When teaching the history of the field of International Relations (IR), scholars tend to start with the classical author of The Peloponnesian War, Thucydides, then skip immediately to the early modern political theorists Machiavelli and Hobbes. In the process, they ignore the entire medieval period and, therefore, the rich history of Catholic international thought that flourished in that period. There are, of course, exceptions to this rule. Reinhold Neibuhr, for example, famously drew on the works of Saint Augustine as he helped launch the school of international relations theory known as Realism in the mid-20th century. But this is the exception. For the most part, the great Catholic international thinkers of the Middle Ages are simply erased from history. This is my humble effort to undo that grave error.
Augustine: Human Nature and International Relations
Augustine of Hippo, admittedly a figure of late antiquity but crucially important to understanding medieval political thought, is typically introduced to students as the founder of Just War theory. While this is certainly an apt description of the Doctor of Grace, it does not fully capture his contribution to the Realist tradition of international thought. As Reinhold Niebuhr and other 20th century Realists have pointed out, Augustine’s primary contribution is his insight that politics are driven by the lust for power (libido dominandi) and that this results in international relations that inherently conflictual. As Augustine put it: “The dispute between Cain and Abel proved that there is enmity between the two cities themselves, the City of God and the city of man. Accordingly, there are battles of wicked against wicked. There are also battles of wicked against good and good against wicked. In the 20th century, this became known as the “first image” explanation for war – the view that wars result from human nature and are, therefore, an enduring element of political life. And this leads to his second insight, that the prospects for political progress, and especially for political perfection, are vanishingly small. Humanity is fallen, and “insofar as men are sinful, the threat of war hangs over them, and hang over them it will until the return of Christ.”