Mike Terry, Deseret News
The Davis County School District participates in "A Night with C.S. Lewis" at Northridge High School, March 30, 2006.

A central theme in C.S. Lewis' autobiographical book "Surprised by Joy" — and the obvious source of its title — is what he terms "Joy."

Yet Lewis struggles to convey what he means. "Longing," he calls it, sometimes using the evocative German synonym "Sehnsucht." He describes fleeting instants when, encountering a landscape or phrase or musical passage, he suddenly and unexpectedly "desired with almost sickening intensity something never to be described." "It was a sensation, of course, of desire; but desire for what?" "Before I knew what I desired, the desire itself was gone, the whole glimpse withdrawn, the world turned commonplace again, or only stirred by a longing for the longing that had just ceased." Of his earliest such experience, he writes, "It had taken only a moment of time, and in a certain sense everything else that had ever happened to me was insignificant in comparison."

Lewis' first encounters with "Joy" often involved Norse mythology and, eventually, the music of Wagner: "Pure 'Northernness' engulfed me: a vision of huge, clear spaces hanging above the Atlantic in the endless twilight of northern summer, remoteness, severity." Yet he eventually realized that his yearning wasn't really for things Norse and Northern, but for something beyond them.

Joy, in Lewis' sense, is "an unsatisfied desire, which is itself more desirable than any other satisfaction." Though it resembles them in the sense that "anyone who has experienced it will want it again," it's distinct from happiness and pleasure. Indeed, he describes it as "inconsolable," a "stabbing," a "pang" and a sense of "loss," observing that "it might almost equally well be called a particular kind of unhappiness or grief. But then it is a kind we want. I doubt whether anyone who has tasted it would ever, if both were in his power, exchange it for all the pleasures in the world." "All Joy reminds," he says. "It is never a possession, always a desire for something longer ago or further away or still 'about to be.'" It always "implies the absence of its object."

When I first read Lewis on "Joy," I knew immediately what he meant.

He wondered whether others shared his experience. I have.

The eminent Austrian-American sociologist Peter Berger regards northern Italy's extraordinarily beautiful Lake Como as the most powerful argument for the existence of God. I would quibble about the specific location, but I understand.

Certain alpine landscapes — in the Canadian Rockies, in Italy around Cortina d'Ampezzo and the Dolomites, and, pre-eminently, in Switzerland's Berner Oberland (where I served as a missionary) — have often awakened in me an aching and almost overwhelming sense of transcendence.

I know how it feels to want to possess them in a way that they simply cannot be possessed — though what I've just written doesn't really capture the feeling. What would it mean to "possess" the Bernese Alps? How, Lewis asks, can anybody "possess" the "Idea of Autumn" (as, in one such transient moment, he deeply desired to do)?

I can no more define the experience than Lewis could. I'm confident, though, that some readers will recognize it.

The desire is, in a sense, entirely vain. "Stay a while!" Goethe's Faust implores one rapturous but passing moment. "You are so beautiful!" But the moment doesn't stay. Everything is transient.

Still, I believe that such experiences offer powerful religious meaning to those who've had them. They are, I think, "stabs" of "divine homesickness," a yearning for something unspeakably and unchangingly beautiful, good, and holy. Eliza Snow reminisced that, even before Mormonism, "ofttimes a secret something whispered, 'You're a stranger here,' and I felt that I had wandered from a more exalted sphere." William Wordsworth perceived "intimations of immortality" (and of a premortal existence) in nature. The Persian poet Rumi compared the human soul to a reed; the plaintive sound of reed pipes expresses the reed's longing for its lost home in the reed bed just as we yearn for the divine home from which we've been severed.

Reasoning that, since ordinary desires (e.g., for food, water, air, sex or companionship) can always be fulfilled (at least potentially), Lewis argued that the yearning he called "Joy" also promises the possibility of satisfaction — if only in another world.

"You have made us for Yourself, Oh Lord," wrote St. Augustine in the first chapter of his "Confessions," "and our hearts are restless until they rest in Thee."

Daniel C. Peterson is a professor of Islamic studies and Arabic at BYU, where he also serves as editor in chief of the Middle Eastern Texts Initiative and as director of advancement for the Neal A. Maxwell Institute for Religious Scholarship. He is the founder of MormonScholarsTestify.org.