A proof for God’s existence came to Anselm in the dark of early morning, under the solemn sound of psalms, echoing against the stone walls of the church. It was the year 1077, at the monastery of Bec in what is now northern France. Anselm was happy. “The grace of God shone on his heart, the whole matter became clear to his mind, and a great joy and jubilation filled his inmost being,” his friend and biographer Eadmer would later write.

For Catholics, Anselm is a saint, a theologian and bishop who defended the Church from the encroachment of kings. For philosophers, he’s the inventor of an ingenious and still-controversial artifice of abstraction. The great 20th century mathematician Kurt Gödel had this to say about him:

Reproduced from “Kurt Gödel, Collected Works: Unpublished Essays and Lectures”

(New York: Oxford University Press, 1995), p. 431

It was the attempt to succeed at both Catholicism and philosophy that first put Anselm on my required reading list. But the person I found in his pages was neither bishop nor logician so much as an effusive confidant.

It was the summer after I finished college, and I was passing a few weeks at home in Virginia before moving to California. I stretched out on the carpet floor of my old bedroom in the basement, reading Anselm’s “Proslogion,” finally, for the first time. Dangling on the lonely precipice between a certain past and a long, uncertain drive west, I thought back on the bizarre choice I’d wandered into, almost four years earlier, when I got myself baptized a Catholic. Now, moving far away, with the chance to start over, I started to wonder if I believed in any of it anymore. Did I still even think that God exists?

Anselm’s proof rained on me a drop of consolation. It filled my head enough to cover over the hollow low in my stomach.

For years before his insight, Anselm had been searching for a new way of understanding God’s existence. He knew a handful of familiar arguments, but in the end, they were too piecemeal to satisfy him. None seemed worthy to describe the God of his love and his longing. The frustration tormented him day and night, distracting his attention even from prayers. “Gladness was hoped for,” he remembered, “and lo! a source of frequent sighs!”

All the other proofs he knew depended on observations about the world: the order of nature and the physics of cause and effect. Anselm, instead, gunned straight for the dream of the Greek philosophers: a God of pure, abstract reason, a secret God of the inner life, which the wise can recognize everywhere they go, sufficient unto itself. Aristotle called it the self-thinking thought.

The proof, which would come to be called the ontological argument, purports to demonstrate the existence of God from ideas alone: the concept of a God that doesn’t exist wouldn’t be much of a God. A true concept of God, “a being than which nothing greater can be conceived,” would have to be a God that exists. Therefore, God exists.

Nathan Schneider

It is a masterpiece of mental hedonism, an idea that satisfies itself. And Anselm loved his proof. “I thank thee, gracious Lord, I thank thee,” he gushed. “Because what I formerly believed by thy bounty, I now so understand by thine illumination.” He had found not just an argument, but a communion, a glimpse of the invisible Ever-Present.

I let the rapture in his proof take hold of me. For passing moments, lying on my back with the book in my hands, I came to sense the whole vastness of a God wrapped around my little mind, like a lonesome asteroid must feel touching the gentle infinity of space. Then, always, my mind wandered elsewhere and I forgot some movement of the logic. The whole thing dissolved away, along with the sense of certainty. I started to remember the echo of Kant’s devastating complaint against Anselm: existence is not a predicate. God seemed to disappear.

But I read on. I was reminded it wasn’t God’s existence that plagued Anselm — of that, he had no doubt — it was the phrasing. Modern arguments and evangelists and New Atheists have duped us into thinking that the interesting question is whether God exists; no, what mattered for Anselm was how we think about God and about one another.

When Anselm discovered his proof, he was still a precocious young monk in the quiet of a monastery. He loved silence and contemplation, yet constantly he reached out beyond it. The letters he wrote to far-flung friends in those years overflow with longing, in language eerily like what he used to describe his proof. “Everything I feel about you is sweet and pleasant to my heart,” Anselm wrote to another monk named Gundulf. “Whatever I desire for you is the best that my mind can conceive.” His passion in friendship is so palpable, and so unusual for its time, modern scholars have wondered whether these relationships were entirely celibate. (They probably were.)

The God he conjured in proof he had learned from his friends. The fullness, the absence, the solitude and the hunger — I recognized myself. The answer I found in his proof is no answer at all, no truly abstract, autonomous assurance that I can have all to myself. I have to stitch it out of memories, hopes and loved ones, as he did. It is no self-thinking thought; it’s a pleasure built out of language and sharing.

Setting off for a new place, I was saddled in the past, in what I had been and done. My conversion, and with it God, is not a thing I can live down, but something I’ll always have to live in, through and around. The very fact of it, that it happened at all, is a proof for its own ongoing existence.

Nathan Schneider is editor of the online religion magazine Killing the Buddha. His writing on the intersections of religion and reason has appeared in The Boston Globe, The American Prospect, The Guardian, Religion Dispatches, Seed and elsewhere.