Darrell Cole insightfully summarizes the views of C. S. Lewis in his Touchstone essay:

Lewis had been a soldier, so he knew what it was like to experience that essential nature of all battle, so aptly summarized by Homer as “men killed and killing.”

Thus, Lewis possessed the mind of someone at home with just-war doctrine, and he had the experience to know its applicability to modern warfare. Indeed, his battle experience consisted of enduring the rigors of the trenches in the First World War, arguably the most horrible kind of warfare the world has ever witnessed. If there ever was a type of warfare designed to turn the most hardened veteran into a pacifist, surely it was the kind of warfare seen at the Somme in 1916. Yet Lewis was never a pacifist, and, in fact, he argued vigorously against pacifism on a number of occasions. . . .

The Failure of Pacifism

Lewis gave a paper to a pacifist society in 1941, stating fully the reasons why he was not a pacifist.2According to Lewis, pacifism fails to persuade on every level of moral judgment: facts, intuition, reasoning, and authority. For many modern Christians, there are two pertinent facts: War is evil, and war is necessary. Thus, such Christians are persuaded by the “facts” that they must do necessary evil. Lewis is too careful a thinker to fall into such a trap. For him, war is certainly disagreeable, but it is not necessarily evil.

Christian pacifists go further than most modern Christians, and argue that war does no good at all. As Lewis rightly points out, such a claim involves asserting that the historical changes that would have ensued had wars not been fought would have made the world no worse or even better than it is now, after all our wars. In other words, the world would be no worse off today—and might even be better—had Britain and her allies in World War II simply let Hitler do what he wished in Europe (and the rest of the world for that matter). Of course, this is patent nonsense, and Lewis is right to point it out when he sees it. History is full of both useful and useless wars.

Intuition provides a stronger case for pacifism. We seem to feel very strongly that love and helping are good, while hate and harming are bad. What this intuition fails to tell us, however, is how we are to love and help the innocent who are being treated unjustly by the wicked without using force on the wicked. So intuition in this case leads us astray because it does not see (not immediately at least) what reason sees: that you can love and use force at the same time. Lewis deals with this point explicitly in the chapter on forgiveness inMere Christianity:

[F]or loving myself does not mean that I ought not to subject myself to punishment—even to death. If one had committed a murder, the right Christian thing to do would be to give yourself up to the police and be hanged. It is therefore perfectly right for a Christian judge to sentence a man to death or a Christian to kill an enemy.

When we use force in a just cause, we do to others as we would have others do to us. We admit that, if we do evil, then we hope there will be someone who is able to stop us from doing it—even if he has to use force to stop us. Thus, we are led by logic to admit that, if we see evil being done by others, we need to stop them if we are able, even if it means using force.

Authority, too, is against the pacifist. Every human society has said that some wars are good and that every citizen benefits from some wars (most obviously, wars of self-defense). The Christian tradition since the fourth century has declared that some wars are good.

Yes, opinion was divided in the first two centuries, but not nearly as much as popular opinion would have us believe. The first Christians were held in suspicion by the Roman authorities, and, to make matters worse, participation in the Roman army meant engaging in pagan rites such as emperor-worship. But we find little evidence of the earliest Christians rejecting military service on account of a moral aversion to bloodshed. Most of the early church fathers who speak on the subject of just war speak with approval.

In fact, the “pros” clearly have it over the “cons.” Clement of Alexandria, Origen (who was unique in limiting Christian support to prayer for the troops to succeed), Eusebius, Basil, Ambrose, Chrysostom, and Augustine all admit to the goodness and usefulness of just wars. Only Tertullian can be listed on the pacifist side. The great early Reformers, such as Tyndale, Luther, and Calvin, were all proponents of the just war. Only the radical reformers rejected the notion of a just war.

Reason is clearly against the pacifist on all fronts, except, perhaps, one: the teaching of Jesus that one should “turn the other cheek” (Matt. 5:39). Lewis readily admits that it is hard to deal with people who base their entire theology on a few verses—this in itself seems to go against reason—but he does have a response. If we are going to take all of Jesus’ commands at face value, then pacifists should also sell all their goods and give them to the poor. They should also quit burying their loved ones (“leave the dead to bury the dead,” Matt. 8:22).

Fortunately, we have the Apostle Paul to help us here. When Jesus tells us to turn our cheeks when struck, he means that we should not retaliate out of vengeance. We leave vengeance to God, who works his vengeance on the evildoer through the State’s use of the sword. Christians are called upon to support the State, which has been ordained by God just for the purpose of using the sword to establish and maintain justice (Rom. 12–13). This better accords with the rest of the New Testament—not to mention the Old Testament, where God commands killing on quite a number of occasions! Pacifist logic leads us to say that Paul, Peter, and the writer of Hebrews (who, in the eleventh chapter, commends to Christians as people worthy of imitation those Old Testament warriors who waged war for justice) all misunderstood the teachings of Jesus. . . .

The Good of War

Lewis once remarked that he could understand the honest pacifist, though he considered him “entirely mistaken.” What he could not understand was “this sort of semipacifism you get nowadays which gives people the idea that though you have to fight, you ought to do it with a long face and as if you were ashamed of it.” . . .

Just (and human) wars are wars whose failure to prosecute makes us less than human. Put differently, we fail to be all that we are intended by God to be as human beings when we refuse to fight just wars.

The battles fought in any war will issue in unfortunate acts, for it is essential to injure and kill the enemy if one side is to impose its will on another, and all acts that harm or injure are unfortunate. But unfortunate acts—acts that bring about misfortune—need not be inhuman or evil. We say, for example, that it is unfortunate that the police sometimes have to harm or kill evildoers in the line of duty, but we do not say that such acts, if necessary, are evil and inhuman. To the contrary, we praise the courage and ability of such police officers and hold that it would be positively inhuman and evil for the police to stand by while evildoers took advantage of innocent citizens. . . .

The simple fact of the matter is, according to Lewis, that those who refuse to support their nation in a just war have the easy way out, which should put us on our guard when we find ourselves moving toward the pacifist position. Fallen human beings are naturally prone to justify their unwillingness to suffer hardships. A pacifist’s career is not put on hold in wartime. He suffers none of the hardships of the soldiers who have given up their security and peaceful way of life for the good of others. . . .

The Demands of Chivalry

None of this should imply that soldiering is such a noble occupation that one is ennobled simply by putting on the uniform and fighting. No, noble soldiering takes a great deal more than proper clothing, equipment, and opportunity for killing. Noble soldiering takes virtue, and this is what chivalry was and is all about.

Lewis’s essay on chivalry is an exemplary argument about Christian just war-making.7Lewis saw what few of our contemporaries do: that just war requires just people to wage it. Chivalry is, properly speaking, the character that enables human beings to be “fierce to thenth degree and meek to thenth degree.” Thus, the medieval ideal brings together two things that do not grow together naturally in a human being: fierceness and meekness. To acquire such a character is no easy matter. As Lewis reminds us, the knight is a work of art, not nature. Those who are naturally fitted to war-like pursuits will have to acquire the virtues of humility and mercy to supplement their inherent fierceness. Those who are naturally meek will have to acquire the virtues of courage and valor to supplement their natural humility and mildness. Truly such a “double demand on human nature,” as Lewis calls it, requires the grace of God. . . . 

Death in Battle

Also, oddly enough, it is the liberal-humanist view of war that demonizes the enemy, who must, in its eyes, be irrational to cause so inhuman a thing as war. Lewis’s notion of the healthy respect for enemy soldiers that war-as-tournament breeds is illustrated quite well in this controversial passage:

I have often thought to myself how it would have been if, when I served in the First World War, I and some young German had killed each other simultaneously and found ourselves together a moment after death. I cannot imagine that either of us would have felt any resentment or even any embarrassment. I think we might have laughed over it. (Mere Christianity,107). . . .

The Witness of Christian Soldiers

As we have seen, the knightly character is something that we must strive for if we ever hope to achieve it by God’s grace. The natural virtues of wisdom, justice, courage, and self-control guide Christians to decide when they can make their nation’s war their war. Nevertheless, Christians must realize that they cannot possess the same degree of wisdom on certain aspects of war that a nation’s leaders have (at least we hope our leaders have it). This is especially acute when it comes to determining the criteria for reasonable hope of success. In the previously mentioned letter to the journalTheology,Lewis argued correctly that ordinary citizens often lack sufficient training to decide whether a given war is winnable. Thus, Christians do not have the same duty or right as have their leaders to decide when a war is unjust. Instead of trying to decide if every criterion of thejus ad bellumis met (unless, of course, there is some gross and obvious violation), Christians would better serve themselves and the State (in the capacity of a witness to the nations) by making sure that they act justly in war. . . .

Lewis’s point is this: If Christians want to be a witness to the State, to get the attention of the non-Christian populace, then why not do something that really matters, such as go to war but refuse, say, to murder prisoners or bomb civilians?

You can read Darrell Cole’s entire essay here:

http://www.touchstonemag.com/archives/article.php?id=16-03-045-f#2