A helpful primer from James K. A. Smith, who reminds us that Augustine’s “earthly city” begins with the Fall, not creation:

The phrase comes down to us from Augustine’s magisterial work of cultural criticism, The City of God (civitas Dei, completed around 427 A.D.). In this work, Augustine distinguishes the “City of God” from what he variously describes as “the city of this world,” the “earthly city,” and the City of Man. These two cities or societies or “peoples” are marked by the standards by which they live: the earthly city lives by the standard of the flesh, whereas the City of God lives by the Spirit (14.1-4). What ultimately distinguishes the two are their loves: “We see then that the two cities were created by two kinds of love: the earthly city was created by self-love reaching the point of contempt for God, the Heavenly City by the love of God carried as far as contempt of self” (14.28).

For Augustine, then, the earthly city begins with the Fall, not with creation. The earthly city is not coincident with creation; it originates with sin. This is why Augustine sets the City of God in opposition to the earthly city: they are defined and animated by fundamentally different loves. So the earthly city should not be confused with the merely “temporal” city or the material world. It is not identical to the territory of creation; rather, for Augustine, the earthly city is a systemic—and disordered—configuration of creaturely life. However, this does not mean that Augustine cedes material, cultural, creaturely life entirely to the evil one. The City of God is not just otherworldly: the City of God is that “society” of people—that civitas—who are called to embody a foretaste of the social and cultural life that God desires for this world.

Augustine doesn’t invoke the earthly city in order to motivate Christians to care about this-worldly cultural life. His theology of creation already does that. The analysis of the earthly city is instead cautionary, pressing Christians to recognize that cultural systems are often fundamentally dis-ordered, in need of both resistance and reordering by Christian labor in all streams of culture. And as we can see from his letters, Augustine involved himself in such work. There you’ll find the bishop invested in the concrete realities of politics and civic life.

Augustine doesn’t use the term “earthly city” to carve up reality into a “heavenly” second story and an “earthly” first floor. No, both the earthly city and the City of God are rival visions of heaven and earth. So the “earthly city” is more like Babylon than the Garden. But even this fundamental antithesis doesn’t give us permission to retreat into holy huddles or simply castigate the earthly city.

You can read the whole post here.