(Henry Holt)

Sebastian Faulks, best known for his romantic wartime novels “Birdsong” and “Charlotte Gray,” once again calls upon the horrors of war and doomed love in “Where My Heart Used to Beat,” his 13th novel.

The dramatic effect of both is, however, swamped by relentless theorizing, chiefly on the part of the book’s cheerless narrator, Robert Hendricks. He is in his early 60s when we meet him. It is the 1980s and, ever since a passionate wartime affair ended some 40 years ago, he has not been able to feel love for anyone except his dog, Max. He is, as he puts it himself, “an habitué of loneliness.” He is also a psychiatric doctor who believes that neuroscience and evolution are the key both to his mental condition and to what separates human beings from the rest of creation.

The book sets off on its scattered way with Hendricks disgracing himself by inviting a prostitute to an apartment borrowed from an absent friend. Then he gets a letter from an old man he’s never heard of, a Dr. Pereira, another psychiatrist, who asks him to visit him on his “lovely island off the south of France.” Pereira says he can show him some photos of Hendricks’s father, who was killed during World War I. He also wonders whether Hendricks would consider becoming his literary executor. After some hesitation, Hendricks decides to go. On the island, he delves into his memories — of his childhood, his wartime experiences — and of his lost love.

Unfortunately, Hendricks can be a terrific bore, waxing rhapsodic about neuroscience and his theories about humanity. “Homo sapiens is a freak,” he claims, in that it suffers “the curse of self-awareness,” which itself is “the result of catastrophe in natural selection.” He says that the “thing that makes us different is” a neural tic, “a freak ability to connect at will a moment of physical awareness to the site of episodic memory. That is the miracle of our conscious humanity. A mutation that gave rise to an illusion.” In Hendricks’s mind — or, sequence of firing synapses — “this unique, human-defining sense of having a self turns out to be a fiction anyway.” In fact, “the illusions, delusions, the abstractions of art and lunacy . . . all spring from a few cells that were rearranged by a mistake but remain physical cells. With mass.”

(Muir Vidler)

It’s impossible to say whether readers are supposed to find all of this quasi-nihilistic, radical materialism convincing, or at least interesting, or whether they are meant to feel sorry for poor old Hendricks with his attempts to persuade himself that his feelings for his lost love “were no more than the side effects of neurotransmitters that had serially misfired.” I would guess both.

Still, and not a page too soon, these neuro-scientific formulations are pushed to the side as Hendricks describes his experiences as a commissioned officer: first, in the British Expeditionary Force’s landing on the continent and subsequent evacuation from Dunkirk; then, after a spell guarding England’s coastline, in North Africa; and, later, most terribly, at Anzio in Italy — one of those fatally bungled battles that Faulks has always evoked with such brilliance.

It’s all here again: the botched planning, lack of coordination and cooperation among various forces, the ruthless deployment of men and their powerlessness against their superior commanders’ coldbloodedness, miscalculation, negligence and outright stupidity. Faulks’s writing leaps into color as he describes the scenes of battle and the wretchedness of the soldiers. Mired in a fetid soup of excrement and deliquescent corpses, they “had become semi-aquatic mammals, a kind of large and vicious water rat, living in and above the drainage ditches of the marsh.”

Alas, the only sections with any vigor or narrative substance are those concerning Hendricks’s war and his one true, though broken, romance. The rest of the novel is an unmeshed assemblage of case histories, accounts of Hendricks’s psychiatric practice, expositions of his theories: his own and those of Dr. Pereira. There are also miscellaneous excursions into Hendricks’s past, and a lot of trips — to Dr. Pereira’s island, to the country to see an old officer, to Switzerland on another mission, and, most pointless and tedious of all, a sojourn in a coyly unnamed European city during which he wrote a book. (“The book went on at a steady three pages a day.”) Finally, at novel’s end, a secret is revealed, to us and to him. It is arresting enough and provides yet another glimpse of the madness of war, but it has no refracting or amalgamating effect on the collection of episodes that make up the first 300-plus pages.

“Throughout my life,” Hendricks tells us at one point, “I had thought that if I could get through this section of it, then the pattern of a destiny would reveal itself.” In this, at least, he is not alone. Through section after section, the reader has been looking for something similar, or at least for a story.

Katherine A. Powers is the editor of “Suitable Accommodations: The Letters of J. F. Powers, 1942–1963.”

Where My heart used to be

By Sebastian Faulks

Henry Holt. 333 pp. $27