Vol 1, Arianism, by William Barry.
  6. Herbermann, Charles G., Edward A. Pace, Conde B. Pallen, Thomas J. Shahan, John J. Wynne, eds. 1913. The Catholic Encyclopedia. New York: The Encyclopedia Press. Vol 11, Councils of Nicaea, by H Leclercq.
  7. Ward, DD, Bishop JWC 1955. The Four Great Heresies. London: A.R. Mowbray and Co Ltd.
[For a timeline, see Lesson, Arian controversy.]

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