William Lane Craig has faced Richard Dawkins in a debate about the existence of God only once. It was on November 13, 2010—part of La Ciudad de las Ideas, a three-day, all-star conference in Puebla, Mexico. The setting there suited the drama of the occasion; a podium stood at the center of a full-size boxing ring, which the debaters mounted in turn. The event’s organizer, the Mexican television personality Andrés Roemer, later described them to me as “gladiatores mentales” in “a war of intelligence and arguments.” There were three men on each side. Three thousand people watched live in the audience, and as many as ten million saw it on TV, especially when it was rebroadcast after the boxing match the following night between Manny Pacquiao and Antonio Margarito.

Richard Dawkins, whose name many people are likelier to know than Craig’s, was once professor of “the Public Understanding of Science” at Oxford. He wrote a parade of well-regarded popular books on evolutionary biology. In retirement, he has turned his attention to—or, against—religion. His book The God Delusion was a best-seller when it was published in 2006 and has continued to sell well. It’s caustic, merciless, and engrossing. Between its reflective silver covers, with a bit of science and plenty of bombast, Dawkins announces that God’s existence is so improbable, and so dangerous when believed, that we would be better off banishing the thought of it altogether.

William Lane Craig, on the other hand, is an evangelical Christian philosopher with two PhDs, which he wields masterfully in formal public debates, aided by eight years of debate-club training in high school and college. Dawkins’ fellow “New Atheist” author Sam Harris remarked, while debating Craig at Notre Dame in 2011, that he is “the one Christian apologist who seems to have put the fear of God into many of my fellow atheists.”

In the ring, each gave his usual stump speech, as he had countless times before. Craig outlined in quick form his favorite arguments for believing that God exists; Dawkins denounced questions of ultimate meaning as “silly.” Their speeches echoed proofs of one kind or another that have been circulating since the ancients, sung to the tune of modern science. At the end, they and the other gladiatores gathered for a photo-op.

Their antipathy, however, is real. A few days after the debate, I happened to see Craig at an evangelical philosophy conference, where he regaled his colleagues with stories of Dawkins’ awkward repartee with his best impression of the don’s accent. When I later met Richard Dawkins and told him that I had been reporting on William Lane Craig, he turned irritable. “Why are you publicizing him? Why are you publicizing him?” Dawkins demanded of me. “Whose side are you on?”

I was there as a reporter, just asking questions. I wasn’t sure I wanted to be on either side, really, and I don’t think I was alone in that.

The boxing ring in Puebla was only an especially caricatured version of what has become commonplace on college campuses and in churches all over: a formal debate about the existence of God. Debates like these bring in the ambivalent, the undecided, the apathetic, and the true believers alike. If nothing else, it’s a good show. A debate at a college campus catches students when they’re open and vulnerable to new ideas, away from home for the first time and freer to think on their own. Each side claims to possess proof, or something close to it. Amid the tumult of adolescence and the liberal arts, it holds the promise of a clear victor, a quick fix.

In these debates there can be only two sides, with nothing in between. The way to win is to take a strong, steady position and stick with it. Unlike doing actual philosophy, debating is no time to try to learn from the person you’re up against, or to be forthright about the weaknesses of your own position. Those who hope to sway the audience by making graceful concessions, or by finding common ground in the middle, are only asking to get clobbered. One side must be right, and the other must be wrong.

It’s too bad. Using the long tradition of so-called proofs about God as an academic performance, or as blunt instruments for culture-warring, means missing out on the most worthwhile stuff they have to offer. The proofs are arguments for a particular claim, it’s true. But they’re also meant to invite us into fresh modes of thinking. They need not be so black-and-white—or, in the boxing ring, win-or-lose. The real question a proof about God was created to address may be not be simply whether or not God exists. More often, it’s something more interesting: What do we mean by God? And what can be achieved with proof?

*

Some will probably object to me using the word proof at all; they’d prefer something humbler, like demonstration or argument. But proof fits what I’m talking about like no other word does. Sure, the 1933 Oxford dictionary’s definition is part of it: “evidence sufficient (or contributing) to establish a fact or produce belief in something.” But historically the word has had more to do with an experience, a crucible, as in having proved oneself. Bakers proof bread, printers print proofs, and militaries have their proving grounds. A jacket is waterproof if it can endure the test of rain. Proof is more than a mathematical statement; it has meant a process of survival or maturing. It’s not merely rational, but a process of development that calls on the whole person.

One of the truest stories I know of about what proofs have stood for over the centuries is in a work of fiction. Hayy Ibn Yaqzan was written in twelfth-century Grenada, Spain, by a Muslim philosopher named Abu Bakr ibn Tufayl. The title is also the protagonist’s name, which means “Alive, son of Awake.” The book happened to be a pithy summary of what philosophers at the height of medieval Islamic civilization longed for with their proofs, and what they thought proofs could accomplish. The reappearance of religious proofs later on in Christian Europe owed a lot to what happened in the Muslim world at that time. Hayy Ibn Yaqzan itself eventually became the inspiration for Daniel Defoe’s Robinson Crusoe.

It’s fitting, I think, that one of the world’s first philosophical novels can’t decide between science fiction and plagiarizing scripture; Ibn Tufayl gives two possible explanations for how his hero came to be, from infancy, the only human being on his entire island. First, we learn that Hayy comes about through spontaneous generation, a convergence of natural forces explained in poetic pseudoscience: sunlight mixed with island mud. But Ibn Tufayl realizes that not everyone will think this plausible. Then, so as not to obstruct the narrative at its outset, he offers a second alternative: Hayy is born elsewhere under suspicious circumstances and set adrift in the sea by his mother—like Moses in the Bible and the Qur’an, entrusted to God’s care. Natural or mythic: take your pick.

Whichever story of Hayy’s origin you do choose, his journey begins in earnest at infancy. A doe finds him, adopts him, and suckles him into childhood. He grows up at her side, imitating her and the other animals on their island. The doe teaches him to eat wild fruit and drink from streams. She keeps him warm in the cold. He learns no human language, but he can mimic bird-calls and grasp their meaning.

By his seventh year, Hayy starts realizing that there’s something different about himself. He learns to use sharpened sticks to ward off hostile creatures. Troubled by his private parts, he covers them and eventually makes himself a costume of eagle feathers.

After the doe’s death, Hayy studies and dissects other animals. He moves into a cave, discovers fire, and learns to cook meat. At twenty-one years old, he begins speculating on abstractions like variety, unity, the elements, size, forms, and measurement. Observing the stars, at age twenty-eight he charts their movements, and they lead him to infer a hidden unity. The defining moment for Hayy comes at age thirty-five, when he becomes convinced of the existence of a supreme being. Nothing is the same afterward. He is no longer alone.

The proof doesn’t come all at once. First, with echoes of Plato’s Timaeus, Hayy concludes that anything that comes into existence must have a cause, beginning with a creator who made the world according to the blueprints of eternal, perfect forms. He also marvels at the order of the natural world. Like Aristotle, looking up at the stars, he reasons that everything in motion must have been moved by something else; since the sequence can’t go on to infinity, there has to be a first mover. Each of these observations seems to point at the same thing, though even if he could speak he doesn’t know its name. The book’s Muslim readers, however, did. This was God—Allah—more or less like the God of Islam.

Hayy’s speculations start to get even more adventurous, beyond just repeating the ancients. He was especially interested in the idea of something existing necessarily, by virtue of itself. Aristotle had used this concept to argue for an eternal universe, but for Muslim philosophers it seemed to allude to their God.

To us, I know, it can sound like a bunch of strange medieval terminology. But bear with me.

Nothing has to cause a necessary thing to exist. It just exists, and it has to. The universe wouldn’t make sense if it didn’t, like a painting with no surface. Other things exist contingently, like a picture that emerges from the paint, having been caused by something else. Contingent things can cause contingent things, but they all depend on what is necessary.

Hayy collects these concepts into a proof, along the lines of the argument that Aristotle had once made from motion. An infinite regress of contingent things causing other things is absurd. There must, at the end of the line, be a necessary being, one that depends on nothing else to account for its existence.

This route to God, tracing the logic of Aristotle, generally appealed to Muslims, as it did to Christians and Jews, except for one big problem: Aristotle’s God presides over an eternal universe. That would contradict the first verse of Genesis, for instance, as well as passages about creation throughout the Qur’an. The God of scripture created the universe with a beginning in time, out of nothing. The debate about proofs for the existence of God in the medieval Islamic world always hinged on whether to insist on creation from nothing, or to follow Aristotle back through eternity; you had to choose one or the other.

This problem, for this time and place, was philosophy at its most dangerous. The Almohad dynasty that Ibn Tufayl lived under had a brutal policy of intolerance for whatever didn’t fit their literalistic kind of Islam. Ibn Tufayl—and therefore his character Hayy—had to be careful. Even after discovering the existence of his necessary being, the question of the origin of the universe plagued him for years on end. This was the question that wouldn’t lead him to an answer, and it wasn’t for lack of trying.

With plenty of time to spare on his lonely island, Hayy’s mind thinks its way to a proof of the first cause, and to a being necessary-by-virtue-of-itself with an eternal universe. But, in light of his proofs, he can’t decide which story is really true—eternity or creation. He has no revelation or ancient authorities to incline him one way or another. But what he finally discovers is that, actually, the implications are the same. A God worthy of worship awaits him at the end of either proof: a cause without a body and a perfect, unchangeable ground of being. It dawns on Hayy that, no matter what, he can be sure there is a God. That’s assurance enough for him. The world’s biggest problem is no problem at all.

This kind of clever reconciliation, of negotiating a high-stakes dispute, is a common practice in the history of proofs. When the Catholic saint-to-be Thomas Aquinas listed his “five ways” of demonstrating God’s existence, it’s doubtful that he was trying to convince atheists—or that he knew any atheists to convince. More likely, like Ibn Tufayl, he was trying to show the reactionary society he lived in that the theories of ancient foreigners weren’t as scary as they might seem. Today, Aquinas is often presented as a patron of stale orthodoxy, but in his time he was anything but.

Similar tasks of reconciliation carries on today in unlikely places. Many are quick to dismiss creationists and supporters of intelligent design alike as affronts to science, as they often are. But critics neglect to notice how these movements also seek to move fellow believers from utterly dismissing modern reason to at least considering it in their own way. In the midst of a culture war, proofs become a compromise, a negotiation, a balancing act.

*

Alone on his island, and blissfully ignorant of medieval theological disputes, Hayy Ibn Yaqzan’s proof means much more to him than politics. Proof possesses him. Ibn Tufayl relates, “By now thought of this Subject was so deeply rooted in his heart that he could think of nothing else.”

Hayy gets better and better at making the periods of bliss last longer and longer. He learns that it helps to spin in circles—like a Sufi dervish, or pilgrims circumambulating the Ka’ba in Mecca, or the stars overhead. His visions take him through the celestial spheres, and he sees countless faces all praising God in unison, then the torment of souls who don’t heed their divine source. This might sound to us like a mescaline trip, but its cause is proof and proof alone. The whole cosmic order comes to him on his island. Once again, Hayy’s experience reflects the real-world tradition of proof-seeking.

Among the most famous of history’s proofs for God is the ontological argument of Anselm of Canterbury, an 11th-century Christian monk. Anselm knew something of Hayy’s ecstasy. Anselm’s biographer recorded that, upon discovering his own proof, “a great joy and jubilation filled his inmost being.” The proof is simple but beguiling: the idea of God is so perfect that God must exist. A non-existing God would be less than God.

Anselm, like Thomas Aquinas, doesn’t actually seem to have been trying to convince anyone that God exists; there weren’t enough atheists around to bother. Anselm’s proof was controversial among fellow monks because of the closeness with God Anselm claimed he was able to access through reason. Tellingly, almost the same language he used to describe his concept of God—“nothing greater can be conceived”—appears in a letter to a friend years earlier as a gushy compliment. Just as the letter expressed affection for his friend, the proof was an ode to his God. He originally composed it in the second person, addressed lovingly to the God being proved.

Hayy Ibn Yaqzan, too, is a junkie for divine company. “He has gained an understanding as unshakable as that of an old friendship,” relates Ibn Tufayl. Hayy’s ecstasies eventually become so intense that he loses interest in living entirely: “Hayy longed that God—glory to Him—would ease him altogether of his body.” But his body perseveres, and the story continues.

*

It turns out that there is another island nearby, one not so lonely. It is populated with people who have received news of God’s prophets and made a religion out of it. Where Hayy has only hard-won, direct experience, those on this other island teach each other about the necessary being with symbols and laws. Or at least they try.

There is a man on this other island named Absal. Having had a small taste of mystical adventures like Hayy’s, life in society doesn’t satisfy him anymore. He sets off into the ocean in search of solitude, and he lands on Hayy’s island.

At first, when they see each other, Absal runs away. But Hayy chases him down and catches him, and they become friends. Absal teaches Hayy language, and Hayy reciprocates by talking about his visions. Absal explains how religion works back on his island. There are certain basic practices: faith, prayer, alms, fasting, and pilgrimage. He describes the stories of heaven and hell, of judgment and resurrection—stories that came to earth through a messenger. Basically, he teaches Hayy about Islam.

When Absal tells him about popular religion, however, with all these trappings of ritual and law, Hayy doesn’t exactly see the point. Why bother? Why doesn’t everyone just live in perpetual, rational ecstasy like he does? He needs to see it for himself.

They sail for the other island, and on arrival Hayy starts preaching about what he has discovered from his thinking and visions. People gather around him and listen at first out of curiosity, but their attention hits a limit. Those who understand a little get stuck in arguments and confusion, while the rest understand nothing. Most are interested in religion only so far as it can win them possessions and power over each other. His teachings cause chaos.

“Hayy now understood the human condition,” writes Ibn Tufayl. “He saw that most men are no better than unreasoning animals.”

Frustrated, Hayy and Absal decide to return to the island Hayy came from, where they can have their ecstasies in peace. That’s where their story ends. But their confrontation with civilization replays again and again in the history of proofs.

Five hundred years after Anselm discovered his ontological argument, much the same kind of proof was adapted in a very different way by Benedict Spinoza, a seventeenth-century Amsterdammer Jew who had been banished from his community for his unorthodox opinions. Spinoza followed Anselm in analyzing the concept of an infinitely perfect being. It would be “absurd,” Spinoza concluded, for such a being not to exist. But there was a twist: The result he came to was a God that is simply the totality of the universe—“God, or Nature,” as he put it.

This, to many readers, was blasphemy. Such a God would be no God at all. They labeled Spinoza an atheist, but he insisted otherwise. In fact, like Hayy, he was so enraptured with his proofs that a later poet would dub Spinoza “the God-intoxicated man.” To him, the point wasn’t whether or not God exists, but what kind of God one means. Through proof, he proposed a universe that could be both infused with divine perfection and receptive to the scrutiny of science. Spinoza’s ideas made him an exile for life, among Jews and everyone else. Coming up with proofs generally doesn’t make one popular.

*

For all our latter-day efforts to domesticate them with abstraction and polemic, the great proofs about God have been political acts, and transgressive experiences, and feats of innovation. The search for proof can set one apart from the world. But as an escape from the world, it is doomed to incompletion.

Women, looking upon this mostly-male tradition of proofs about God, have tended to recognize right away that it is far from solely a matter of the intellect. They’ve seen in the proofs narcotics, and sex, and a means of exclusion in disguise.

Annie Besant, later to become a famous Theosophist, once referred to God-proofs as “puffing divine smoke rings,” a thing that men do “over the walnuts and wine after the ladies have left.” Literary critic Susan Sontag surmised, “Jerking off the universe is perhaps what all philosophy, all abstract thought is about: an intense, and not very sociable pleasure, which has to be repeated again and again.”

In the 1990s, feminist scholar Nancy Jay argued that sacrifice rituals across cultures help create a male-only lineage that writes women out of the history and power structure of a tradition. The same might be said of arguments about the existence of God. By turning to the lineage of proofs, men have sought to cover over the real sources of their religious belief: the whispers of their mothers, the rituals of their communities, the need to feel loved. Through the experience of trying to prove, thinkers have sought to escape the bonds forged in other kinds of experience.

“Insofar as I am a thinking thing,” René Descartes once wrote, it was not his parents “who in any way brought me into being.” Yeah, right. The character of Hayy Ibn Yaqzan similarly represents an ideal that seems drenched in predominantly male impulses: purely rational, utterly unencumbered on his island, with no need for anyone else.

The history of religious proofs is a many-sided story. I hope you’ll agree that this is a worthwhile inheritance, though too often we’ve adopted its worst tendencies while ignoring the best. Until we realize that arguments about something like the existence of God speak to more than just the intellect, and to more than just a yes-or-no question, we can expect that the same old debates will keep coming back without satisfying us—in Sontag’s words, “again and again.”

Adapted from God in Proof: The Story of a Search from the Ancients to the Internet.