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Appeared in Vol. I, No. 2

In this provocative study, John H. Cleland takes up the problem of the crusade. Beginning with the question of whether or not the use of physical coercion—even killing—can be a truly Christian action, the author analyzes the pertinent sources to lay the foundations of a crusade theology. Such a theology has broad and obvious implications in the modern world. A thorough study, Cleland’s article will be divided into two major parts, the second to appear in the next (Winter 1975-76) issue. In that issue he will conclude with an examination of the ethos of Christian knighthood. In the first part, which follows, he concerns himself with the basic underpinnings of the crusade ideal in philosophy, justice and Scripture.

Europe’s long series of specifically Christian military expeditions to the Middle East continue to act as one of the great rocks of history on which opinions cleanly divide. As do few other historical events, these events seem always to force their lay and professional auditors to take a stand. It is very difficult to wade through all the bizarre heroics and all the bloodthirsty excesses of the crusades without coming down either strongly in favor of these wars, despite their well-known evils, or strongly against them, despite their rarely-acknowledged merits, without finally saying yes or no to the whole business. The danger of confronting history in so personal a manner is an understanding oversimplified to the point of distortion. Balancing that danger is the corresponding opportunity of ethically plunging past historical speculation to the crossroads where speculative understanding and personal commitment meet. One need not accept as true Karl Marx’s ‘law’ about history’s contingent events to hold with him that the practical point of studying the world at all is not to interpret it but to change it. (1)

The founders of crusade theology who are discussed in this paper, though some of them lived long before the crusades, were certainly interested in changing the world. That is not by any means to say that they ignored the supreme human dignity of speculative thought. Indeed, much of that which follows deals with their speculations about what is necessarily true of war, always and everywhere. The founding fathers of the crusades disagreed to a man with any Marxian-like inflation of human possibilities here below. And yet they fathered an idea whose historical impact—after 700 years—challenges that of communism. The very term crusade persists to this day as the most exact one-word description in English of any idealistic enterprise.

The men originally inspired by the ideal participated in crusades that stretched over nearly 200 years, from the 11th to the 13th centuries. (2) Those crusaders were in part successful. That in the end they failed to achieve their central objective, to rid the Holy Land of Moslem occupation, is only what may be said of nearly all the grand historical designs that God’s providence so far has molded. That the good the crusaders also did was largely leavened with evil may be said of every war that has ever been waged.

Before tracing the development of the seminal strands of crusade theology, it is worth briefly reviewing the certain and presumable facts that led Pope Urban II to call in 1095 for the First Crusade. The foremost fact was Turkish occupation of Jerusalem, since 1076, and the attendant interruption of Christian pilgrimages to the Holy Land. Another was the papacy’s desire to reinforce Byzantium against continuing Turkish attacks, no doubt partly in the hope that supplying this requested help would heal the schism that had split Christendom in 1054. A third fact was the longstanding desire to transform European militarism to ends loftier than violent private wars between Christians. These were strategic considerations of capital importance for the Church.

Giving them motive power were the private interests of the crusaders. In many of the warriors, as their subsequent actions bore out, those interests were base: the desire for gold and precious materials from the east, the territorial greed of landless nobles, sheer thirst for adventure and blood. Still, the main-spring of the action as a whole was the manifest spiritual impact on six generations of the central promise of the Christian faith: God’s offer to unite the very core of His being with that of any man who first perfects himself through service and sacrifice. There is no rational way to verify or even account for that offer. It is a mystery. But it is an intelligible mystery, at least to those who believe Christ is who He claimed to be and meant what He said.

Well-documented service and sacrifice did in fact flow in response to what the crusaders believed was Christ’s authentic invitation to pick up the cross of war and follow Him. the cross they picked up was not made of foam rubber. That they picked it up at all suggests a further fact to the Christian understanding, a mystical fact in the true sense of that word. for if the thesis of this paper—that the foundations of crusade theology were solidly and lastingly built—turns out in fact to be true, then it becomes reasonable to believe that the better crusaders began at least to live the interior life of grace and union they sought. It becomes possible even to believe, without exaggeration, that the very finest of the crusaders lived that interior life in its highest degrees of mystical intensity. The possibility of those interior dispositions in many crusaders and the spiritual ends of papal policy to which the interior dispositions were harnessed explain, in the fullest sense, why the epithet holy attaches historically to these wars.

That a war in Christ’s name can be holy merits some discussion. some contemporary historians claim that the Church of the first three centuries was pacifist on principle. they often cite in support of that argument two or three demonstrable facts. They point out that Christianity, unlike Islam, was not born militant. They cite a number of leading Christians of the era whose thinking does in fact show a pacifist tendency. And they point to the wholesale abstinence by early Christians from service in the Roman army.

To put these facts into context, however, is to make the pacifist case much less than air-tight. Christians living in apostolic times and the centuries immediately following were an isolated, alien minority with no public responsibilities. There is no question that the Church was slow to come to grips with the paradox of war and peace. Some early Christian thinkers, Tertullian most colorfully, even advocated secession from society. Others such as Origen drifted toward a general feeling that it is always wrong to kill a fellow human being, since each person is created in the image of God: “. . . God did not deem it becoming to His own divine legislation to allow the killing of any man whatever.” (3) Refusing to serve in Rome’s military, however, made good moral and practical sense apart from pacifist principles. Adherence to the First Commandment of God and to a first principle of common sense surely were reasons enough to shun if not despise an army that made idol-worship obligatory and enforced Rome’s official anti-Christian policies. And Tertullian, Origen, and some others to the contrary notwithstanding, there is no record of the teaching authority of orthodox early Christianity ever even addressing itself to the matter of war directly. The bishops of the first three centuries evidently considered that they had more important pastoral matters to attend to.

Nor did the church have any need to lead society as a whole in matters of war and peace until Constantine started Christianity on its way to becoming the master ideology of the Greco-Roman world. With the Edict of Milan in 313 Christianity’s sense of public responsibility, temporal as well as spiritual, began to grow. By degrees, the Church realized how radically opposed Christian peace and temporal war seem to be. The question was how war could be reconciled with Christ’s clearest command of all, that of loving and serving one’s neighbor even to the point of returning goodness for evil. If reconciliation were impossible the Church would face the clear dangers of two possible conclusions. Either Christian dogma would appear inapplicable for men living in ordinary society, and at best irresponsible counsel for them; or else society would appear so unreal for true Christians that they would have to secede as gracefully as possible from it, as Tertullian suggested, and let the world go its own way.

As it turned out, a series of leading churchmen, starting with Ambrose, began to develop an approach to the question of war which would be consistent with the new opportunity and challenge of Christians to discharge political and social responsibilities of a public nature. Only the most prominent of those engaged in the effort can be dealt with here. The spiritual and polemic genius of Roman Africa, Augustine, has a lasting influence on the theology of war. Three other great doctors of the Church must be classed as founders of the theology that led to and confirmed the legitimacy of the crusades: Ambrose, Bernard of Clairvaux, and Thomas Aquinas. Two Byzantine emperors, Justinian and Heraclius, and several single-minded popes of the 11th and 12th centuries, built important ideas into the foundations. Finally, the canonists Anslem of Lucca and Gratian contributed significant architectural touches. (4)


Many today think it outrageous to employ physical force for spiritual ends. That view, however, does not take proper account of the full implications of the medieval—or indeed the Christian—metaphysical understanding that a whole person has two components: a corporeal body and an immaterial soul, both of which are needed for true human existence. The recognition of this duality in human existence obviously has great implications for interpreting the legitimate means of action of the Church.

An instructive contrast between modern and medieval conceptions of the Church is offered in Arnold J. Toynbee’s interpretation of the Investiture Controversy, a series of events that watered all the taproots of crusade theology. Toynbee analyzed what he called the “Hildebrandine tragedy,” or “downfall of the papacy.” He concluded “that the use of material means toward a spiritual end is always a dangerous game.” (5) Then he said:

To live dangerously, however, is the inevitable condition of being alive at all; and there is no decisive evidence for the operation of a moral Gresham’s law to make it certain that, whenever force is employed in a spiritual cause, this dangerous manoeuvre will always incur defeat. (6)

But it usually will, Toynbee implied. And to prove that thesis, he attributed to Pope Gregory VII—for ‘wrongly’ choosing material ways and means of combating imperial force—many of the modern ills of Christianity. Perhaps Toynbee was right. But what interests me more, here, is the metaphysical inference that may be drawn from his metaphor about Gresham’s Law. The inference is that there is not only more worth in using spiritual rather than material means to accomplish spiritual ends, but that the two means are mutually exclusive. Toynbee was concerned to judge Gregory’s actions not so much by the standard “thou shalt not kill” as by the standard “thou shalt pray.” A corollary inference seems to be that while danger is the inevitable condition of being alive as a person, it is not even a desirable condition of being alive as an organized Church. He conceived of no legitimate material extension of the Church, of any consequence, and no extension at all into arenas of normal human action.

Now the medieval view of things did not deny the ultimate superiority of the spiritual realm. But it flatly contradicted, as I have suggested, the idea that the Church is therefore confined to addressing her energies and members only to that realm of life. Even mystically-inclined saints gloried in the physical implication of life. Francis and Bernard and Bonaventure, for example, were outstanding exponents of the great good men can derive by honoring and acting upon the carnal, or bodily, values of life. These values they considered the ordinary first stage of human growth into a more purely spiritualized existence. The ascetic lives these holy men also lived suggest the further need they felt to consecrate themselves in some way to the service of God. But although their asceticism plainly rejected all excessive stress on carnal values, it did not contradict one of the central lessons taught by these three saints: that there is a positive, though fallen, nobility in the flesh-and-blood side of God’s earthly creatures; that this nobility inheres especially in all rightly-directed human actions, even such humble actions as eating or such coarse actions as fighting; and that devotion to Christ’s humanity, as distinct from His divinity, is a necessary first step for carnal men who wish to raise their sights higher. (7)

The medieval view also contradicts Toynbee’s as to the raison d’etre of the Church. The crusades themselves make clear that ordinary Christians of that age saw the Church as more than the earthly repository of divinely-revealed truths and the presiding authority for liturgical service. They saw their Church as a flesh-and-blood organism intended for normal action in the world as well as for religious worship, and dedicated, both physically and spiritually, to embodying Christ’s ideals on earth. The response to papal appeals between 1095 and 1270 was voluntary. And it is worth remarking that no pope or saint could have launched a crusade if the laity had not voluntarily answered his call.

A 19th century English historian, J.A. Froude, caught the medieval flavor more clearly than Toynbee when he wrote:

The animal and the spiritual are not contradictories; they are complements in the perfect character; and in the middle ages, as in all ages of genuine earnestness, they infused and penetrated each other. There were warrior saints, and saintly warriors; and those grand old figures which sleep cross-legged in the cathedral aisles were something higher than only one more form of the beast of prey. (8)

The medievals believed, in short, that both the physical and spiritual aspects of being human fall on the same long and unbroken continuum of reality. This conviction was the glue that held Catholic Christianity together for 1,000 years. It enabled Popes Gregory VII and Urban II and their successors to focus and hurl Christians first against the Empire and then against the Saracens. And at bottom it was a metaphysics of man and a working vision of the Church that, for all their differences in emphasis and style, Augustine and Thomas Aquinas essentially shared.

The bishop of Hippo is often interpreted by historians of ideas as a Neo-Platonic Christian, or even as a Neo-Platonist who happened also to have been a Christian. His theory of man is then boiled down to posit some sort of self-sufficient soul imprisoned—for 50 to 100 years on earth—in a body. That is an exaggerated reading. Augustine was intensely spiritual, but not naively so. There is simply too much in his works, for one thing, about the reality of the physical side of life. In The City of God, for example, his praise of the beauty of the human body, as it will appear in the next life and as it exists even in this one, is almost ecstatic. (9) Nor does the view that Augustine considered himself an imprisoned Neo-Platonic spirit well account for his 40-year career as shepherd of what may reasonably be supposed to have been an ordinary, more-worldly-than-spiritual cross section of men and women—a collection of people who presumably needed his down-to-earth counsel very much, his spiritual genius not much, and his awesome intellect not at all.

But nothing so well explodes Augustine’s supposed neo-Platonic flight from reality as the political Augustinianism that threads its way through his works. In his reply to Faustus, for example, he spoke without any trace of the flight from human existence that metaphysically characterizes the Platonic Ideas. Augustine said this:

What is the evil in war? Is it the death of some who will die soon in any case, that others may live in peaceful subjection [he is referring to the wars of Moses against gentile tribes living in the Holy Land]? This is mere cowardly dislike, not any religious feeling. The real evils in war are love of violence, revengeful cruelty, fierce and implacable enmity, wild resistance, and the lust of power, and such like; and it is generally to punish these things, when force is required to inflict the punishment, that, in obedience to God or some lawful authority,  good men undertake wars, when they find themselves in such a position as regards the conduct of human affairs, that right conduct requires them to act, or to make others act in this way. Otherwise John, when the soldiers who came to be baptized asked, What shall we do? would have replied, Throw away your arms; give up the service; never strike or wound, or disable anyone. But knowing that such actions in battle were not murderous, but authorized by law, and that the soldiers did not thus avenge themselves, but defend the public safety, he replied, “Do violence to no man, accuse no man falsely, and be content with your wages” (Lk. 3:14). (10)

That passage is representative of the sort of idealism Gilson finds radically different from Cartesian idealism, and of the sort of method that affirms the wholeness of man—body and soul—by first identifying man’s spiritual reality and then drawing from that logical inferences about his carnal reality. Gilson wrote:

The sum of St. Augustine affirms at one stroke the existence of man—not only one half of him, destined to struggle desperately to rejoin the other half.

It is at this point, it seems to us, that the original deviation inflicted by modern Augustinianism on the authentic Augustinianism must be sought. There is a great temptation to see in it nothing more than an inconsistent idealism. Yet, if we may be allowed to use an expression unknown to St. Augustine, his philosophy is just as realist as that of St. Thomas Aquinas.(11)

The fact that Gilson is a thinker of essentially Thomistic persuasion does not alter the correspondence of his point here to the Augustinian passage that precedes it.  In that passage, Augustine did not attempt to paper over either war or the possibility of sin in warfare. He located any sin involved in soldiering in the will and motivation of the soldier. He treated the death and suffering and fraud and greed and cruelty and wrong that always occur in war with a psychological realism that frankly admits their real existence. He paid controlled brute force the compliment of calling it a positive good when it is embodied in a good will and employed properly “in the conduct of human affairs” against evil-doers. He thus went well beyond justifying war negatively, as an evil that may only be undertaken when the alternatives are more evil still. In war, as in all else for Augustine, everything depends on the will, which is either good or bad.

All of this mainly proceeds, in my opinion, not from any Puritanical infatuation with Old Testament warfare; not certainly from any secularist infatuation with the City of Man; not from any great need to extricate the Catholic Church of his day from the grip of imperial force; not even from any desire to found an ethos of war, despite the fact that he did originate the just-war theory and a little more. Augustine’s thought proceeds, rather,  from a metaphysical recognition that man is animal as well as spiritual, and from the consequent psychological realism that accepts force and war as conditions that can never be eliminated. He says they may be ameliorated, however: by making careful theoretical distinctions about where the evil of violence necessarily resides. And he explains how, as a practical matter, to ameliorate them: by eliminating what truly is evil from Christian conduct.

This line of thought enabled Augustine to interpret Christ’s words about the Church not being of this world to mean that its essential purity tends to raise it above the things of earth, without suggesting that the Church’s work does not lie in this world, among men who may be as real and as menacing as the Seljuk Turks, and within the framework of human interests and institutions, even when those interests and institutions initiate or are dragged into war.

Thomas Aquinas codified Augustine’s theory of war and lived late enough in the crusade period to be able to apply the formulation to those very wars. And where Augustine had made careful theoretical distinctions mainly about the interior dispositions of warriors, Aquinas made equally careful ones concentrating on the external conditions of wars. Thomas taught that a just war has three distinguishing characteristics. It must be: 1) engaged on the command of an authority (political or religious) responsible for the common good; 2) truly needed to rectify some wrong; and, 3) conducted with the general intention of advancing good or avoiding evil. (12)

Around the time he was preparing that formulation for the article on war in his Summa, he conducted one of those academic debates that were called Quodlibetal Questions. In it he added theological precision to the idea of the special crusade indulgence (or commutation of penance) that, along with papal authorization, constituted one of the defining elements of a crusade in canon law. Thomas outlined the requisite authority and cause of such a war and the subjective state necessary in a crusader for efficacious reception of the indulgence.

In order for an indulgence to be valid, three things are required: first, a cause pertaining to the honor of God, or utility of the Church; second, authority in him who grants it, for it is principally the Pope who can grant an indulgence, but others can insofar as they receive power from him; . . . third, it is required that whoever wants to receive an indulgence must be in a state of charity.  These three things are delineated in a papal letter [which grants a crusade indulgence]. A suitable cause is designated when “the support of the Holy Land” is specified; a proper authority is designated when the authority of the Apostles Peter and Paul and of the Pope himself are mentioned; and the charity in the recipients is designated when the papal letter speaks of “all who are truly penitent and confess [their sins].” (13)

It is important to note the conditions here set forth. There is a demonstrable need for armed intervention in a specific place. There is demonstrable authority in the office of the man who calls for that intervention. And there is a definite interior disposition needed in anyone who hopes to be rewarded for answering that call.

It seems to me that Augustinian and Thomistic philosophical principles complement each other with special force in the development of crusade theology. Augustine made lasting distinctions between soft pacifism and hard cynical realism. He recognized that both sinfulness and goodness in the human soul have material consequences and, in the case of the latter, resulting material responsibilities as well. Thomas completed the picture. He in effect distinguished between genuine religious warfare, the secondary causes of which can be defended on rational grounds, and the counterfeit religious warfare that springs from some claimed perception of the arbitrary working of God’s will, the secondary causes of which cannot bear scrutiny. Thus Christian philosophy more than overcame the seeming contradiction between making war and turning the other cheek.


If it may be said that Christian philosophy even went beyond the just-war theory, I think it also fair to say that medieval Christianity’s understanding of justice edged war theory in general even closer to proclaiming the positive good that some controlled application of force can occasionally do. The canon lawyers Anselm of Lucca and Gratian were important in this development of crusade theology, although the earlier tone set by Ambrose and Augustine has had an even more lasting influence on the Christian attitude toward war. And giving systematic embodiment to this tone, to a degree beyond even that of Charlemagne, was the Christian Roman Empire, especially as led by Emperors Justinian and Heraclius.

Ambrose was an extremely important figure in the building of this foundation of crusade theology, more because of his force of character than because of his ideas, even though his ideas were not negligible. The fiery bishop, idolized even by the great Augustine, did more than make sure that state officials never forgot that they too, as individuals, were in and not superior to the Church. He proclaimed that the state as such is “good and within the purpose of God”—thus opening the way for Thomas Aquinas’ elaboration of the same theme centuries later—and that the Christian state, moreover, had important material responsibilities in advancing Christian interests. (14) Representative of the robustly pro-Christian stance Ambrose expected from the heads of Christian states is this passage from his letter to Emperor Valentinian, regarding the pagan party’s attempt to reestablish the Altar of Victory:

. . . God, of course, is to be preferred to all men. . . . No one is injured by having almighty God preferred to him. The pagan has his own views. You do not compel him to worship anything against his will. You, Sir, should be allowed the same freedom. . . . A man should frankly defend his convictions and adhere to his purpose. (15)

It is a very short step from that kind of policy to at least selective application of coercive material force within a state. And from that, it is but another short step to application of power beyond the borders of a state. Both fall under state defense of the faith.

The English historian Christopher Dawson summed up the role of Ambrose:

In St. Ambrose, above all, the Western Church found a leader who could maintain the rights of the Church no less vigorously than St. Hilary, but who was at the same time a loyal friend of the emperors and a devoted servant of the Empire . . . a Roman of the Romans . . . the first exponent in the West of the ideal of a Christian state, as was Eusebius of Caesarea in the East. . . . He stands midway between the old classical ideal of civic responsibility and the mediaeval ideal of the supremacy of the spiritual power. He was something of the Roman magistrate and something of the mediaeval pontiff. (16)

The Byzantine Empire over a long period embodied the Ambrosian ideal of church and state, although with more political control of the church than Ambrose himself would have tolerated. In the view of Helene Ahrweiler, Byzantine emperors up to the 8th century effectively lumped together the enemies of their state and the enemies of their religion. The highest good their politics sought to generate, in Ahrweiler’s view, was order; both peace and war were put in the service of maintaining that order. (17)

This interpretation explains Justinian’s alternating efforts to repress the Monophysite schismatics on one hand and on the other to persuade the Church to modify its Christological doctrine in order to appease the Monophysites. It also explains how Heraclius’ campaign to regain Jerusalem from the Persians took on, in the view of H. St. L.B. Moss, “the aspect of a crusade”. (18) It was a view of natural justice, then, that inspired the Byzantines to impose order on the civilized world and to build up Christianity in the process.

Augustine’s view of history supported this conception. Far from dispensing with justice in the natural order because of his exalted view of the city of God, he claimed that eternal law “forbids transgression of it [natural virtue, or justice].” (19) In another place, he explained why it is so important to protect one of the main derivatives of the natural order—human society:

We give a much more unlimited approval to their idea [that of the Stoics] that the life of a wise man must be social. For how could the city of God (concerning which we are already writing no less than the nineteenth book of this work) either take a beginning or be developed, or attain its proper destiny, if the life of the saints were not a social life? (20)

Two pages later he lamented but did not deny the Stoic maxim that “the wise man will wage just wars”; and he in fact attributed truth to the maxim because of the “wrongdoing of the opposing party,” by which he meant the sort of wrongdoing that seriously injures society.

Augustine rejected any identification of the interests of Rome and of Christianity. Even so, he was not averse to calling in the coercive power of the state to help put down the Donatist schismatics, who were still creating great turmoil in the Africa of Augustine’s time. This invocation of force grew out of one of the chief dicta of political Augustinianism: that a little coercion applied with necessary precautions and for the purpose of protecting society, can bring about positive good. He wrote this to Marcellinus, for example:

These precepts concerning patience [those of Jesus] ought to be always retained in the habitual discipline of the heart, and the benevolence which prevents the recompensing of evil for evil must always be fully cherished in the disposition. At the same time many things must be done in correcting with a certain benevolent severity, even against their own wishes, men whose welfare rather than their wishes it is our duty to consult. . . . And on this principle, if the commonwealth observe the precepts of the Christian religion, even its wars themselves will not be carried on without the benevolent design that, after the resisting nations have been conquered, provision may be more easily made for enjoying in peace the mutual bond of piety and justice. (21)

The sort of thinking reflected in the foregoing dictum seems clearly to have inspired Anselm of Lucca’s theological attempt to complete the reconciliation of coercive force and charity. Paraphrasing from On Charity, Anselm’s chief theological work, Father Leclercq says physical force is employed charitably when it protects those who wish to live a good life, by destroying those who harry them; or when it is employed with the intention of morally healing wrongdoers. (22) In a later footnote, Leclercq comments that R.W. Southern’s description of Gratian’s Causa XXIII as “the first serious discussion on problems of war in Medieval Europe” fails to take proper account of Anselm’s work. (23) That is probably true, in terms of post-Augustinian Europe. But both Anselm and Gratian mined the rich ore of charitable coercion in Augustine.

One of the important distinctions Gratian made in his Causa XXIII is between injuries committed against one’s own person and those committed against God and/or one’s neighbor. He cited a letter Pope Gregory the Great wrote to one Bishop Ianario. In the letter Gregory reprimanded the bishop for imposing sanctions on someone who had physically attacked him (Ianario).

The Lord, moreover, wishing them to bear injury to their own person with patience and gladness . . . [said]: Rejoice in that day when men will curse you and say all kinds of evil against you: exult, because your reward in heaven will be great. Hence sins which are committed against God or against our neighbor must be punished by us. But those things which are done against us must in truth be borne patiently. (24)

Gratian’s point is that sins against one’s own person should be borne patiently, but sins against God and neighbor ought to be punished out of charity.


There is no shortage of Scriptural texts, in either Testament, that explicitly or implicitly condone the employment of legitimately-directed coercive force. Nor is there any absence in the New Testament, specifically, of interpretations that see more than ordinarily is seen in the peace-making injunctions of Jesus Christ. Still, exceptions to a general rule do not themselves inspire the construction of a theology, or even the building of one foundation of a theology. There must be positive inspiration as well. The inspiration of Scripture as a whole is clear. (25) From the Serpent’s hostility to God in the Garden of Eden (Gn. 3:1, 14-15) to his absolute and everlasting defeat in the final apocalyptic struggle (Ap. l2:9; 20:9-10), there is in salvation history an underlying, unifying, multicolored theme of warfare between God and His enemies. In Old Testament history Yahweh, the God of Israel, fights His own and Israel’s enemies in holy war, the terminology of which takes on in the Prophets’ “day of the Lord” an eschatological significance. At least one major historian of the 12th century, Father Chenu, claims the crusades were modeled on Old Testament warfare:

It was clearly in the Old Testament that the crusade . . . found its inspiration, its basis, its rules, and all the ambiguities concerning worldly messianism that form a usual part of the imagery of the prophetic books. The “Lord of hosts” becomes not only the mystical but the earthly triumphant conqueror in that holy war. (26)

Chenu’s claim is at least partially borne out in Bernard of Clairvaux, some of whose letters burn with a special intensity on Old Testament themes. Bernard had the highest praise for the Maccabees, whom he said “alone of all the ancients had in common with our martyrs not only the same cause for their martyrdom, but also the same kind of martyrdom. . . .” (27)

Other commentators, Alphandery for example, found the New Testament call for sacrifice an even stronger source of inspiration for the crusades than the Old Testament wars. That inspiration surfaces in the penitential aspect of medieval pilgrimage, a theme that is often expressed in the writings of Bernard, a number of popes, and others. The layman who composed the Gesta Francorum, for example, began his book with this informative sentence:

When that time had already come of which the Lord Jesus warns his faithful people every day, especially in the Gospel where he says “If any man will come after me, let him deny himself, and take up his cross, and follow me,” there was a great stirring of heart throughout all the Frankish lands, so that if any man, with all his heart and all his mind, really wanted to follow God and faithfully bear the cross after him, he could make no delay in taking the road to the Holy Sepulchre as quickly as possible. (28)

Roland H. Bainton, whose scholarly book Christian Attitudes Toward War and Peace is written from a pacifist standpoint, admits that “appeal to the Bible is not determinative” in the subject matter of his work. After mentioning a few of the conflicting models of war and peace in Scripture, he concludes:

The appeal to Christian love does not settle the case, because if God be love, then love and killing cannot be incompatible, since God in the end terminates every life, and often prematurely. (29)

Purely in terms of killing, which certain Old Testament and even New Testament books condone as licit under certain circumstances, (30) Bainton is probably right about the theoretical indeterminateness of Scripture. But in terms of the larger matter of war, a book which teaches that there is a time for peace and a time for war (Ecclesiastes 3:8) can hardly be called indeterminate; both conditions are determined to be possible; it is only the timing of each that is open to question. That being so, one can see how easy it would have been for medieval Christians already inclined to fight in the Holy Land to find justification for their dispositions in both Books of Scripture.  The obvious net effect of doing that was to move crusade theology well beyond the theoretical justness of any war, beyond the realm of state defense of the faith, and even a bit beyond the positive good of charitable coercion.



  1. Karl Marx, Theses on Feuerbach in Marx & Engels, ed. L. Feuer (Garden City, 1959), p. 245.
  2. The main expeditions to the Middle East were: a) the First Crusade (1095-99), which captured Jerusalem and established the Latin States; b) the Second Crusade (1147-49), which failed to relieve the Moslem menace after the fall of Edessa; c) the Third (1189-92), which, after the fall of Jerusalem, recaptured Acre and was responsible for the survival of the reduced Latin States in the 13th century; d) the Fourth (1202-05), which captured Constantinople and set up a Latin Empire; e) the Fifth (1218-21), directed against the Moslem power in Egypt; f) the Sixth (1228-29), in which Emperor Frederick II won a brief diplomatic victory; g) the Seventh (1248-54) and the Eighth (1270), the fruitless attempts of Louis IX of France to subdue the Moslems in Africa. (Note: the last Christian possession in the Holy Land was lost in 1291.)
  3. Roland H. Bainton, Christian Attitudes Toward War and Peace (Nashville, 1960), p. 78.
  4. Not all leading Christians favored the development of crusade theology. Peter Damien and Anselm of Canterbury were the most prominent holdouts on the eve of the crusades. I shall pass these by, however, since my subject is how crusade theology grew, and not how it was resisted.
  5. Arnold J. Toynbee, The Downfall of the Papacy in The Investiture Controversy, ed. K.F. Morrison (New York, 1971), p. 123.
  6. Ibid., pp. 123-4.
  7. In analyzing the piety of St. Francis, St. Bonaventure clarifies this aspect of the Christian life (see Journey of the Mind to God, Prologue). But it was St. Bernard more than anyone else who seems to have focused medieval religion on our Lord’s humanity. In his 20th sermon on The Song of Songs he stresses that Christ appeared as man so as to win men’s affections “by first drawing them to the salutary love of his own humanity, and then gradually to raise them to a spiritual love.” This first attraction Bernard termed carnal, which becomes better as it becomes rational, and becomes perfect when it is spiritual. Bernard taught this progression can apply even to the work of war.
  8. Short Studies on Great Subjects (Ithaca, 1967) 111.
  9. St. Augustine, The City of God, ed. R. Hutchins (Chicago, 1952), book XXII, chapters 19, 24.
  10. St. Augustine, The Nicene and Post-Nicene Fathers, ed. P. Schaff (Buffalo, 1887), v. IV, p. 301.
  11. Etienne Gilson, A Gilson Reader (Garden City, 1957), pp. 82-104.
  12. St. Thomas Aquinas, Summa Theologica, 2a2ae, 40.
  13. LeRoy Walters, The Just War and the Crusade in The Monist, 57 (Oct. 1973), p. 587.
  14. Early Latin Theology, ed. L. Greenslade (Phila., 1956), v. V, Library of Christian Classics, 178-81.
  15. Ibid., 194-5.
  16. The Making of Europe (Cleveland, 1956), 55-6.
  17. Speaking on Peace and War in Byzantium, Jan. 18, 1974 at the University of Chicago.
  18. The Birth of the Middle Ages (London, 1935), 139-41.
  19. See note 10 (p. 300).
  20. The City of God, p. 513.
  21. The Nicene and Post-Nicene Fathers, vol. I, p. 485.
  22. Saint Bernard’s Spiritual Attitude to War (1972), in Studies in Medieval Cistercian History III, ed. Bernard McGinn,  p. 6.
  23. Ibid.
  24. Gratian, Decretum, ed. Richter & Friedberg (Leipsig, 1922), Causa 23, q. 4, dicta post causa 26-7: “Dominus autem volens eos iniuriam propriae personae cum patiencia et gaudio tollerare . . . cum maledixerint vobis homines, et dixerint omne malum adversum vos; gaudete in illa die, et exultate, quoniam merces vestra copiosa est in celis. Hinc, idem in omeliis, ostendens, quod peccata, que in Deum vel in proximum committuntur, a nobis punienda sunt, ea vero, quibus in nos delinquitur, patientier tolleranda.”
  25. New Catholic Encyclopedia on War,  volume 14.
  26. M.-D. Chenu, Nature, Man and Society in 12th  C., 158.
  27. The Letters, ed. & tr. James (London, 1953), 145.
  28. The Deeds of the Franks and the other Pilgrims to Jerusalem, ed. R. Hill (London, 1962), p. 1.
  29. Bainton, p. 238.
  30. Paul’s approval of capital punishment (Acts 25:10f).