Significant Changes in Homoousian Creeds in the Post-Nicene Era

The ‘Homoousian’ fathers were those church fathers who during the trinitarian controversies of the fourth century favored the Greek word ‘homoousias’, to describe the relationship of the Son to the Father. This word was employed in this manner by the Nicene Creed, and was highly controversial. To understand why the word was controversial we must first understand that it was a philosophical term not understood the same way by everyone.

Secondly we must note that its meaning prior to the trinitarian controversies of the fourth century was effectively equivalent to the modern English word “being”. Just as “being” in English can  be used in significantly different ways, to indicate either a nature/genus, or an individual (such a “human being”), so ‘ousia’ could be understood to indicate an individual, or a nature shared by many individuals. Therefore, when initially introduced to theological discussion, the word “ousia” was actually used to indicate an individual, with Sabellius, an early classical modalist, using the term ‘homoousias’ (same ousia) to say that the Father and Son were the same person. Similarly, Paul of Samosata used the term ‘homoousias’ to portray the Son as a part of the Father’s person, and thus the same person, or ‘homoousias’. This idea, and the word itself, were therefore condemned by church council, which rather proclaimed that Christ was ‘heteroousias’ or a different ousia, that is, in this usage, a distinct person.

When the Nicene Council used the term to describe the Son’s relationship to the Father, it was intended by its authors to be understood differently. Now, instead of ‘ousia’ indicating person, it was intended to indicate nature. Athanasius and the Nicene Council intended the word as used in the Creed to communicate that the Son of God, as His true Son and not merely a creature, shares His Father’s divine nature, and has the same divine nature as He. Thus ‘homoousias’ was intended to mean ‘same nature’, not ‘same person’ as heretics had previously used it.

While the intention behind the Nicene council’s use of the word was a good and orthodox one, changing the way the word was being used, and using a word that had been condemned as heretical, understandably resulted in widespread controversy, with the vast majority of Eastern bishops opposing the usage of the word for these reasons. They initially proposed the term ‘homoiousias’ instead, meaning “like ousia”; this was largely motivated not by thinking that the Son’s nature was not the same as that of the Father, but out of concern that saying the Son was the same ousia would be to say that the Son was the same person; therefore, they would declare that the person of the Son was like the person of the Father by the term ‘homoiousias’. They agreed that the Son had the same divine nature as the Father, but viewed ousia the same way it had previously been used, as equivalent to person. Therefore, it was blatantly modalistic in their thinking.

To add further difficulty, some of those who supported the Nicene Creed and use of the word ‘homoousias’ actually did intend it in a modalistic way, such as Marcellus of Ancyra, who was condemned for teaching modalism. The heretical usage of the term, therefore, was by no means a thing of the past. Just as many homoousian bishops, therefore, suspected those who rejected the term of Arian tendencies, the majority of orthodox Eastern bishops likewise suspected those who favored ‘homoousias’ of modalism.

With all these difficulties surrounding the terminology of ‘ousia’, which is not used in scripture, it is easy to see why eventually the church opted to give up the language of ‘ousia’ altogether and simply say that the Son was “like” (homoi) the Father. This likeness was understood to include that the Son had the same divine nature as the Father, although He is a distinct person from Him. This language prevailed for some twenty years until emperor Theodosius I purged the church of bishops who would not accept ‘homoousias’, and insisted that the Nicene formula be the lone confession of the church. After these decisions were made by the emperor without the consent of the church, the emperor called the council of Constantinople in 381 to make his decision official for the church, those who disagreed with his decision not being allowed to participate.

The church was now wholly homoousian, and things quickly went in a modalistic direction, although this was not how men like Athanasius and Hilary of Poitier had intended the word. By observing Creeds accepted by the homoousians after 381, we can see how things changed over the next few decades.

Whereas the first two ‘homoousian’ creeds, those of Nicea in 325 and Constantinople in 381, had both shared in common that they began by acknowledging “one God, the Father Almighty”, this important first article of the faith quickly disappears from later Creeds and confessions, despite the fact that this is not only the language and teaching of scripture, but was also the clear teaching of the ante-nicene fathers (see I believe in one God, the Father Almighty).

That the one God is the Father of the Lord Jesus Christ, His only-begotten Son, is an important point of Christian doctrine, and an integral part of classical trinitarianism as taught by scripture and witnessed to by the early church. But both due to semi-modalism’s emphasis on the “one essence”, or one divine nature shared by the persons as “one God”, as well as the association of the doctrine that ‘the one God is the Father in particular’ with Arianism, which had blended that scriptural truth with its errors, later Homoousian theologians greatly de-emphasized the church’s historic belief that the one God is the person of the Father in particular. Thus when we come to these creeds, we find a very lacking trinitarianism, and something that cannot be considered classical trinitarianism at all.

First let us examine an excerpt from the decision of the Council of Rome held in the same year as that of Constantinople, 381:

“If anyone shall think aright about the Father and the Son but does not hold aright about the Holy Ghost, anathema, because he is a heretic, for all the heretics who do not think aright about God the Son and about the Holy Ghost are convicted of being involved in the unbelief of the Jews and the heathen; and if anyone shall divide the Godhead, saying that the Father is God apart and the Son God, and the Holy Ghost God, and should persist that they are called Gods and not God, on account of the one Godhead and sovereignty which we believe and know there to be of the Father and of the Son and of the Holy Ghost -one God- or withdrawing the Son and the Holy Ghost so as to suggest that the Father alone is called God and believed in as one God, let him be anathema…

…This is the salvation of the Christians, that believing in the Trinity, that is in the Father and the Son and the Holy Ghost, and being baptized into the same one Godhead and power and divinity and substance, in Him we may trust.”

Much could be said on this. Let us note that there is a failure to identify the Father as the one God. The idea of doing so is mentioned only in respect to doing so in denial of the Son and Spirit’s divinity, which is condemned; yet that He is the one God, even while His Son and Spirit share His divine nature and have the same divine nature, is not explained. Not only is this significant change noteworthy, but we see that in place of the traditional grounding of monotheism, namely, the person of the Father as the one supreme uncaused Cause of all and one Supreme Authority over all, the grounding of monotheism is innovated to be the one common divine nature the persons share, and one lordship over creation They share (see Why Are We Monotheists?). Additionally, this is the among the earliest instances of a singular personal pronoun (“Him”) being used for the Trinity as a whole, or for the single divine nature the persons share; such language betrays the semi-modalism of the council.

In the previous centuries Rome had been home to multiple modalist bishops, such as Callixtus. Sabellius had been at Rome, as had Noetus. One must wonder from this and following developments if Rome ever truly supported an orthodox understanding of ‘homoousias’, or if they accepted it so readily during the fourth century controversies as a convenient way to express their own native modalism. Certainly this would not be the last step that Rome took to lead the church away from classical trinitarianism to semi-modalism, as the papal anti-christ later officially redefined the concept of co-essentiality in a semi-modalistic way in the Fourth Lateran Council.

Next we see the Creed of the First Council of Toledo (400 AD):

“1. We believe in one true God, Father and Son and Holy Spirit, creator of that which is visible and invisible, through whom everything in heaven and on earth was created.

2. This one God also has one divine name – the Trinity.

3. The Father is not the Son, but he has the Son, who is not the Father.

4. The Son is not the Father, but is by nature the Son of God.

5. Also the Spirit is the Paraclete, who himself is neither the Father nor the Son, but proceeds from the Father.

6. Therefore the Father is unbegotten, the Son begotten, the Paraclete not begotten, but is proceeding from the Father

7. It is the Father whose voice is heard from heaven saying, “This is my beloved Son, in whom I am well pleased. Listen to him.”

8. It is the Son who said, “I came forth from the Father and I came into this world from God.”

9. It is the Paraclete himself about whom the Son said, “Unless I go to the Father, the Paraclete will not come to you.”

10. This Trinity is distinct in persons, of one substance, virtue, power and undivided majesty, unable to be differentiated.

11. Besides him there is no one else with a divine nature, neither angel nor spirit nor anything else of excellence which one ought to believe to be God.

12. Therefore, this Son of God, being God, born from the Father before everything, the beginning of all, made holy the womb of the blessed Virgin Mary and assumed true humanity from her without procreation through a man’s seed,

13. that is, the Lord Jesus Christ.

14. His body was neither imaginary nor did it merely have form but had substance.

15. And so he had hunger and thirst and suffered pain and wept and felt every kind of bodily hurt.

16. In the end he was crucified, died and was buried, and rose on the third day;

17. afterwards he spoke with his disciples;

18. he ascended to heaven on the fortieth day.

19. This Son of Man is also named the Son of God; however, the Son of God is God and should not be called a son of man.

10. We truly believe in the resurrection of the human body.

21. However the soul of man is not a divine substance or a part of God, but rather a creation which by divine will is imperishable.


1. Therefore if anyone should say or believe that this world was not made by the omnipotent God and his instruments, let him be anathema.

2. If anyone should say or believe that God the Father is himself the Son or the Paraclete, let him be anathema.

3. If anyone should say or believe that God the Son is himself the Father or Paraclete, let him be anathema.

4. If anyone should say or believe that the Paraclete, the Spirit, is either the Father or the Son, let him be anathema.

5. If anyone should say or believe that the human Jesus Christ was not assumed by the Son of God, let him be anathema.

6. If anyone should say or believe that the Son of God as God suffered, let him be anathema.

7. If anyone should say or believe that the human Jesus Christ, as a human, was incapable of suffering, let him be anathema.

8. If anyone should say or believe that there is one God of the Old Testament and another of the Gospel, let him be anathema.

9. If anyone should say or believe that the world was made by another God that by the one of whom it is written, “In the beginning God created the heavens and the earth,” let him be anathema.

10. If anyone should say or believe that the human body will not rise after death, let him be anathema.

11. If anyone should say or believe that the human soul is a part or substance of God, let him be anathema.

12. If anyone should say or believe that there is another Scripture than that which the Catholic Church accepts or believes to be held as authoritative or has venerated, let him be anathema.” (Translated by GLT and PSAM- source )

Here we see again that the first article of the faith is neglected, and in its place, the Trinity is identified as the one God of Christianity. Rather than identifying the one God with the Father as scripture does, the one God is given the name “Trinity”. Modalism is ostensibly avoided by declaring that the Father, Son, and Spirit are not each other; the issue of making Them out to be a single person, which is the heart of the modalist heresy, is not directly addressed.

Signs of semi-modalism can be found in this Creed, but it is not as explicit as other authors such as Augustine make it. In points 10-11 of the Creed, we see the Trinity get identified as a “him”; which serves to illustrate that when the Trinity is made out to be the one God, conceiving of it as a person is soon to follow, for it is obvious that the one God is a person. The misidentification of the this person with the Trinity as a whole, rather than as the person of the Father as scripture reveals, is heterodox, and indicative of semi-modalism.

Were the Homoiousians Right?

“Homoi-ousias”, which means “like essence” was the Greek word favored by the conservative majority of bishops during the Arian controversy of the fourth century to describe the essential relationship between the Son and the Father. It was put forward as a suggested alternative to the word employed by the Council of Nicea “Homo-ousias”, which means “same essence”, and to the Arian term “Heteroousias”, meaning “different essence”. As Hilary of Poitiers explains in De Synodis (see Hilary of Poitiers on Correct and Incorrect Understandings of Co-essentiality), both ‘Homoiousias’ and ‘Homoousias’, when understood in an orthodox fashion, mean the same thing. If the Son and Father have the same divine nature, or essence, as scripture teaches, then certainly “homoousias” is a fitting word; yet likewise, saying that the Son is like the Father in His essence, meaning, that He is exactly like the Father in His essence, or identical to Him, as can be indicated by “homoiousias”, means the same thing.

But both of these words (as nearly all words do) have a variety of possible meanings; they can each be taken in multiple different ways. For this reason, they were not always meant or understood in an orthodox fashion in the Nicene controversy; both words had ways they could be understood that are heretical. ‘Homoiousias’ allowed for moderate Arians to accept the term because ultimately saying that the Son is of ‘like essence’ with the Father can be taken either as ‘exactly alike’ (which is orthodox), or merely ‘similar, with minor differences’ (which is Arian). For this reason the pro-Nicene, and thus pro-‘homoousian’ minority frequently leveled the charge against the homoiousians that they were semi-arian (even while many of them, ultimately, were not).

Likewise “homoousias” could also be taken in a heretical way, in a modalistic fashion, in which “same essence” was not intended to mean that the Father and Son were distinct persons who shared a common divine nature, but rather that the Father and Son were somehow one subsistent or personal thing.

“Essence” or Greek ‘ousia’ in general was not spoken of nearly as much in the pre-nicene era; it was once the Nicene Council introduced ‘homoousias’ into the Creed that the alternative ‘homoiousias’ became popular. Why? Because not only was it possible to misunderstand ‘homoousias’ in such a way that it would mean that the Father and Son were ultimately a single person, but the word actually already had a history of being used that way by the time of the Arian controversy. Thus, many orthodox bishops desired another term to use.

“Homoousias” was associated with Sabellius, an early modalist, and was also used by later ante-nicene modalist Paul of Samosata. The local council which condemned his teaching as heretical actually condemned the word “homoousias” as heretical, as well, on the basis of its modalistic usage. For this reason when this word which had a strong association with modalism, and tendency to be understood in a modalistic way, was employed by the Nicene Council, many of the church fathers at the time objected, although the orthodox ‘Homoousian’ fathers made efforts to explain to orthodox meaning of the word which they intended to communicate by it.

Eventually, with much explaining, “homoousias”, despite the grave concern by many that the word was modalistic, won the day, eventually being accepted at the Council to Constantinople in 381. “Homoiousias” came to be associated with the “semi-arians”, and eventually with Arianism at large, as time went on, in large part thanks to the polemics of semi-modalists in centuries following. From the time of the Nicene controversy onward, it has been a popular polemic against anyone not favorable term ‘homoousias’ to label them as being in some way Arian, even when the difference is merely one of terminology and not meaning.

However, this language of the Son being “homoousias” with the Father did not take long to again take on an ultimately modalistic meaning, as semi-modalism redefined the entire concept of consubstantiality which the word stood for to mean that the Father and Son were ultimately a single person, “God the Trinity”. Such redefining can be seen in the Fourth Lateran Council, as well as in the influential writings of Augustine (see Augustine’s Trinitarian Heresy). The concept of co-essentiality was twisted to no longer mean that the persons of the Son and Holy Spirit have the same divine nature as the Father, but rather to say that the Father, Son, and Spirit are all one subsistent thing, or person. Thus a term that had indicated generic unity, or identicality of nature, was now altered to indicate that the three persons of the Trinity were numerically one, or one person.

Those homoiousian Christians of the fourth century then, as well as those who favored the term “homoian” (which sought to leave the unscriptural term “essence” or “ousia” out of the discussion altogether, and merely confess that the Son is “like” the Father) were ultimately vindicated in their misgivings about the term “homoousias”. They protested it for fear it was Sabellian- that was its history, and it was worried that it would again be taken in such a way in the future. The Homoiousians and Homoians (who were slandered as being Arian by the Homoousian minority) were right; this is exactly what happened.

Although they are often slandered for their misgivings about the word, the Homoian and Homoiousian bishops of the fourth century have ultimately been vindicated in respect to their distrust of the word ‘homoousias’. The very thing they warned could happen did, in the post-nicene era.

While homoousian consubstantiality, as intended by its original authors such as Athanasius, is entirely orthodox, it introduced a shift in emphasis from the persons of the Trinity to the divine nature They share, and an emphasis on this one divine nature being the “one God” of Christianity. Perhaps in overreaction to Arianism, Homoousian Christians eventually gave up the confession that the one God is the Father, and instead emphasized the divine nature as Christianity’s one God.

This shift in language was doomed to result in semi-modalism. In scripture, the “one God” is always a person, and such is the natural way to think of God: as personal. Scripture, however, as the early church did, specifies that this one God is the person of the Father in particular; the Son is His Son, the Holy Spirit, His Spirit (see I believe in one God, the Father Almighty). By shifting the focus onto the essence as the one God of Christianity, Homoousian Christians in the post-nicene era doomed the church to fall into thinking of the essence as a person, therefore, since the one God is a person. Using what was ultimately the title of a single person for the divine nature shared by all three persons led to natural confusion, and what we see down to the present day, a personifying of the divine nature as a fourth person in the Trinity (see Semi-modalism and the Introduction of a Four-Person Trinity).

The homoousians didn’t merely pioneer this change in language, but emphasized conceptually that monotheism depended on the fact that there is one divine nature shared by the persons of the Trinity. While this fact is true, the unity of God does not depend on the fact that there is one divine nature, but on the fact that there is one Father, one supreme uncaused Cause of all, and Supreme Authority over all. For in the case of three men there is also a unity of nature, one human nature being common to all human persons; yet all human persons are not one man, but many men. And besides, even the fact that the persons all share one divine nature is dependent on the person of the Father, since He is in Himself the very definition of that divine nature, without cause or source; and yet is Himself the Source of that divine nature to His Son and Spirit, as They have the divine nature from the Father in eternal generation and procession, respectively.

This emphasis, then, on the divine nature as the unity of God, instead of the Father, has proven detrimental throughout the many centuries since. Semi-modalism easily grows out of such an emphasis, because, as mentioned above, three persons merely being of one nature does not make them “one God”, any more than three men being of one human nature makes them one man. If then, this unity of nature is insisted on as the explanation of Christian monotheism, is necessarily must be altered to mean something beyond a mere unity of nature: a unity of person. To deny the charge of tritheism on the basis of a Nicene understanding of co-essentiality alone is impossible; therefore, since the classical grounding of monotheism was abandoned, the new one developed was to redefine co-essentiality to mean not merely that the three persons share one essence, but are one “being”; a vague term, which, in fact, ends up being conceptually equated with person (see also Equivocation Over the Term “Person”).

Because this is recognized as modalistic to treat the three persons as one person, the language of the three being one “person” was never embraced by the church broadly; yet conceptually, that is what co-essentiality has been redesigned to signify in the post-nicene understanding. Accordingly, the response of those committed to a post-nicene scholastic redefinition of co-essentiality, as can be seen in the Fourth Lateran Council (see The Grievous Error of the Fourth Lateran Council), is to accuse those articulating a classical understanding of co-essentiality of being tritheists, failing to recognize that the grounding of Christian monotheism is not that the Son and Spirit of God share His divine nature (although this is true), but that there is one supreme uncaused Cause of all, Who is one Supreme Authority over all, the Father (see Why There is Only One God: One Supreme Cause and Why There is Only One God: Headship).

It was not, therefore, the emphasis on the persons of the Trinity sharing one essence, or one divine nature, that was the fatal flaw of homoousian theology, so to speak, but the Homoousians’ emphasis of this unity of nature as the grounding of Christian monotheism, combined with the abandonment of the classical grounding of Christian monotheism. This unbiblical shift led directly into the widespread acceptance of semi-modalism, to the destruction of the classical trinitarianism the original Homoousians contended for.

Arianism, with its emphasis on the Father’s role as the one God, the supreme uncaused Cause of All, and the Supreme Authority over all, served as a catalyst for this change, as these ideas naturally became associated with a heretical Christology. The result of this was important aspects of classical trinitarianism being divided up between Arianism and the Homoousians; the Arians emphasizing the Father as the one God, and ground of monotheism, and the Homoousians emphasizing the co-divinity of the persons of the Son and Holy Spirit with the Father. While Arians always rejected the Homoousian emphasis, initially Homoousian Christians accepted the Arian emphasis as an aspect of orthodox trinitarianism. But as time went on, Arian association with these ideas led to a de-emphasizing of these concepts in Homoousian theology, although they were never actually repudiated. Arianism can thus be argued to have done more damage to the cause of classical trinitarianism by stigmatizing elements of classical trinitarianism by association with its heresy than it did by actually promulgating a heretical Christology, which over the scheme of history has ultimately not been successful in maintaining a large following. But by attacking the classical trinitarian doctrine of the Son and Spirit’s co-divinity with the Father, Arianism enticed the church to over-react in the opposite direction by overemphasizing the doctrine of co-essentiality to the eclipsing of other elements of classical trinitarianism.

The first cracks in Homoousian theology can be seen within its first generation, which accepted the classical trinitarian doctrines that the Father is the one God, the supreme uncaused Cause of all, and the Supreme Authority over all, as they shifted emphasis from these doctrines to the fact that the Son and Spirit share the Father’s divine nature. In order to emphasize the truth of the Son and Spirit’s co-essentiality with the Father, otherwise orthodox Homoousian theologians began twisting scripture to read it as speaking of the divine nature, rather than the person of the Father, in certain passages; the first intimations of the semi-modalism that would sweep the church in the following generations.

For example, Athanasius wrote:

“For what is nearer [God] than the Cherubim or the Seraphim? And yet they, not even seeing Him, nor standing on their feet, nor even with bare, but as it were with veiled faces, offer their praises, with untiring lips doing nought else but glorify the divine and ineffable nature with the Trisagion. And nowhere has any one of the divinely speaking prophets, men specially selected for such vision, reported to us that in the first utterance of the word Holy the voice is raised aloud, while in the second it is lower, but in the third, quite low,—and that consequently the first utterance denotes lordship, the second subordination, and the third marks a yet lower degree. But away with the folly of these haters of God and senseless men. For the Triad, praised, reverenced, and adored, is one and indivisible and without degrees (ἀσχηματιστός). It is united without confusion, just as the Monad also is distinguished without separation. For the fact of those venerable living creatures (Isa. vi.; Rev. iv. 8) offering their praises three times, saying ‘Holy, Holy, Holy,’ proves that the Three Subsistences443 are perfect, just as in saying ‘Lord,’ they declare the One Essence.” (Athanasius, On Luke 10:22)

Ambrose of Milan, of the first generation of post-nicene Homoousians, similarly wrote:

“Dominations and powers fall down before Him — you speak evil of His Name! All His Saints adore Him, but the Son of God adores not, nor the Holy Spirit. The seraphim say: Holy, Holy, Holy! Isaiah 6:3

107. What means this threefold utterance of the same name Holy? If thrice repeated, why is it but one act of praise? If one act of praise, why a threefold repetition? Why the threefold repetition, unless that the Father and the Son and the Holy Spirit are one in holiness? The seraph spoke the name, not once, lest he should exclude the Son; not twice, lest he should pass by the Holy Spirit; not four times, lest he should conjoin created beings [in the praise of the Creator]. Furthermore, to show that the Godhead of the Trinity is One, he, after the threefold Holy, added in the singular number the Lord God of Sabaoth. Holy, therefore, is the Father, holy the Son, holy likewise the Spirit of God, and therefore is the Trinity adored, but adores not, and is praised, but praises not.” (Ambrose of Milan, De Fide, Book 2, Chapter 12)

Both Athanasius and Ambrose explain the vision of Isaiah 6 as pertaining to the whole Trinity, instead of the Father, as can be understood from the parallel passage in Revelation 4 (see Examining Scripture: The “Lord God Almighty” of Revelation Chapter 4). They both read a Homoousian understanding of the Trinity -with its supreme emphasis on the unity of the divine nature- into the passage, explaining the three repetitions of “Holy” as indicating the three persons, and the singular “Lord God” as indicating the singular essence, or divine nature. This interpretation is seriously flawed, choosing to forcibly insert Homoousian theology into scripture where it is not spoken of, contrary to the interpretation offered in the New Testament in Revelation 4 which clarifies this as referring to the person of the Father, “the Lord God Almighty,” alone.

What may also be noted here is that although both Ambrose and Athanasius usually avoid treating the Trinity as a person (unlike later generations of Homoousian theologians), by making this strained interpretation of the passage in order to seemingly provide more biblical support for Nicene trinitarianism, they fall into regarding the Trinity as a single person; for the vision in Isaiah 6 clearly treats the “Lord God” on the throne not as an impersonal essence, as the divine nature considered in abstract is, but as a person, who speaks to Isaiah and sends him as a prophet.

By taking passages of scripture that refer to a single person of the Trinity and saying they speak of the essence, the groundwork for future semi-modalism was laid, which would blatantly treat the essence or Trinity as a whole as a person. Although this misinterpretation can be regarded as a relatively minor mistake on its own, it would be amplified into a completely different theology by later theologians, such as Augustine of Hippo (see Augustine vs. Athanasius on the Identity of the “One God”).