Part Four
Our mindes must he so confirmed and conformed, that we may bee at rest in troubles, and have peace even in the midst of warre.
—Justus Lipsius, Of Constancie (trans. Sir John Stradling, 1584)
Chapter Eleven
Early Christianity
Soon after Vegetius wrote, the western empire collapsed. For a thousand years to come, warfare in western Europe would be interpreted by theologians and jurists: Vegetius, Sallust, and other Latin secular writers never ceased to be read, but those who read and commented on them were mostly monks and clerics, whose basic assumptions about warfare came from the church fathers. Of the three ancient traditions surveyed in this book, the moral had virtually swallowed the realistic and the constitutional. Nevertheless, there was more continuity in the classical legacy than we often think, for Christian thought about warfare was totally dominated by a just war doctrine1 that was itself of pagan Greco-Roman origin.
Christians had no choice but to take over the classical legacy in this area because it was impossible to extract any coherent theory of warfare from the sacred books of Christianity. This literature contains two absolutely contradictory traditions. There is the Old Testament tradition of the War of Yahweh, which has been described in Chapter 2. The historical and legal books portrayed the early Hebrews going to war at the express command of God, who ordered them to exterminate all the pagans of the Holy Land and reduce to servitude all living outside it. Whether the real early Hebrews ever did either is open to doubt, but few early Christians doubted it. The New Testament, by contrast, taught a doctrine of extreme nonviolence. It is true that the New Testament also taught obedience to worldly authority, but it offered no obvious way to reconcile the two principles. Jesus said to resist not evil but also to render unto Caesar that which is Caesar’s; Paul told the Christians of Rome to leave vengeance to the Lord but also to honor the powers that be. Still, the main impression left by the passages on war in the New Testament is as irenic as the impression left by the Old is sanguinary. During the early centuries, many Christians shunned military service as sinful , many apologists condemned the Roman empire and all its works, and none saw any useful political model in the holy wars of the Old Testament, which were assigned to a former dispensation or sometimes allegorized out of existence.
The Byzantine Tradition
When the church made its alliance with the empire in the fourth century A.D., this contradictory heritage provided no way to explain the new relationship. The Judaic side of it contained no relevant theory of statecraft; the Christian side contained no statecraft at all. Constantine’s bishops perforce adopted, with greater or lesser hesitation, the traditional Roman ideas about warfare and imperialism surveyed in previous chapters—aided, of course, by the fact that the Roman tradition had always been sententiously ethical and religious in tone. The tradition was now given a Christian flavor, which sometimes smacked of the New Testament and sometimes more of the Old. The Christian versions of just war have always tended toward either one or the other.
Among the patristic writers of the Christian empire, the Old Testament influence generally predominates over the New. The emperor was regarded as deputy of God and protector of the faith. The concept of the universal empire was revived and took on a new dimension, for the Roman people were now also the people of Christ, and the universal claims of Rome merged with the equally universal claims of the church. The barbarian enemies of Rome were conflated with the pagan and heretical enemies of the church, and military service to protect the Christian empire from both became a pious Christian duty. The New Testament precepts of nonviolence were interpreted as referring to an inner disposition and in their literal sense were thought to be binding only on the clergy and monks. Some bishops mingled the pagan rhetoric of righteous and triumphal imperialism with Old Testament language about holy war. St. Ambrose’s On Duties, an adaptation of Cicero’s On Duties for Christian clergy, did not omit military duties, though acknowledging that some would find this unfit for priests. St. Ambrose pointed out that Old Testament heroes like Joshua, Samson, and David had won glory in war, and he even suggested that what Cicero, Panaetius, Aristotle, and other pagans had said about this subject had been borrowed from the Hebrew Scriptures (.Duties 1.35; Christians liked to claim that everything that was of any value in the pagan classics had been stolen from the Scriptures, which they imagined to be of vastly greater antiquity).
For courage, which in war preserves one’s country from the barbarians, or at home defends the weak, or comrades from robbers, is full of justice. (1.27.129)
Here, then [in the example of the Maccabees] is fortitude in war, which bears no light impress of what is virtuous and seemly upon it, for it prefers death to slavery and disgrace. (1.41.211 [trans. H. de Romestin])
In the Byzantine empire the tradition of triumphal rulership continued throughout the Middle Ages. But its imagery did not begin to appear in the Greek liturgy until the seventh century, a tardiness that suggests that even at Constantinople there persisted a sense of anomaly about praising warfare in Christian services.2
Augustine
Western Christianity became dominated by a different tradition. The early collapse of the western empire did not allow Byzantine triumphal rulership to take root; and St. Augustine, who wrote his City of God to explain the sack of Rome in A.D. 410, deliberately set the Latin churches on a separate track. Throughout the Middle Ages, the writings of Augustine remained the most important influence on western European thinking about warfare.3 His concepts and imagery reflect the Gospels far more than the Books of Joshua and Maccabees. He firmly rejected the ideals of triumphal rulership then gaining acceptance in the East and refused to identify the civitas Dei, the invisible community of the saved, or even the visible organization of the church, with the Roman empire or with any earthly city.
In A.D. 382, the Christian emperor Gratian had the ancient statue of the goddess Victory removed from the Roman Senate, and the defenders of paganism claimed this resulted in the sack of 410. In the City of God, Augustine asks satirically why they did not also have a god named Empire, and continues with a sustained assault on the Roman tradition of just imperialism.
I would … have our adversaries consider the possibility that to rejoice in the extent of empire is not a characteristic of good men. The increase of empire was assisted by the wickedness of those against whom just wars were waged. The empire would have been small indeed, if neighbouring peoples had been peaceable, had always acted with justice, and had never provoked attack by any wrong-doing. In that case, human affairs would have been in a happier state; all kingdoms would have been small and would have rejoiced in concord with their neighbours. There would have been a multitude of kingdoms in the world, as there are a multitude of homes in our cities. To make war and extend the realm by crushing other peoples, is good fortune in the eyes of the wicked; to the good, it is stern necessity. But since it would be worse if the unjust were to lord it over the just, this stern necessity may be called good fortune without impropriety. Yet there can be no shadow of doubt that it is greater good fortune to have a good neighbour and live in peace with him than to subdue a bad neighbour when he makes war. It is a wicked prayer to ask to have someone to hate or to fear, so that he may be someone to conquer.
So if it was by waging wars that were just, not impious and unjust, that the Romans were able to acquire so vast an empire, surely they should worship the Injustice of others as a kind of goddess? For we observe how much help “she” has given toward the extension of the Empire by making others wrong-doers, so that the Romans should have enemies to fight in a just cause and so increase Rome’s power … With the support of those two goddesses, “Foreign Injustice” and Victory, the Empire grew, even when Jupiter took a holiday. (City of God 4.15 [trans. Henry Bettenson])
Augustine admits that Rome brought universal peace and fellowship,
but think of the cost of this achievement! Consider the scale of those wars, with all that slaughter of human beings, all the human blood that was shed! … But the wise man, they say, will wage just wars. Surely, if he remembers that he is a human being, he will lament the fact that he is faced with the necessity of waging just wars; for if they were not just, he would not have to engage in them, and consequently there would be no wars for a wise man. For it is the injustice of the opposing side that lays on the wise man the duty of waging wars; and this injustice is surely to be deplored by a human being, since it is the injustice of human beings, even though no necessity for war should arise from it. (19.7 [trans. Bettenson])
No Stoic had seen so clearly the fundamental hypocrisy of Roman imperialism, its unholy eagerness to exploit the “injustices” of foreigners. Yet Augustine never questions that just wars must be fought, so long as they are fought in the spirit he describes in this quotation, or that the earthly peace they bring is anything but good, even if it is not heavenly peace. War, like other social and political evils, is a punishment for original sin, but it is also a restraint upon sin, the instrument through which the just curb the wicked. Behind it all there is God’s providential plan, directing the rise and fall of empires, but this plan is mysterious to us; he says we cannot tell why God allowed the fall of the Christian Roman Empire or any other state, and it is presumptuous to think that we can see the unfolding of the divine plan in the rise of any state. This Augustinian historical vision is reminiscent in some ways of the cosmic law of Herodotus, except that the Herodotean vision, however pessimistic, did inspire an interest in the rise and fall of states, which to Augustine has become a repetitious and unimportant phenomenon whose study can only distract us from contemplation of that heavenly city that is our true home.
The Augustinian attitude toward warfare is therefore deeply pessimistic and unwilling to assign positive value to it. The paradoxical result of this pessimism is that it made Augustine’s view of just war more vindicative than the traditional pagan view. To Augustine, a just war is permissible only if carried out for motives of charity. There is an obligation to go to war to resist any kind of immorality, and the insistence that we can only fight for the purest of motives tends to remove restraint. Those who fight for love may be more ruthless than those who fight for glory or land. Augustine said nothing to suggest that a just war should not be offensive, so long as our motives are pure; and he provided an explicit justification for offensive war in his commentary on Numbers 21.21-25, where the Israelites start war simply because their neighbors would not give them right of passage through their country, proving that denial of any right is a just cause (Questions on the Heptateuch 4.44). Augustine defined a just war simply as a war to avenge injuries (.Heptateuch 6.10), a definition that was to enter the medieval canon law and become the classic statement of this view.
It should be emphasized, however, that this is a peculiarly Augustinian brand of moral vindication: Warfare, in this perspective, is undertaken to avenge the whole moral order, but there is everywhere in Augustine’s works so much awareness of the ineffability of God’s plan that it is difficult to identify just warfare with any particular state or ruler, as the pagan Romans and the Christian Byzantines did in their different ways. Also, the moral criteria for a just war seem so exacting that they raise the question of whether there had ever been one, apart from the wars of Yahweh in the Old Testament— which Augustine thought were simply just wars, not particularly “holy” wars, differing from other just wars only in that we happen to know those were just by revelation. With those exceptions in the distant past, Augustine provided ample reasons to doubt the justice of any war, to those who read him carefully. Isolated quotations from Augustine about the vindicativeness of war could have the opposite effect.
The Medieval Just War Doctrine4
The continuous history of just war doctrine began about 1140 with the Decretum of Gratian, the basic compilation of canon law (the laws of the church), which discusses the morality of warfare in its Causa 23. Gratian quoted there the definitions of a just war by Cicero (through Isidore of Seville) and by Augustine: The first is Roman and emphasizes the need for formal declaration; the second is Christian and emphasizes vindicative purpose, but it is a matter of emphasis. Gratian synthesized the two in his comment on these passages: “A just war is waged by an authoritative edict to avenge injuries” (Causa 23, quaestio 2, dictum post canonum 2 [trans. F. H. Russell]).
Commentaries on this section by the canon lawyers of the later twelfth and thirteenth centuries stayed within Gratian’s definition and generally followed his lines of interpretation; and the theologians followed the lead of the canonists. (Discussion of warfare was dominated by canon lawyers throughout the Middle Ages because the basic text of the canon law, Gratian’s Decretum, included a section on warfare, whereas the texts studied by theologians passed over the problem; hence the legalistic tone of this discussion.) Today the best-known medieval treatment of the ethics of war is that of Thomas Aquinas in the Summa Theologiae (2.2. quaestio 40), who laid down three requirements for a just war: It must have right cause, right intention, and right authority. The major medieval contributions to the theory may be conveniently divided into these three areas.
Not much of substance was added to the ancient theory of just cause. Medieval discussions commonly recognize the causes mentioned in Gratian: A just war must repel or avenge injuries or recover goods. All seem to assume a just war may take the offensive, citing Augustine on the Israelites5 right of passage in Numbers 21. But it is significant that both jurists and theologians pay little attention to the crusade. Gratian did not even mention crusades. The papal bulls authorizing crusades were not included in the collections of papal decretals that were added to Gratian. When canonists did discuss crusading, they generally defined it as simply a special type of just war: the just warfare of the church, declared by the pope for the protection of the Christian faith, subject to the same rules as any other just war. Some said crusades must be confined to the Holy Land, for they were intended to recover the lands of the church. In any case, they had to be justified as responses to some injury to the church committed by infidels. As usual, the concept of injury was flexible. For example, it could include attempts to interfere with the work of Christian missionaries. Still, few thought infidels could be attacked simply for their infidelity. To the end of the Middle Ages, Christian thought continued to balk at the notion of a genuinely holy war, fought for religious reasons alone, without secular justification.
The problem of right intentions produced the most lasting medieval contribution to just war theory. The Augustinian principle that wars must be fought in a spirit of charity, without hatred for the enemy, compelled the canonists and theologians to pay far more attention to the jus in hello, the rules for the conduct of warfare, than had ever been done in antiquity. They focused on noncombatant immunity. By the thirteenth century, the canon law recognized a lengthy list of persons who were supposed to be exempt from violence in wartime—clergy, monks, women, peasants, merchants, indeed everyone but the fighting class of knights and soldiers. Such concerns were unknown in the classical world; they constitute the main specifically Christian and Augustinian element in the modern theory of just warfare. Modern attempts to limit warfare have generally followed the same strategy of making clear distinctions between combatants and noncombatants and insisting on the immunity of the latter, though in the twentieth century this distinction has become increasingly difficult to enforce.
As for the problem of right authority, it was peculiar to the Middle Ages, and discussion of it then has little relevance to any time before or since. No one in antiquity gave much thought to the question of who was authorized to declare a war because the answer was nearly always obvious. But it was not obvious over much of western Europe in the Middle Ages, where authority was fragmented within a confusing network of imperial, royal, clerical, and feudal jurisdictions, so the canonists found themselves spending much time on the problem of who possessed the authority to declare a just war. Until around the year 1250, many said that only the Holy Roman Emperor could declare a just war, except for a crusade, which had to be declared by the pope. After that time, it was generally conceded that just wars could be proclaimed by any prince who was supreme in his own kingdom. But another category of permissible warfare was also recognized: the war of self-defense. It was a principle of Roman law that anyone had the right to repel force with force. This right applied only to private persons, but the canonists applied it to warfare and recognized that any knight could rightfully defend himself if attacked. This was distinct from the just war, which required a higher authority, and it was a strictly circumscribed right: The attack had to come first, the response had to be immediate, the violence used had to be proportionate to the danger. The unintended effect was to introduce into the just war tradition for the first time a clear definition of a purely defensive type of warfare distinct from vindicative just war in the traditional sense.
By the later Middle Ages, there was general agreement in western Europe on the rules of warfare. A synthesis had developed that was essentially based on the work of twelfth– and thirteenth-century canonists and theologians. It incorporated the principles just described but added elements from the revived study of Roman law, the revived study of Aristotle, and the knightly code of chivalry.5 The synthesis was propagated by works like The Tree of Battles by the monk Honoré Bovet (1387) and The Book of Deeds of Arms and of Chivalry by the poetess Christine de Pisan (1410), both written in French for a lay and knightly audience. It was universally recognized that any prince had the right to wage just wars, but there was strong emphasis on the obligation of every prince to respect the common law of Christendom, to never pick wars for selfish or frivolous reasons, and to conduct wars in a spirit of Christian love and knightly chivalry, paying particular attention to the immunity of women and other noncombatants. This common law of Christendom was an amalgam of all the elements mentioned earlier and could be described in different ways: Theologians and canonists of the old school spoke of it as a divine law revealed in Scripture, theologians influenced more by Aristotle than Augustine preferred to call it a natural law imposed by human reason, and the glossators on the Roman law called it the jus gentium, the law of nations, that body of customs observed by all men and imposed by common consent. But these were differences in terminology: Divine law, natural law, and the law of nations were regarded as aspects of the same universal order, founded on revelation, reason, and custom.
The study of historical and military literature was considered valuable for the art of war. In the late Middle Ages, Vegetius was translated into the vernacular languages and read by increasing numbers of literate laymen. Frontinus, Caesar, Sallust, and Valerius Maximus were also popular. About 1350, the king of France commissioned a French translation of Livy to assist princes to “defend and govern their lands, possess and conquer in proper manner foreign ones, injure their enemies, defend their subjects and help their friends.”6 But they made no distinction between classical historians and more recent writers and read them all in the same spirit, with little awareness that Roman wars had been different from their own. Christine de Pisan was unusual in perceiving that warfare in her day relied much more on cavalry than the armies of Vegetius, but she did not follow up on the observation. Medieval historical writing was not so obsessed with theology as we are sometimes told, but the influence of Christianity and chivalry combined to keep it from becoming an instrument for the exploration of politics and strategy.
One classical tradition that fitted uneasily into the medieval synthesis was that of stratagem. In the eighth chapter of Joshua a feigned retreat and ambush carried out by Joshua against the city of Ai is described, and on this basis, St. Augustine remarked that deceptions were allowed by God in a just war. This contradicted the principle that good faith (fides) must be kept with the enemy in wartime, an observation also found in the works of Augustine and other church fathers. In Causa 23, Gratian tried to resolve the contradiction by concluding that stratagems were allowable only if good faith had not been promised, and later canonists wrestled inconclusively with the problem. There was a general sense that stratagems were permissible in a just war, but this was not an area that the medieval mind wished to explore.7
Early Renaissance Florence: The Rebirth of Civic Militarism
The first crack in the medieval synthesis appeared in Italy around 1400, with the rise of “civic humanism.”8 The magistrates and governing elite of the Florentine republic began to imitate both the literary form and content of classical Latin historiography and oratory. The new style appeared full blown in the early years of the fifteenth century in the Ciceronian orations and Livian historical works of Leonardo Bruni, later chancellor of Florence and the first of a succession of Florentine humanist magistrates who soon spread the new genres over Italy. Unlike earlier humanists like Petrarch and Boccaccio, these men sought to copy the thought, as well as the expression, of Cicero and Livy. They identified themselves with the ancient Romans and absorbed ancient Roman attitudes toward politics and war, as they understood them.
The Romans with whom they identified themselves were the Romans of the republic, not the principate. They bought the interpretation of Roman history they found in the Roman historians: The key to that history was the decline of republican virtue, above all, military virtue. The keynote of the new rhetoric was the ideal of “liberty,” meaning participation in politics, which was seen as the source of all virtue because it inspired heroic achievement. Bruni had picked up a comment by Tacitus at the beginning of his Histories: Virtue only flourishes in liberty, and therefore it declined under the Caesars. This provided a political explanation for the decay of Roman virtue recorded by Sallust and Livy. Bruni and his circle learned from Tacitus that the principate had dealt republican liberty and virtue their death blow. They knew from Sallust that the decline had begun much earlier with the coming of peace. They learned from most Roman authors a glorification of war uninhibited by Christian misgivings.
The Florentine breakthrough was the result of several factors: the consolidation of a tight oligarchy bent on building a centralized state in Tuscany; the weak position of the papacy during the Great Schism, which left humanist circles uniquely free of clerical interference during the early fifteenth century; and the long wars between the Florentine republic and the princely state of Milan between 1390 and 1402, which inspired the Florentine oligarchs to identify themselves with classical Rome and Athens and with classical republican ideals in opposition to monarchy. They were attracted to the military aspect of that tradition because it held out hope that an army of free citizen soldiers would be invincible in war over armies of mercenaries, who were then taking over Italian warfare. The core of the humanist program was revival of the communal militia of Florence—an anachronistic ideal, for these medieval militias were rapidly becoming obsolete in an Italy increasingly dominated by despots and condottieri.
In many ways, this was a limited breakthrough. Bruni5s History of the Florentine People, the great monument of Livian history in the Renaissance, revived all the limitations of Livy: the moralistic biographical approach to history, the lack of interest in causation, the unquestioned dogmas about the justice of Roman warfare and Roman imperialism. Bruni believed that Florence had been founded not by Julius Caesar, as tradition said, but by the Roman republic, for it was essential to the new ideology to make Florence the heir of the republic and not the principate; and he thought this an adequate reason to claim that all the wars of Florence were just, like the wars of the Roman republic, and that Florence had inherited Rome’s just dominion over the world.9 He seriously attempted to trace the origins of the Guelph Party to republican Rome and that of their Ghibelline opponents to the Caesars. In his On War (De militia), he attempted to trace the origins of European knighthood and chivalry to ancient Rome and Sparta. But he never understood how different ancient warfare was from medieval war and placed no special importance upon infantry.
In short, civic humanism was more medieval than it looked. Outside Florence, its rhetoric was imitated more than its ideas, and even at Florence, it was dying in the later fifteenth century under the rule of the Medici. But the humanists had given currency to certain seminal concepts about politics and war that eventually bore fruit in the work of Machiavelli.
Notes
1. For a survey of the just war tradition, see J. T. Johnson, Ideology, Reason, and the Limitation of War: Religious and Secular Concepts, 1200-1740 (Princeton, 1975), and fust War Tradition and the Restraint of War (Princeton, 1981).
2. Michael McCormick, Eternal Victory: Triumphal Rulership in Late Antiquity, Byzantium, Early Medieval West (Cambridge, 1986).
3. The issues touched on here are discussed in nearly all the vast literature on Augustine’s political thought; see especially C. N. Cochrane, Christianity and Classical Culture: A Study of Thought and Action from Augustus to Augustine (New York, 1957).
4. F. H. Russell, The Just War in the Middle Ages (Cambridge, 1975), is comprehensive. There are discussions of medieval theories of warfare in Hans Delbrück, History of the Art of War, 4 vols., trans. W. J. Renfroe, Jr. (Westport, Conn., 1975-1985), vol. 3, Medieval Warfare, and Philippe Contamine, Warfare in the Middle Ages, trans. Michael Jones (Oxford, 1984).
5. M. H. Keen, The Laws of War in the Late Middle Ages (London, 1965).
6. Contamine, Warfare, 214.
7. Consult the index in Russell’s Just War under “ambush.”
8. Hans Baron’s The Crisis of the Early Italian Renaissance: Civic Humanism and Republican Liberty in an Age of Classicism and Tyranny, 2 vols. 2d ed. (Princeton, 1966) gives the classic interpretation of the origins of modern republicanism. Its military aspects are studied by C. C. Bayley, War and Society in Renaissance Florence: The “De Militia” of Leonardo Bruni (Toronto, 1961).
9. Bruni, “Panegyric to the City of Florence,” in The Earthly Republic: Italian Humanists on Government and Society, ed. B. G. Kohl and R. G. Witt (Philadelphia, 1978), 150.