As both a theoretical physicist and a best-selling novelist, Alan Lightman would seem unusually qualified to write a novel such as “Ghost” (Pantheon, 256 pages, $23), which depicts the conflict between pure science and belief in a “world underneath.” The result is both more and less than one would hope for: a novel that feels oddly stunted, but also admirably clinical and empathetic in similar measures.

Mr. Lightman’s protagonist is a divorced and disappointed man named David Kurzweil, who has taken a job at a mortuary after being abruptly laid off from the bank where he toiled for much of his adult life. The mortuary (“Funeral home. That’s the term we prefer.”) is a drab place, described by Mr. Lightman in perfunctory sentences without resonance or menace, as are the preparations of corpses for display: “Some of the organs faintly pop as they are punctured. … He packs the anus with cotton.” This feels like a firm assurance by Mr. Lightman that despite his novel’s title, he intends to explore death and what follows with as little sentiment as possible.

One night in the “slumber room” — where bodies are stored — David glimpses something unsettling, which he takes as a supernatural event. Or maybe he doesn’t. He can’t say for sure. But when he tells a few other people about it, they seem pretty sure, and soon a local newspaper has run an article about the man who had a revelatory supernatural experience in the basement of the local funeral home.

Mr. Lightman employs a profoundly frustrating tactic in this section of the novel, and it is this: He doesn’t quite tell us what David saw. Near the end we get a description, but it’s just a couple vague sentences. I understand Mr. Lightman’s motives in focusing on the fallout of David’s experience rather than the experience itself — it allows him to concentrate on the ways in which people invest themselves in systems of belief for emotional reasons — but it denies the reader a crucial piece of information. If you don’t have a good idea of what it is that David believes he saw, how can you calibrate your assessment of his interpretation of it?

Mr. Lightman does manage a fine job of portraying the struggle between the rational and the irrational in David’s mind, however. David is at first presented as a man who believes that “logic is what holds it all together. Without logic … the entire world might come apart piece by piece, like when you pull a stray thread on the sleeve of your jacket.” Soon, though, Mr. Lightman reveals (in a quite lovely passage) that David has long felt he is “searching for something, although he doesn’t know what it is. At moments, once every few years, he has a brief sensation of almost grasping it … he feels something big, a flash of some totality, some grand sweeping thing like ripples moving out from a stone thrown in the lake.” It seems reasonable to suspect that despite David’s purported faith in logic, his dissatisfaction with the course of his life might predispose him to accept the idea of some “totality” beyond what is empirical, and Mr. Lightman dramatizes this psychological vulnerability with affecting subtlety.

“Ghost,” however, is a very short novel containing too many interludes with distraught families in the funeral home (one bereaved man, feeling guilty for having beaten his now-dead wife, asks David to pass his apology into the spirit world) and too much reminiscence about David’s ex-wife Bethany (who once covered her nude body with flour and asked for sex — which is actually kind of ghostly, wouldn’t you say?), so the book’s exploration of its central ideas feels a little cramped and truncated, and the story ends with an arbitrary tragedy that provides an easy sense of closure but feels non-sequiturial. Ultimately, Mr. Lightman seems to take a step back from the debate at the heart of his novel, throw up his hands, and simply acknowledge that humans are infinitesimal units in the hugeness of existence.

Mr. Antosca last wrote for these pages on Brock Clarke.