Semi-Arianism refers to a theological position that emerged in the 4th century as an attempt to find a middle ground between the teachings of Arius and the formulation agreed upon at the First Council of Nicaea in 325 AD. Arius taught that the Son was created by the Father and therefore subordinate to Him and of a different essence or substance. The Council of Nicaea affirmed that the Son is “begotten not made” and is of the same essence (homoousios) as the Father. Semi-Arianism affirmed that the Son was begotten by the Father but denied that the Son is of the same essence as the Father, preferring to say that the Son is of similar essence (homoiousios) to the Father.
The Semi-Arians argued that while the Son was eternal and divine, the Father alone was unbegotten, underived, and without beginning. The Son was begotten of the Father, and therefore had a beginning and was subordinate in terms of authority. They wanted to avoid the extreme subordinationism of Arius while also steering clear of the “sabellianism” they perceived in the creed of Nicaea which seemed to threaten the personal distinctions between the Father and Son.
Some key figures associated with Semi-Arianism were Basil of Ancyra, Macedonius I of Constantinople, and Eustathius of Sebaste. Basil affirmed at the Council of Constantinople in 360 that the Son was “like” the Father but not of the same essence. Macedonius spoke of the Son as a “creation” of the Father and a servant who was to be “worshipped but not adored.” Eustathius seemed to affirm both homoiousios and homoousios at different times, attempting to straddle the divide.
The pro-Nicene party condemned Semi-Arianism as a compromise position that undermined the full divinity of Christ. Athanasius argued vigorously against it, asserting that an essence that is only similar to God’s is actually foreign to Him. The Cappadocian Fathers – Basil the Great, Gregory of Nyssa, and Gregory of Nazianzus – also wrote passionately in defense of the Nicene formulation.
The conflict between Semi-Arianism and pro-Nicene orthodoxy was for the most part resolved at the First Council of Constantinople in 381 which affirmed the Nicene Creed and the full divinity of the Son in no uncertain terms. However, Semi-Arian groups persisted for a couple more decades among the Germanic Gothic tribes. Ulfilas, the Goth’s missionary bishop, propagated Semi-Arianism among them in the 4th century. But by the end of the 5th century these groups had either disappeared or conformed to orthodoxy.
While Semi-Arianism was declared heretical, and rightly so considering its deviation from biblical orthodoxy, it does highlight the difficulty that the early church encountered in articulating how the Son is both fully divine yet also eternally begotten from the Father. The creed adopted at Constantinople clarified the issue by affirming that the Son was begotten from the Father’s essence before time. Ultimately we must affirm what scripture clearly teaches: Jesus Christ is the eternally begotten Son of God, fully divine, yet personally distinct from the Father, through whom the universe was created and salvation accomplished (John 1:1-3, 14, 18, 3:16, Colossians 1:13-20, Hebrews 1:1-4).
The Background and Origin of Semi-Arianism
Semi-Arianism emerged following the Council of Nicaea in 325 AD which was convened to address the teachings of Arius (c. 250-336), a presbyter in Alexandria. Arius taught that only the Father was the one true God. The Son was essentially created by the Father as the first act of creation, and therefore did not exist eternally with the Father. Since the Son was created out of nothing, the Son was not of the same essence (Greek: homoousios) as the Father, but was only like Him (homoiousios). Furthermore, since the Son owed his existence to the Father’s will, the Son was subordinate to the Father in terms of authority.
Arius’ teachings gained a large following in the Eastern Roman Empire but also stirred much controversy. Alexander, the bishop of Alexandria, condemned Arius and had him excommunicated. Constantine, wanting to resolve this doctrinal dispute, called for the first ecumenical council of bishops to meet at Nicaea in 325 AD. Around 300 bishops attended along with the emperor. After much debate, the Council formulated a creed (the Nicene Creed) which stated that the Son was “begotten not made, of one essence (homoousios) with the Father.” This challenged Arius’ subordinationism and affirmed the full divinity of the Son as being of the same divine essence as the Father.
However, the debate did not end there. Some bishops like Eusebius of Caesarea were uneasy with the homoousios language, fearing that it blurred the distinction between the Father and the Son and failed to safeguard the Father’s role as the “fount” of divinity. They preferred to say the Son was homoiousios or of “like essence” rather than of the “same essence.” Others adhered more closely to the Arian position. For the next half century, theological battles raged between pro-Nicenes like Athanasius and various theological factions that objected to Nicene orthodoxy.
It was in this context that Semi-Arianism emerged as a mediating position between Arius’ subordinationism and Nicaea’s affirmation of the Son’s consubstantiality. Semi-Arians wanted to affirm the Son as “like” the Father in terms of divine attributes but stop short of saying he was of the same essence. They believed calling the Son “of like substance” preserved his divine status while avoiding what they saw as extreme or unbiblical implications of Nicaea’s homoousian language.
Beliefs and Teachings of Semi-Arianism
Semi-Arians affirmed that the Son was begotten by the Father before creation and that through him all things were made. The Son was eternal, shared moral attributes with the Father, and was to be worshipped. However, they still maintained ontological distinctions between the Father and Son in several key ways:
- The Father alone is unbegotten, without beginning or source. The Son is begotten of the Father, and thus has a beginning point.
- Only the Father possesses divinity in and of himself. The Son possesses divinity by derivation from the Father, not in and of himself.
- The Father and Son are not of exactly the same essence or substance. The Son is like the Father but of a similar substance, not the exact same substance.
- The Son is subordinate to the Father in terms of authority within the Godhead.
In this way, Semi-Arianism affirmed the Son as divine and eternal but not fully co-equal with the Father. He owed his existence to the Father’s begetting and derived his divine attributes from the Father rather than possessing them inherently in himself.
Pro-Nicene theologians argued this made the Son a demigod – divine in name only. Athanasius asserted that an essence only similar to the Father’s was in fact foreign to God’s essence since God’s nature is unique and incommunicable. Any being not partaking of that exact same essence would merely be a creature. Other pro-Nicenes argued that without full ontological equality, the Son’s revelation of God would be inaccurate since the natures would differ.
Semi-Arians supported their beliefs by selectively citing biblical passages that spoke of the Son as subordinate to the Father, being sent by the Father, doing the Father’s will, or receiving authority from the Father (John 6:38, 8:42, 10:36, 14:28; 1 Corinthians 11:3). They argued these indicated the Son was not co-equal or consubstantial with the Father. Of course, pro-Nicenes argued these passages referred to Christ voluntarily functioning in obedience within the economy of salvation rather than speaking of Christ’s ontological subordination as Son from all eternity.
Key Figures and Groups Associated with Semi-Arianism
While there were many individual clergy that held semi-Arian views, a few key figures emerged as leaders and promoters of Semi-Arian theology in the mid-4th century:
- Basil of Ancyra – bishop of Ancyra in Asia Minor. Historians regard him as the main founder and leader of Semi-Arianism. He affirmed the Son was like (homoiousios) the Father but rejected homoousios language.
- Macedonius I – bishop of Constantinople from 342 to 346. He spoke of the Son as a created “instrument” of God and objected to calling the Son “God” preferring the term “Son of God.”
- Eustathius of Sebaste – founder of an ascetic monastic community in Asia Minor. He seems to have affirmed both homoiousian and homoousian positions at different times attempting to reconcile the two parties.
- Eleusius – Macedonius’ successor as bishop of Cyzicus. Along with Basil of Ancyra, he led a homoiousian faction at the Council of Constantinople in 360.
There were also various homoiousian groups and councils held in opposition to Nicaea and pro-Nicene bishops:
- The Council of Sardica (343 AD) demanded that Athanasius be reinstated as bishop and condemned several supporters of Arius.
- The Councils of Arles and Milan (353-355) condemned and exiled pro-Nicene leaders on charges of Sabellianism.
- The Home Synod of Antioch (358 AD) demoted the strongly pro-Nicene Meletius in favor of the homoiousian Euzoius.
- The Council of Constantinople (360 AD) led by Basil of Ancyra affirmed that the Son was like the Father but rejected homoousian language.
- The Pneumatomachians accepted the Homoiousian position but denied the full divinity of the Holy Spirit, seeing the Spirit as a creation of the Son.
Through these councils and competing bishops and theologians, Semi-Arianism gained considerable momentum in the mid-4th century until its eventual rejection at Constantinople in 381.
Rejection of Semi-Arianism
Despite gaining influence for a period, Semi-Arianism was consistently combatted by pro-Nicene theologians and finally condemned at the First Council of Constantinople in 381. Several key factors led to its downfall:
- Persistent opposition from pro-Nicene theologians and bishops like Athanasius, Hilary of Poitiers, and the Cappadocian Fathers.
- The clarity added by the Second Creed of Constantinople in 381 which emphasized that the Son was begotten from the Father’s essence before time, affirming the Son’s consubstantiality.
- The reign of pro-Nicene emperors like Gratian and Theodosius I who favored Nicene Christianity and condemned various heresies.
- The triumph of Nicene Trinitarianism through the work of the Cappadocian Fathers who provided greater philosophical precision to arguments for the Son’s ontological equality.
By condemned Semi-Arian formulations and unambiguously affirming the full deity of Christ, the Council of Constantinople in 381 solidified pro-Nicene orthodoxy as the position of the imperial church. However, Semi-Arianism seems to have persisted for a time among some of the Germanic tribes who had been converted by the missionary Wulfila, a Semi-Arian. But by the end of the 5th century, even these communities had for the most part conformed to Nicene orthodoxy or embraced Arianism instead.
Why Semi-Arianism Was Unbiblical and Needed to be Rejected
While Semi-Arian leaders thought they were securing a middle, scriptural position between Arius and Nicaea, in reality Semi-Arian theology undermined fundamental biblical truths about Christ’s divine nature and salvific work. Scripture reveals that Jesus is the eternally divine Son who reveals the Father perfectly, creates and sustains all things, and redeems humanity. Semi-Arianism compromised or rejected these realities in several ways:
- It denied Christ was really eternal, having been begotten by the Father.
- It made the Son a lesser divine being than the Father.
- It rejected Christ as having the same divine nature as the Father.
- It made Christ’s revelation of the Father inaccurate since their natures differed.
- It undermined the efficacy of Christ’s atoning work if he was not fully divine.
- It threatened proper worship of Christ by denying his co-equality.
Passages like John 1:1-4, 5:17-26; Philippians 2:6-11; Colossians 1:15-20; and Hebrews 1 make it abundantly clear that Jesus Christ eternally shares the divine nature with God, yet as the Son He willingly subordinates himself to carry out God’s plan of redemption. Only the pro-Nicene theology preserved these non-negotiable truths. The church was right to reject any dilution of Christ’s full divinity.
Semi-Arianism Highlighted the Need for Trinitarian Precision
While Semi-Arianism was a doctrinal misstep, it did force church leaders to define Trinitarian theology with greater precision. Questions like how the Son could be eternally generated from the Father yet also co-equal and consubstantial, and how the persons of the Trinity relate to the divine essence needed answering. This required going beyond Scripture into philosophical explanations of ontology and economy. The pro-Nicene theologians were up to the task – men like Athanasius, the Cappadocians, Hilary, Gregory of Nazianzus, and Augustine delved deeply into how the being and relations of the Triune Godhead could logically cohere.
By formulating the doctrine of the Trinity with rigorous philosophical nuance, the Fathers successfully showed why Semi-Arian formulations were inadequate. The specifically philosophical vocabulary they developed – like ousia and hypostasis – became essential for articulating orthodox Trinitarianism. In this sense, Semi-Arianism was an impetus for the church to deepen its understanding of scriptural doctrines through theological reflection guided by Scripture. The Spirit ensured that false teachings like Semi-Arianism were overcome and the truth prevailed.
Semi-Arianism Reminds Us of the Need for Biblical Discernment
As church history repeatedly demonstrates, not all theological opinions claiming Biblical fidelity actually align with Biblical orthodoxy. Semi-Arian leaders thought Scripture backed their theological formulations and their positions seemed reasonable. However, they were wrong. This highlights the need for continual biblical discernment within the church. Doctrinal definitions need to be measured against the yardstick of Scripture. Blind adherence to creeds, traditions, or authorities is inadequate – biblical fidelity is required.
Like the Bereans who examined the Scriptures to see if the Apostles’ teachings were true (Acts 17:11), future generations much test new theological formulations and reexamine traditional doctrines in light of Scripture. The Holy Spirit guides the corporate body of believers into all biblical truth, but we walk by the Spirit through continually submitting to the word of God. Semi-Arianism provides a sober warning not to uncritically accept what merely seems plausible or what has traditionally been believed. We must continually ask what Scripture actually reveals about the marvelous truth of who God is.
Church History Showcases God’s Faithfulness and the Importance of Doctrinal Clarity
While church controversies over issues like Semi-Arianism were painful and divisive, they also gave opportunity for the church’s understanding of Scripture to be honed and clarified. The church collectively wrestled with the biblical texts, discerned between truth and error, and decisively confirmed orthodox Trinitarian theology. God used fallible and sometimes obstinate men to bring the church to greater maturity in the truth.
The story of Semi-Arianism gives us confidence that God does not leave His church in confusion but continues leading believers into deeper knowledge of biblical doctrines. It also reminds us of the vital importance of doctrinal clarity, especially regarding fundamental truths about the nature of God and Christ. Doctrine shapes faith and practice in foundational ways. For the church to remain healthy, it must continually strive to think rightly about God, cling to biblical truth, and reject doctrinal compromise or biblical half-measures.