A Short History of the Middle Ages Fourth Edition

church council, the Council of Nicaea, in 325. There the assembled bishops

hammered out some of the canon law and doctrines of the Christian church.

After Constantine, it was simply a matter of time before most people considered

it both good and expedient to convert. Though several emperors espoused

“heretical”—unacceptable—forms of Christianity, and one (Julian, the “Apostate”)

professed paganism, the die had been cast. In a series of laws starting in 380 with the

Edict of Thessalonica and continuing throughout his reign, Emperor Theodosius I

(r.379–395) declared that the form of Christianity determined at the Council of

Nicaea applied to all Romans, and he outlawed all the old public and private cults.

Christianity was now the official religion of the Roman Empire. In some places,

Christian mobs took to smashing local pagan temples. In these ways—via law,

coercion, and conviction—a fragile religion hailing from one of the most backward of

the provinces triumphed everywhere in the Roman world.

But “Christianity” was not simply one thing. In North Africa, Donatists—who

considered themselves purer than other Christians because they had not backpedaled

during the period of persecutions—fought bitterly with Catholics all through the

fourth century, willingly killing and dying so that “the lapsed” might not “hold

ecclesiastical office again.”^2 As paganism gave way, Christian disagreements came to

the fore: what was the nature of God? where were God and the sacred to be found?

how did God relate to humanity? In the fourth and fifth centuries, Christians fought

with each other ever more vehemently over doctrine and over the location of the

holy.

Doctrine

The so-called “Church Fathers” were the victors in the battles over doctrine. Already

in Constantine’s day, Saint Athanasius (c.295–373)—then secretary to the bishop of

Alexandria, later bishop there himself—had led the challenge against the beliefs of the

Christians next door. He called them “Arians,” rather than Christians, after the priest

Arius (250–336), another Alexandrian and a competing focus of local loyalties.

Athanasius promoted his views at the Council of Nicaea (325) and won. It is because

of this that he is the orthodox catholic “Father” and Arius is the “heretic.” For both

Athanasius and Arius, God was triune, that is, three persons in one: the Father, the

Son, and the Holy Spirit. Their debate was about the nature of these persons. For the

Arians, the Father was pure Godhead while the Son (Christ) was created. Christ was,

therefore, flesh though not quite flesh, neither purely human nor purely divine, but

mediating between the two. To Athanasius and the assembled bishops at Nicaea, this