E1: A Core to (Just) War: Diverse Theories in a Common Tradition

All great civilizations—and probably every minor one—have pondered, if not formalized, an ethics of war, including consideration of when it is right to fight and how one ought to fight once the fight has been engaged. The just war tradition comprises a multimillennial-long collection of reflection on the ethics of war that has emerged out of the West’s Greco-Roman and Hebraic moral inheritance. This post offers a short historical overview of the tradition’s development.

Development is the appropriate word, the just war tradition didn’t simply spring forth ex nihilo. Certainly, we can point to just war ideas in early Jewish thought, ancient Greek philosophers such as Aristotle and Cicero, and, of course, in the Christian scriptures and early theologians like Augustine (354-430)—whose emphasis on Christian moral and political responsibility as manifestations of Christian love will reside at the core of this developing tradition. But the forging of a systematic, consolidated conception of just war as we would recognize it today wouldn’t begin to happen until around the middle of the 12th century.

This occurred with Gratian’s (1101-1159) Decretum and two generations of his successors, the Decretists and the Decretalists. Together they incorporated Christian thought; practical experiences drawn from governing and warfare; and a retrieval and ressourcement of Roman law, which included natural law and ius gentium, or the law applicable not only to Roman citizens but held in common by all peoples throughout the empire. In the latter bit of the 13th Century, all of this work would be summarized and pulled into a theological framework by Thomas Aquinas (ca. 1125-1274). This is a watershed moment in the development of just war as a tradition for Thomas will become arguably the key figure for engaging just war in its specifically Christian form. I’ll just assert this for now and will leave it to a future essay to make the case.

For now, let me just point to one significant point. In his reflection on the ethics of war, Thomas followed Augustine’s emphasis on love by placing his own discussion of just war in the Summa Theologica in the midst of his treatment of caritas or charity. Not incidentally, Thomas might also have taken his cue from the Apostle Paul, who, in his Epistle to the Romans (12:9), implores the Christian to “love without hypocrisy,” and, in the immediate verses following, explains what this means. Later (13:10), he proclaims that “Love does no wrong to the neighbor.” In between these points he discusses human government and affirms that God has ordained government to use “the sword” to curb wrong-doing. In both this Pauline and Thomistic bookending, then, deliberation on the use of force occurs in the midst of a discussion of love. Ever since, love will be at core of Christian reflection on the use of force. For this reason, connections between love and war will feature both directly and indirectly throughout this series.

Following Thomas in the later Middle Ages, particularly during the Hundred Years War, the theological and canonical dimensions of just war would be further elaborated by the incorporation of ideas, customs, and practices from the Medieval conception of chivalry. I’ve written and spoken on C.S. Lewis and chivalry as it illuminates just war tradition. You can find both an essay and audio-file here.

Further on, Martin Luther (1483-1546) departed from certain traditional tenets of the just war tradition, even as he improved the tradition in other ways. Ever the bombastic iconoclast, Luther tended “to dispense with traditional subtleties and distinctions” thereby giving an account of war with considerablye less nuance than earlier writers. Most pointedly, Luther’s treatment of right intention lacks any reference to love for the enemy and one finds few restrictions in his discussion of the ethics of how one actually fights once conflict is engaged. Luther didn’t dispense entirely with the idea that charity was a necessary motivation for fighting, but the focus of this love was on the innocent neighbors who needed rescue and to live in a world governed in an orderly way. How this is a work of love is seen in Luther’s stark image of a world without strong ruling authorities. He asks us to imagine herding together wolves, lions, eagles, and sheep into a single pen, letting them mix freely and bidding them to feed and live peaceably. In such a scenario, good will and the gospel alone would be insufficient. Without enforced security, the strong would simply prey upon the weak. For these reasons, Christians should seek out governing authority if they have the necessary skills whether as court official, judge, or even hangman.

John Calvin (1509-1564) marked a substantive return to earlier emphases, illustrated by his grounding of the coercive powers of the state in natural law, thereby linking civil and moral law in the pursuit of justice. Doing so gestures brings us again to Augustine and his distinction between internal dispositions and external acts, resulting in our ability to both love and kill the enemy as we distinguish between the sinner and the sin. Unlike, arguably, Luther, Augustine did see just war as a matter the requirements of justice overruling the requirements of love and saw no necessary contradiction between a Christian engaging in warfare and loving the enemy. Like a parent who disciplines an errant and recalcitrant child with a “benevolent harshness”, one can punish an enemy while having the enemy’s good in mind.

The primarily Christian theological content of just war tradition had begun to wane by the 17th century. While early-modern just war thinkers like the Spanish neo-scholastics Francisco de Vitoria (1492-1546) and Francisco Suárez (1548-1617) and the Dutch jurist Hugo Grotius (1583-1645) were theologians who used Christian scripture, texts, and arguments, they each also attempted to present just war principles on the more universal ground of natural law. In doing so, they developed arguments both more comprehensive as well as more widely applicable beyond the Christian West. Grotius, in particular, also contributed significantly to the deeper development of criteria regarding the moral conduct of war.

In the 1960s, however, Paul Ramsey (1913-88) pioneered a revival of specifically Christian, Augustinian just war thinking, which has been kept alive since in the work of thinkers such as Oliver O’Donovan (1945- ), Nigel Biggar (1955- ), me, and many of the writers associated with Providence.

This brief overview runs the risk of oversimplification. Among much else, we ought to be careful to observe that it can sometimes be problematic to speak of, simply, the just war tradition. Here the definite article is too definitive and risks eliding the diverse accounts of just war that have emerged over the more than 1,500 years of scholarship, most especially in the modern era. We need to be careful to distinguish varying points of emphasis, to acknowledge disagreement, and to take care to discern when the same terms are being used in different ways. This latter point reminds us that when the variance is significant enough, we need to be able to say that something has ceased to be a part of just war thinking and has, rather, become something else. As Jim Johnson has suggested,

There have been many particular just war theories, but insofar as they hang together with sufficient commonalty, they all belong to just war tradition. At the same time, though, a tradition needs sufficient commonalty, a coherence of basic conceptions and agreements as to meaning and purpose. In this, a moral tradition like that of just war is like language: speakers may differ broadly as to vocabulary, pronunciation, syntax, intonation, and all the other features that make it possible to speak, say, of British English and American English while recognizing both as English. Yet at some point a local version of a language may become so different, so unintelligible to persons from different localities that it has to be recognized as a different language, as in the evolution of distinct Romance languages from a common Latin source. I

This is why I’ll be at pains to speak of just war tradition, rather than just war theory. The tradition is made up of various theories held together by sufficient “family resemblance” as to be intelligibly related. The theory from which I position myself—and this series—within the wider just war tradition will be that of Christian realism. The overview I have presented above, roughly, follows the contours of the Christian realist mode of just war thinking. Longtime readers of Providence might think this focus on Christian realism means, therefore, that what I will expound will be Niebuhrian. This is not quite right. As careful longtime readers of Providence know, I have my beefs with Niebuhr’s brand of realism. I’ll expand on this, too, in a future essay. Hint: I don’t think it’s theologically realistic. But I will show why that matters.

Next time, I will explore just war’s basic moral logic.

Further Historical Reading:

Anything by James Turner Johnson. For a brief, accessible essay, you can’t do better than this: Just War As It Was and Is.

See also my chapter on “Just War” in Protestant Social Teaching