When Our World Became Christian

A year after the battle, in 313, Constantine and his eastern colleague Licinius issued what history calls the Edict of Milan, extending toleration to Christians and restoring property that had been confiscated during the persecutions. It is worth being precise about what this was and was not. It did not make Christianity the state religion. It did not outlaw the old gods. It legalized a faith and returned what had been taken. The empire remained, in its overwhelming bulk, pagan — its temples open, its festivals running, its priesthoods intact.

Here is the tension Veyne draws out: Constantine was, by his own lights, a believer, but he governed a world that was not. He could not simply convert his subjects by decree, and he did not try to. He kept the traditional titles, tolerated the old cults, and moved carefully. What he could do was pour the resources of the state toward the church he now favored — building basilicas, granting the clergy legal privileges and exemptions, handing the bishops a status they had never dreamed of. Favor flowed downhill from the throne, and where the emperor's favor went, ambition and prestige followed.

The church Constantine attached himself to was not the smooth institution of later centuries. It was young, argumentative, and dangerously unsure what it actually believed. No sooner had the emperor thrown his weight behind Christianity than he discovered that Christians could not agree among themselves — and that their disagreements now threatened the peace of the state he ran. A quarrel among theologians had become, overnight, an imperial problem.

The great crisis was the dispute over Arius, a priest from Alexandria who taught that Christ, the Son, was not fully equal to God the Father but was in some sense created by him. The question sounds abstract; the stakes were not. It split cities and provinces. Constantine, exasperated, summoned bishops from across the empire to Nicaea in 325 for the first great ecumenical council, and he presided over it himself — a layman, and only recently baptized in intent, sitting at the head of the church's deliberations. The council produced the creed that condemned Arius and affirmed the Son as of one substance with the Father.

Step back from the battle and the councils, and the striking thing is the disproportion. A single man's conviction, formed somewhere between a dream and a victory, set in motion a change that neither he nor anyone else designed. Constantine did not plan a Christian Europe. He did not outlaw the old gods; that came later, under successors, culminating near the end of the fourth century when Theodosius made Christianity the official religion and moved against paganism in earnest. Constantine only tilted the field. But once the most powerful office on earth leaned toward one god, the whole slope of society began to run in that direction.

Veyne's deeper argument is about how belief and power interact when they meet in the same person. We tend to sort motives into clean bins — either Constantine believed, or he calculated. The book's whole force is in refusing that split. He believed and he ruled, and belief in the mind of a ruler is never a purely private thing, because a ruler's convictions come equipped with treasuries, armies, and the power to make careers. A conviction that would have died with a farmer became, in an emperor, the seed of a civilization's religion.

The story that begins at the Milvian Bridge does not end with a converted people. It ends with a converted throne, and a society reorganizing itself around it over the following century. Constantine died in 337, baptized only on his deathbed, having spent his reign as a Christian emperor of a still largely pagan empire — favoring the church, funding it, refereeing its quarrels, but never quite forcing the world into the shape of his own conviction. The forcing came later. What he supplied was the tilt, and the leverage that made the tilt decisive.