In a time when biologists write books such as “The God Delusion” and 93 percent of the members of the National Academy of Sciences reportedly embrace atheism or agnosticism, it’s easy to forget that science was once the province of the faithful: Newton, Copernicus, Mendel, Max Planck, Einstein.

But Lauren Grodstein hasn’t forgotten, and what she’s fashioned in her smart, assured third novel, “The Explanation for Everything,” is a gripping tale of a biologist who finds himself approaching midlife and suddenly finding faith. Andy Waite, a widower and single father, is teaching evolutionary biology at a small New Jersey college when Melissa, a young evangelist, asks him to advise her independent study on intelligent design. Hopeful he can show her the Darwinian light, Andy agrees, igniting a debate between atheism and Christianity, evolution and creationism, that simmers through the novel.

Grodstein is both smart and respectful; she plays fair with her arguments. Just as the novel’s Christians observe the world intent upon sustaining their beliefs, so do the scientists. Andy conducts research, “dosing more mice and then dissecting them in order to prove his ever more unprovable theory that alcoholics were resistant to behavioral changes.” Andy is determined, we soon learn, because his wife was killed by a drunk driver, whom Andy is intent on keeping in jail.

Although the book is, on the surface, an intellectual novel, it is much more doggedly the tale of Andy’s recovery as a widower. The atheist-
creationist debate between Andy and Melissa is soon quieted as Melissa begins babysitting Andy’s daughters and a risky but mostly chaste romance flourishes. Intellectual conversation takes a back seat to emotional connection, Andy appears to find God (somewhat rapidly), and the story races forward on the narrative fuel of his new infatuation, lingering grief and his morally questionable desire for vengeance.

Which is just fine — because Grodstein’s real gift is her emotional precision. Andy’s letters to the parole board petitioning against the release of the man who killed his wife are some of the most emotionally raw letters available between two covers. The intimate scenes between Andy and a single mother who’s a recovering alcoholic are deeply moving. And Andy’s touching struggle to raise two motherless daughters and deal with his intellectually vapid students renders him a sympathetic protagonist, despite his occasional inertia. “All his life he’d been like that,” Grodstein writes, “forgoing the small good decision in favor of entropy, letting the chips fall where they may.” It’s worth noting, too, that the novel’s depiction of Exton Reed College is superb; with a single dinner party and a few student encounters, Grodstein captures a small school’s intimacy and claustrophobia.

Where the novel slackens is in the relationship between Andy and Melissa. Melissa is both nemesis and catalyst to Andy, but because of her youth (she is 21, Andy 41) and her monochromatic emotional landscape (her sweetness and certainty at times veer toward simplicity), she is neither a worthy adversary nor partner. While this is intentional, their scenes, which occupy the bulk of the novel’s middle, lack the life and luster of Andy’s other encounters — a heart-rending moment with the mother of the drunk driver, for example, or even the tangential but mesmerizing story of Andy’s unhinged mentor at Princeton, who essentially destroys a life in the name of science.

The most fascinating aspect of Grodstein’s tale is the degree to which characters’ daily emotions are shaped by their worldview. Finding or losing God proves to be an equally destabilizing tectonic shift, and this novel is full of them — some plausible, some less so — but their cumulative force will leave you happily unsteady, and moved.

Vanderbes’s third novel, “The Secret of Raven Point,” will be published in February.


By Lauren Grodstein

Algonquin. 338 pp. $24.95