Emperor or Bishop?

The following excerpt is taken from D. G. Hart’s excellent little book A Student’s Guide to Religious Studies.


As valuable as ecclesiastical councils and creeds and catechisms may be, the writings of individual Christian teachers and theologians have also been decisive in the interpretation of religion’s place in Western society.

Eusebius of Caesarea (260–341), although an Eastern church leader, is significant because of his work as a historian and apologist in the new environment that was created by Christianity’s status as the empire’s official religion. His Ecclesiastical History and Life of Constantine were particularly revealing of the ways in which Christianity could be accommodated for the purposes of public life.

Eusebius’s “Divine Will”

Eusebius had a variety of aims in writing the history of the church in the manner he did, some of which reflected his own position in the theological controversies that had led Constantine to call the Council of Nicea. But one central theme in Eusebius’s historical writings is a conception of divine providence in which he interprets Constantine’s conversion and recognition of the church as a crucial development in its success and prosperity.

For Eusebius, the emergence of Christianity as the faith of the empire is the culmination of salvation history. In turn, he treats the rule of Constantine as the fulfillment of divine promise, thus identifying political rule with divine will. The emperor’s function as the head of the church would be a feature that distinguished the Eastern church from its Western counterpart, a distinction not fully realized until the break between the Eastern (Orthodox) and Western (Roman Catholic) churches in 1054.

By making Christianity the established religion of the empire, Constantine, along with Eusebius’s justification of his action, created a tension with which Christians have had to deal since the fourth century—namely, the degree to which church affairs and civil society are or ought to be separate, and, by extension, whether the emperor or the bishop is the ultimate authority in the ecclesiastical realm.

Augustine’s “Two Cities”

Part of what makes Augustine of Hippo (354–430) worthy of study are his own struggles with this question. One of the West’s most insightful and fruitful minds, Augustine’s moving account of his conversion to Christianity in The Confessions (400) has served as an important text for modern interpretations of the formation of the self.

But perhaps of more lasting consequence has been his consideration of the significance of Rome’s fall (410) for the history of the church and Western civilization. In The City of God, begun in 413 and not completed until thirteen years later, the North African bishop developed the idea of “two cities,” the city of man and the city of God.

Contrary both to imperial theologians like Eusebius, who saw the hand of the divine in the political history of civilizations, and to the church’s opponents who blamed Rome’s fall on Christianity, Augustine avoided either demonizing or divinizing the political realm. The city of God is that polity where true piety rules and is distinct from the city of man, where civil law and imperial authority govern. These cities were not necessarily at odds, but neither could they be identified with one another as Eusebius had believed.

Augustine did not abandon the high view of divine providence that was espoused by imperial theologians. He argued that God still controlled the affairs of Rome and its civilization even in the midst of adversity. At the same time, he advised that Christian virtues were clearly advantageous to the prosperity of the city of man. But whatever peace and prosperity the empire displayed, he added, were only types or foreshadowings of the heavenly city, whose vindication awaited the end of human history.

By distinguishing the ultimate ends of religion from the temporal ones of empire, Augustine set the terms that would allow future Christians, and others, to navigate the tension between religious and political authority created by Constantine’s conversion.


Darryl G. Hart is a religious and social historian. Hart is Distinguished Associate Professor of History at Hillsdale College in Hillsdale, Michigan.

Image by Iam Os via Unsplash.

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