Last summer, I wrote about my run-in with a rabid skunk, which reinforced my disbelief in a benign, all-powerful God. If such a God exists, why does He allow some people to suffer so much, through no fault of their own? Like people killed by rabies or leukemia, a tsunami or an earthquake? This is the old problem of evil. My inability to answer this riddle keeps me from adhering to Catholicism—the faith in which I was raised—or any other religion.

But I am not an atheist, either, and here's why: The flip side of the problem of evil is the problem of beauty. If there really is no God, if the world was not in some sense designed for us, why is it so heartbreakingly lovely?

The British biologist and arch-atheist Richard Dawkins flicked at this issue in Climbing Mount Improbable (W.W. Norton, 1997). Dawkins recalled driving through the countryside with his six-year-old daughter when she enthused over some "pretty" wildflowers. When Dawkins asked what she thought wildflowers are for, the innocent child replied, "To make the world pretty, and to help the bees make honey for us." Dawkins—bless his hyper-rational heart!—mused: "I was touched by this, and sorry I had to tell her it wasn't so." (I actually laughed out loud the first time I read this passage. Imagine what Dawkins would say if his daughter asked about Santa Claus!)

Dawkins pointed out that his daughter's logic resembles that of Christian fundamentalists who claim that God created the AIDS virus to punish sinners. True enough. But Dawkins never adequately explained why nature evokes such a profound aesthetic response in us. His fellow biologist Edward O. Wilson gave it a shot. Wilson suggested that natural selection might have instilled in us a "biophilia," or reverence for nature, that benefits both us and those creatures with which we enjoy mutually beneficial relationships. But why do we respond to so many things—butterflies, starfish, rainbows, sunsets—from which we extract no tangible, utilitarian benefit?

Another famous atheist, the physicist and Nobel laureate Steven Weinberg, eloquently explained his lack of belief in Dreams of a Final Theory (Vintage, 1994). Weinberg had no complaints about his own life. He had been "remarkably happy, perhaps in the upper 99.99 percentile." But he had seen "a mother die painfully of cancer, a father's personality destroyed by Alzheimer's disease, and scores of second and third cousins murdered in the Holocaust."

Weinberg rejected the proposition that evil is the price we pay for our God-given free will. "It seems a bit unfair for my relatives to be murdered in order to provide an opportunity for free will for the Germans," he noted, "but even putting that aside, how does free will account for cancer? Is it an opportunity of free will for tumors?" Good questions. But then Weinberg added this line, which, like Dawkins's recollection of how he disillusioned his daughter, made me smile: "I have to admit that sometimes nature seems more beautiful than strictly necessary." Talk about an understatement!

My friend David Rothenberg, a philosopher at the New Jersey Institute of Technology, is, I think it's fair to say, obsessed with the problem of beauty. He has been poking, prodding and pondering the problem for many years. He has trekked around the world to interview scientists who, in one way or another, study beauty (even if they shun that term) and attempt to explain it, if not explain it away. His research has led to a trilogy of marvelous books: Why Birds Sing: A Journey into the Mystery of Bird Song (Basic Books, 2006); Thousand Mile Song: Whale Music in a Sea of Sound (Basic Books, 2008); and, released just last month, Survival of the Beautiful: Art, Science, and Evolution (Bloomsbury).

His new book considers not just music—in which Rothenberg, as a musician, has a special interest—but beauty in all its manifestations, and especially visual art, whether Paleolithic cave paintings or the ethereal, sculptures of bowerbirds. Rothenberg does all the things that conventional science writers do. He interviews experts in their labs and in the field, weighs the evidence for their theories, offer his assessments and so on. But he also engages with his material in utterly original ways. In an attempt to understand the music of other species, he has played his clarinet with a lyrebird in Australia and with a humpback whale in Hawaii.

Rothenberg, whom I interviewed on Saturday for, argues passionately that we are not the only species with an eye and ear for beauty and a compulsion to create. He is dissatisfied with theories that attempt to explain beauty in strictly functional, evolutionary terms, as a mere side effect of mating or communication. These theories, he asserts, do not do justice to the richness and complexity of art, whether human or inhuman. He proposes that a laughing thrush lets fly a new aria and a satin bowerbird adorns his sculpture with blue flowers not just to attract mates but for the sake of beauty itself, for the sheer joy of creation, just as human artists do.

In his new book, Rothenberg proposes that many species might be shaped by a principle that he calls "aesthetic selection." But he doesn't pretend that this idea solves the problem of beauty any more than sexual selection or other more mainstream hypotheses do. He's less interested in solving the problem—in reducing it to some underlying, mechanical process—than in celebrating it. He dances around it, writes a poem about it, paints a picture of it, plays a duet with it, and he thereby illuminates the problem of beauty more than any mere theory can.

Image courtesy Bloomsbury Press.