Lecture 11: Constantine, Theodosius, and the Council of Nicaea

The lecture, section by section

1. The church was never only Roman

   Before Constantine ever converted, Armenia, Georgia, and Ethiopia were Christian nations, and enormous Christian populations lived under Persia, where persecution continued long after Rome's ended. The skeptic's claim that Christianity would have died without Constantine fails on the plain record: the faith was flourishing far beyond his reach. The course centers on Rome because the sources are richest there and because Western Christianity descends from it.

2. The Milvian Bridge

   Roman persecution, rolling in waves from Nero in 64 to its Diocletianic climax around 305, stopped almost overnight. Marching against his rival Maxentius, Constantine reportedly saw a sign of the cross and heard a command to conquer under it; outnumbered, he won, and credited the Christian God. In 313 the Edict of Milan turned hostility into protection, and in 324, having defeated the eastern emperor Licinius, Constantine ruled the whole Roman world. One year later he convened the first general council since Jerusalem, nearly three centuries earlier, a gap explained simply: under persecution the church's leaders could never safely gather.

3. What kind of Christian was Constantine?

   To believers fresh from martyrdom he was a deliverer: opposition abolished, clergy exempted from military service, churches endowed, Sunday given civil standing, his sons educated as Christians. He also christianized the law itself, outlawing crucifixion, the killing of unwanted children, the abuse of slaves, gladiatorial games, and branding of the face, reforms that would flow through Justinian's code into Western law. Yet he delayed baptism to the end of his life, and he killed family members, his own firstborn among them, to secure his throne. Busenitz leaves the verdict where the evidence leaves it: the sincerity of the conversion can be doubted; the scale of the revolution cannot.

4. The cost of the embrace

   Hindsight shows what the fourth century could not: church and state fused, nominal Christianity swelled as pagans were folded in unconverted, and religious liberty vanished for everyone else. Constantine regarded himself, in the old Roman way, as a pontifex maximus over the church, presiding over its councils, and that precedent outlived him: when the western empire fell in 476 and no emperor remained, the bishop of Rome stepped into the vacant role. From this fusion, too, came the medieval equation of heresy with treason, since to defy the church was to defy the state; only the Anabaptists, a millennium later, would argue for separation.

5. Paganism baptized

   Following Calvin's treatise on relics, Busenitz traces how prayers to saints, relics, icons, and votive candles entered the church: an empire baptized without being converted brought its habits along, and the saints simply inherited the pagan gods' portfolios, one saint restoring stolen property like Mercury, another made patron of hunters like Diana, another taking the physicians from Aesculapius. What the church first winked at as temporary, the Middle Ages legalized as tradition.

6. From Constantine to Theodosius

   Constantine moved the capital to Constantinople, the city that would anchor the eastern empire until the Ottomans took it in the mid fifteenth century; historians bracket the Middle Ages between the two falls, Rome in 476 and Constantinople at the end. After Constantine's sons and the brief pagan reaction of Julian the Apostate, Theodosius the Great, the last man to rule the whole empire alone, finished what Constantine began: in February 380 he declared Nicene, trinitarian Christianity the empire's only legitimate religion, convened the second ecumenical council at Constantinople in 381, and turned the machinery of state against Arians, Donatists, and pagans alike. The persecuted church of one century became the persecuting state church of the next.

7. Arius

   A popular presbyter in Alexandria, trained under Lucian of Antioch, Arius publicly opposed his bishop Alexander's teaching that the Son is co-eternal with the Father. His slogan condensed his system: there was once when he was not. Taking begotten to mean created, Arius made the Son the first and highest creature, the instrument through whom God made everything else. A synod of a hundred Egyptian bishops condemned him in 318, but Arius set his doctrine to popular tunes, the controversy spilled into street fights, and the empire's unity itself seemed at stake, which is what finally moved Constantine, indifferent to the doctrine but not to the division, to summon a council.

8. Logic against revelation

   Mark Noll's diagnosis frames the lecture's warning: Arius so prized God's transcendent oneness that he reasoned the Son down to a creature, even accusing Alexander of modalism for holding Father and Son together. Scripture presents two truths, one God, and Father, Son, and Spirit each fully God, and holds them without dissolving either. Arius could not bear the tension and sacrificed one truth to the other, the same move the modalists made in the opposite direction. The lesson for every theologian: never let your logic overrule what God has revealed.

9. One iota of difference

   Three positions met at Nicaea in 325. Heteroousios, of a different essence: the Arian view, championed by Eusebius of Nicomedia. Homoousios, of the same essence: the view of Alexander and of a young deacon named Athanasius, who would spend his life and five exiles defending it. And between them homoiousios, of a similar essence, floated by Eusebius of Caesarea as a compromise wide enough for everyone. The orthodox refused it for one sufficient reason, made plain when the Arians happily embraced it: similar is just a softer word for different. On the nature of God, one letter was the whole gospel.

10. What actually happened at Nicaea

    Roughly 318 bishops attended, some from beyond the empire, with clergy swelling the gathering into the thousands (the number 318 may itself be Eusebius's allusion to Abraham's 318 men in Genesis). The council's task was not to invent a doctrine but to confirm what the church had always believed, and it did: Arius's position was rejected outright, the compromise failed, and the Nicene confession was affirmed by every bishop present except two diehard supporters of Arius. Against the Da Vinci Code's fiction of a mortal Jesus upgraded by Constantine in a relatively close vote, the record answers: Constantine cared only that a decision be made, the bishops affirmed the church's historic faith, and the vote was 316 to 2.

11. The creed itself

    God of God, light of light, very God of very God, begotten, not made, being of one substance with the Father. Begotten here names the Son's uniqueness, not an origin: believers become God's children by adoption, the Son is Son by nature. The creed's anathemas strike every Arian formula by name, there was a time when he was not, of a different essence, a creature. Its central line, who for us men and for our salvation came down, gives Stephen Nichols his book title, and the council of 381 would expand the creed's brief clause on the Holy Spirit into a full confession of his deity. Nicaea did not end Arianism, fifty more years of struggle remained, but it told the truth, and the truth held.

1. Constantine ended the church's suffering and began its entanglement with power. Which danger do you think has proven harder for the church across history, persecution or patronage, and why?

2. Arius and the modalists each dissolved a biblical tension in opposite directions. Where do you feel the pull to simplify a doctrine Scripture leaves in tension, and what guards you?

3. The orthodox refused to sign a creed one letter short of the truth. When is precision in doctrine worth dividing over, and how do you tell those hills from lesser ones?