Two cities and earthly justice: are earthly kingdoms 'without true justice nothing but great bands of robbers,' and is genuine justice possible only where God receives his due?

Augustine of Hippo, answered from the texts and cited to the page.

The position in brief

Two cities have been formed by two loves: the heavenly city by love of God to the contempt of self, the earthly city by love of self to the contempt of God (City of God XIV.28).¹² The two cities are intermingled throughout history; no political form is the civitas Dei on earth, no political form is wholly the civitas terrena, and Christians live as pilgrims through the saeculum — the time between Christ's ascension and the eschaton.

Earthly polities have real but limited value: they secure the relative peace that allows the city of God to make its pilgrimage. True justice — vera iustitia — requires giving God his due (pietas), and Cicero's definition of the commonwealth as a "concord based on justice" entails, when followed honestly, that pagan Rome was never truly a commonwealth at all. Remota itaque iustitia quid sunt regna nisi magna latrocinia? — without justice, what are kingdoms but great bands of robbers?³⁴

Sources

1. For who will dare to believe or say that it was not in God's power to prevent both angels and men from sinning? But God preferred to leave this in their power, and thus to show both what evil could be wrought by their pride, and what good by His grace. Ps. cxi. 2. Chapter 28.--Of the Nature of the Two Cities, the Earthly and the Heavenly.

   The City of God, pp. 744–746

2. About these ends of both we must next treat. Ps. lxxii. 8. Acts xvii. 30, 31. Isa. ii. 3. Luke xxiv. 47. Book XIX. Argument--In this book the end of the two cities, the earthly and the heavenly, is discussed.

   The City of God, pp. 1022–1023

3. Now, therefore, I think fit to do what I passed by, and show, so far as seems necessary, how that other city ran its course from the times of Abraham, so that attentive readers may compare the two. > Chapter 2.--Of the Kings and Times of the Earthly City > Which Were Synchronous with the Times of the Saints, Reckoning from the Rise of Abraham.

   The City of God, pp. 936–937

4. Thus we gather the very day with which that year began, namely, that on which the Holy Spirit was sent, that is, during the ides of May. And, on counting the consuls, the three hundred and sixty-five years are found completed on the same ides in the consulate of Honorius and Eutychianus.

   The City of God, pp. 1020–1022

Where the argument is made

• City of God (De Civitate Dei, 413-426), all 22 books, especially Book IV (true justice and Cicero's commonwealth), Book XIV (the two loves), Book XIX (the two cities, the peace of expediency, true peace), and Book XXII (the resurrection and the final separation)
• Letter 138 to Marcellinus (411-412) on the political consequences of Christianity
• Letter 189 to Boniface on Christian soldiers

How the argument was received

Defended in the City of God across 413-426. The two-cities framework became foundational to medieval political theology and the conceptual ancestor of the church-state distinction. Modern political-theological reception is divided: Markus's Saeculum (1970) is the dominant deflationary reading (the two cities intermingled in the saeculum; politics has its own legitimate sphere); Milbank's Theology and Social Theory (1990) argues for a more thoroughgoing theological politics in which the secular is a Christian-modern invention; secular political philosophy reads the relativization of pagan polities as theocratic and finds the position politically dangerous.