For over a thousand years, Western civilization was defined by the shifting religious frontier between Christianity and Islam, and the Muslim religion was the ultimate enemy. Whenever Western Christians wished to condemn a person or a movement, the obvious tactic was to compare it to Islam. When a medieval French king wanted to justify his bloody plunder of the order of Knights Templar, he claimed (falsely) that the knights worshiped a sinister pagan idol called Baphomet, a simple mangling of the name of “Mahomet.” In Stuart England, orthodox Christians faced a rationalist challenge from skeptical Deists, and they replied in the traditional manner by accusing their critics of being closet Muslims. As a piece of scholarly name-calling, it is difficult to beat Humphrey Prideaux’s Life of Mahomet (1697), more fully The True Nature of Imposture Fully Display’d in the Life of Mahomet. . . Offered to the Consideration of the Deists of the Present Age.

Anti-Muslim rhetoric is nothing new for Western society, but within the past century, some distinguished Christian thinkers have explored the full significance of that chasm between the Cross and the Crescent. After all, just looking at the countless wars between the two sides, there is remarkably little to choose between them in terms of the saints and villains each produced. Even in the era of the Crusades, it was the Muslims who produced, in Saladin, the true chevalier sans peur et sans reproche. In modern times, it was the highly technological Christian states that inflicted the most horrendous brutalities upon their coreligionist neighbors. This question of distinctions troubled the great Anglican poet and theologian Charles Williams, who dealt with the war between Christians and pagans in his Arthurian epic cycle The Region of the Summer Stars. In one poem (“The Prayers of the Pope”), the pope asks in his prayers: “Where is the difference between us? / What does the line along the rivers define? /Causes and catapults they have and we have, /And the death of a brave beauty is mutual everywhere.” Is it all just a matter of politics, of causes and catapults? Or of who has the most rifles, the best Cruise missiles?

As so often, the best answer to our theological dilemmas may be found in the work of G.K. Chesterton, that remarkable and many-sided writer who, as time goes on, increasingly looks like one of the most important minds of the 20th century. For Chesterton, Christians and Muslims were divided by one simple fact, namely, the Incarnation. The notion that God, the Creator of the Universe, had taken human form, had lived, and died, and was resurrected on earth, was not just one theological point among many: It was the rock upon which all subsequent doctrines and beliefs were founded, including such basic notions as human dignity. Incarnation was not just a truth, but The Truth. As Chesterton wrote in Orthodoxy, “having found the moral atmosphere of the Incarnation to be common sense, I then looked at the established intellectual arguments against the Incarnation and found them to be common non.sense.”

Christians believe in the fact of the Incarnation; Muslims do not; and, therefore, there can ultimately be no compromise between the two. Ideally, Christians and Muslims might well live together in harmony, exercise charity toward one another, and hold intelligent and thoughtful debates—in short, they might act like civilized human beings; but the two world views will always be utterly different, and it is absurd to pretend otherwise. There will also be insuperable obstacles to what is optimistically described as “interfaith dialogue,” since such a process can only advance by having one side abandon its most fundamental beliefs. Chesterton was appropriately amused at the notion that Christians represented an amiable and uncontroversial face of Christianity, a happy ecumenical festival when those of different faiths might come together in harmony, perhaps to watch school plays or see children unwrap presents. He recognized that the whole underlying doctrine of Christmas was the most stark, uncompromising, and vaunting assertion of the core Christian idea, Verbum caro factum est. This is scandal to Jews, folly to Greeks—and unspeakably horrible blasphemy to Muslims. The Koran devotes a whole chapter or sura to having Jesus Himself condemn this appalling doctrine.

Chesterton knew enough of the history of the two religions to understand how very closely related their ideas were, how intimate the two sisters had once been, and this very closeness goes far toward explaining the irreconcilable hatred between Christianity and Islam in their mature years. He argued that Christianity itself had always contained a powerful element of world-denying Idealism, which derived ultimately from Platonism, and he believed (not impossibly) that Islam might itself have grown out of this rival tradition. As he argued in his great biography of St. Thomas Aquinas,

the Greek element in Christian theology tended more and more to be a sort of dried-up Platonism; a thing of diagrams and abstractions; to the last indeed noble abstractions, but not sufficiently touched by that great thing that is by definition almost the opposite of abstraction: Incarnation. Their Logos was the Word; but not the Word made Flesh. In a thousand very subtle ways, often escaping doctrinal definition, this spirit spread over the world of Christendom from the place where the Sacred Emperor sat under his golden mosaics; and the flat pavement of the Roman Empire was at last a sort of smooth pathway for Mahomet. For Islam was the ultimate fulfillment of the Iconoclasts.

In another direction, that anti-incarnational Idealism would flower into the progressive utopianism of the Enlightenment and, subsequently, into modem liberalism. And, as we will see, Chesterton would argue that this seemingly secular tradition would never quite lose its kinship with Islam.

Accepting the Incarnation transforms our understanding of matter, of the created world, which should be seen as a sacramental reality. Christians have thus achieved astonishing success in the visual arts, which reach their greatest heights in images of Christ and, especially, of the Virgin Mary; Muslims, however, eschew all such images. The division between the two religions is symbolized by their respective portrayals of Jesus Himself. In Islamic tradition, Jesus is the focus of countless tales and scriptural passages, which always represent Him as a fierce ascetic who renounced all in the pursuit of God. When the devil taunted the Muslim Jesus for using a stone for a pillow, He threw away the stone, renouncing His last luxury, and slept on bare ground instead. Also, “the day that Jesus was raised to heaven, he left nothing behind but a woolen garment, a slingshot, and two sandals.” The Christian Jesus, on the other hand—Who is, of course, a far better documented figure—seemed to enjoy wine, spurned pious niceties, and delighted in the company of women. It is difficult to imagine any sane host inviting the Muslim Jesus to the wedding feast at Cana.

For Chesterton, Islam was “essentially a simple creed for simple men,” characterized by an “isolated and simplified deity.” Because of its neglect of the Incarnation, it was, above all, unbalanced. As Chesterton wrote in The Everlasting Man, “The truth is that Islam itself was a barbaric reaction against that very humane complexity that is really a Christian character; that idea of balance in the deity, as of balance in the family, that makes that creed a sort of sanity, and that sanity the soul of civilisation.” Islam was founded upon a great denial of matter, a gran rifiuto perfectly symbolized by its rejection of wine and alcohol. These were things which a Christian should see as good and redeemed, intended by God to promote human pleasure and conviviality. To quote a verse of Hilaire Belloc: “Wherever the Catholic sun does shine / There’s music and laughter and good red wine / Or I have always heard it so— / Benedicamus Domino.” The Muslim rejection of this kind of pleasure was a form of world-denial that almost constituted blasphemy in its own right. In Christian terms, it was certainly heresy.

Chesterton was doubly alarmed to find that the Muslim rejection of wine—with all that it implied—was echoed by many good and rational non-Muslims in the early 20th century, those Christians and secular liberals who championed the prohibition of alcohol. Worse, those reformers were trying to remodel human behavior to eliminate the taste for wine—and often, they tried to impose their puritanical standards by seeking to eliminate meat. Tellingly, the progressives were also the ones who rejected the Incarnation and espoused a liberal Christianity that lacked such ideas as the Virgin Birth and the Resurrection. Chesterton argued that their political follies could only be understood in light of their deviant Christology.

In a striking imaginative leap, Chesterton used the symbol of the war against wine to present what might be described as the secular Islamicization of contemporary England and (by implication) the United States. One of his least-known novels is his bizarre 1914 work The Flying Inn, in which he depicts a near-future England in which secular progressives are riding high. (The book has just been reissued by Dover.) The progressives hope to create a well-organized Utopia, free of the curse of alcohol and purified from the horrors of (Christian) religions fanaticism. Then as now, the term “religious fanaticism” was defined as the obviously irrational idea that religious belief should make any difference to everyday conduct, especially when such amended conduct might cause any personal convenience to the believer or to those near him or her. If Christians behaved according to their lights, then they were ipso facto dissidents, who needed to have their personalities modified to conform to contemporary secular mores. So, too, did those bizarre and troublesome eccentrics who foil the schemes of social engineering by creating the “flying inn” of the tide and organizing hit-and-run attacks that permit ordinary citizens to obtain their necessary booze and pub food. In the face of such depraved monsters, no official measures were too severe.

Chesterton’s point was that the humanistic campaign for progress, science, and reason was itself a kind of fanaticism that had its own powerfully religious quality. He is often quoted as saying that “When Man stops believing in God, he doesn’t then believe in nothing, he believes anything,” but this quote proves elusive in his writings, and it may represent a collage of several of his apothegms. What he actually did write in his 1924 story “The Miracle of Moon Crescent” was that ‘Ton hard-shelled materialists were all balanced on the very edge of belief—of belief in almost anything.” Justified by their dogmatic credulity, the social engineers of The Flying Inn inflict a dictatorship worse than anything attempted in the name of orthodox religion, using draconian police powers to root out dissent. Aid liberal secularism finds its culmination in the purest form of world-denying fanaticism—Islam.

The amazing thing about the novel is that the ideological transformation from progressive to Muslim is accomplished so convincingly that we can readily accept it. One of Chesterton’s most striking characters is the progressive prohibitionist Philip, Lord Ivywood, the naive aristocrat who leads the campaign against wine and social nonconformity: He espouses all the faddish causes of his day, including vegetarianism and theosophy, and is, in short, the very model of a modern New Age general. He represents that old patrician intellectual lineage that traces back through the Enlightenment to the thought-world of Plato’s guardians. And he is clearly meant to be a thoroughly pernicious, subversive force, the deadly ivy on the native oak, which in turn symbolizes the authentic Europe:

But Ivywood, Lord Ivywood,

He rots the tree as ivy would.

He clings and crawls as ivy would

About the sacred tree.

But Ivywood, Lord Ivywood,

He hates the tree as ivy would.

As tire dragon of the ivy would

That has us in his grips.

Ivywood moves neatly from representing the voice of Fabian or progressive idealism—the world of H.G. Wells or Bertrand Russell—to becoming a tool of organized Islam, which uses him as a convenient front man for the annexation of England. In the multicultural dream that he advocates, the two religions will merge to form a new synthesis (“Something called Chrislam, perhaps,” glowers one disenchanted rebel). A Cross-Crescent hybrid appears on St. Paul’s Cathedral (the “Croscent”), and the Koran is to be integrated into a revised Bible.

Increasingly, it becomes obvious that prohibitionism and progress are Trojan horses for full-scale Islamicization. Though ostensibly an account of the triumph of progress, the plot resolves itself into a struggle between the only two intellectual forces that have ever mattered in the world—those who accept the Incarnation and those who reject it. The two forces clashed bloodily at Tours in 732, at Constantinople in 717 and again in 1453, and now they meet once more on a battlefield in a not-quite-yet England. “There, encamped in the English meadows . . . was something that had never been in camp nearer than some leagues south of Paris, since that Carolus called the Hammer broke it backwards at Tours.” In the last great battle, the struggle that saves England for the Incarnation, Lord Ivywood stands on the field under the banner of Islam, dressed “in a uniform of his own special creation, a compromise between the Sepoy and Turkish uniform.” All pretense of humanistic secularism is gone. After the Muslim forces are routed, he retreats into a baffled insanity, as Christendom gains the field. He is lost in the fantasy world of those who try to create Utopias without taking account of human and divine realities. He cries, “I have gone where God has never dared to go. I am above the silly Supermen as they are above mere men.”

The Flying Inn can be seen less as a novel than as the creation of a whole mythical world. I here take the word “myth” as a child once defined it: a story that is not true on the outside, but is true on the inside. ‘The story’s characters have the pristine truth of mythology, speaking words that we can hear all around us in everyday life: They are archetypes. Reading Lord Ivywood’s speeches, we can hear precisely the sentiments about religion that surface so frequently in the media today, about the necessity for a wide-ranging relativistic tolerance that must be applied to every religion under the sun—except Christianity. As Ivywood puts it, “Ours is an age when men come more and more to see that the creeds hold treasures for each other, that each religion has a secret for its neighbor, that faith unto faith uttereth speech, and church unto church showeth knowledge.”

We think equally of Ivywood when we hear modern paeans to the glorious lost civilization of medieval Islam—that heroic, tolerant, proto-Enlightenment world that supposedly stood in such magnificent contrast to the horrors of European Christendom. Said Ivywood: “Islam has in it the potentialities of being the most progressive of all religions; so that a century or two to come we may see the cause of peace, of science, and of reform supported by Islam.” While we might be troubled by aspects of the history of Islam—the pervasive despotism, the mass slave-trading, the corruption—we have to understand that (as Ivywood declares) these notions are products of “the illimitable pro-Christian bias with which the history of those Eastern tribes is told in this country.” The very symbol of Islam was the Crescent, a sign of growth (and not the Cross, the death-symbol favored by other religions now out of favor). Ivywood felt that every Western progressive could agree with this sign and all it implied, tire “principle of perpetual growth towards an implied and infinite perception.” Ivywood has countless modern imitators. For millions today, the sublimest religious truth is to be found not in the native Christian tradition, but in the works of Islamic mystics, of Sufi masters like Rumi, though in New Age forms shorn of much of their overt Muslim content.

Ivywood stands triumphant whenever a contemporary politician or academic boasts how non-Christian immigration will transform our failed Western nations into Utopian multicultural societies. When Chesterton wanted to introduce Islam as a factor in his story, he had to concoct a fantastic story of how England forged a diplomatic alliance with the Ottoman Empire. Today, such a stretch is utterly unnecessary, given the migration of mass Muslim populations across Europe and, indeed, into the United States. There are now three million Muslims in Germany, two million in France, at least a million in Britain, and perhaps 750,000 in Italy. The most thorough transformation has been in French cities like Marseilles, which have acquired a strongly North African flavor. Muslims make up around a fifth of the population of Vienna, a proportion that has more than doubled just since the late I980’s. Europe as a whole has some 15 million Muslims, many of whom are of ancient stock, particularly in southeastern parts of the continent. Meanwhile, I can only speculate how many Europeans of Christian heritage still espouse the doctrine of the Incarnation, but I imagine the proportion is tiny. The ivy has spread far.

Many things that Chesterton portrayed, seemingly ludicrously, as part of the Turkish invasion of England have appeared in the West as components of multiculturalism. In September, the U.S. Post Office issued its first stamps commemorating Islam, complete with Arabic inscription—though these items became a little scarce a week or so later, when other Muslims notoriously succeeded in obliterating the World Trade Center. Honestly, I wonder why the word “Ivywood” has not entered our popular speech, commemorated in the same way as “boycott” or—perhaps a better analogy—”quisling.” So do not rule out the appearance of the Croscent ere too long—not to say Chrislam.