It spoils nothing to disclose that Peter Debauer — a Swiss-German child of World War II, a skilled masseur, a brilliant liar, and the modern-day Telemachus at the center of Bernhard Schlink’s vexing “Homecoming” (Pantheon, 260 pages, $24) — never completes his doctoral dissertation. But as is the case with many who turn to academic work to explore man’s true irrationality, the question that haunts Debauer’s life is expressed in this doomed project. “I intended to demonstrate that justice is of use only insofar as its claims are formulated and put into practice without concern for social utility. Fiat justitia, pereat mundus: Justice be done though the world perish.”

Like his creation Debauer, Mr. Schlink, too, was born into a world that had narrowly avoided perishing under the weight of too many utopian visions. Mr. Schlink was trained as a legal scholar — he still teaches law in Germany and occasionally in New York — but he began publishing detective fiction in the mid-1980s. In 1995 his novel, “The Reader,” was greeted with great international acclaim, both for its learned meditations on memory and justice and its quiet, hauntingly erotic style. His books calmly describe the burden of his generation, the first to grow up postwar, encoded with guilt, and make amends with their awful inheritances: the legacy of Hitler’s crusade and the knowledge that their parents had been powerless to prevent it.

This burden matters little to Debauer; as a young boy, history is incidental to him. He is proud to be half Swiss, but only because the Swiss trains boast cleaner, smarter designs. He acquires a passion for fables of justice from his grandfather, yet he doesn’t recognize his grandfather’s own troubled relationship to the unmoored world that took the life of Peter’s father. When Debauer abandons his studies, it is because his “thoughts refused to coalesce into a system.” He could just as well have been describing our relationship with the past, digestible in episodes and anecdotes, but defiant to the structures of reason we continue to impose upon it.

There is something about the older Debauer that seems profoundly off-balance. As he matures, he becomes increasingly detached from those around him, “watching history from a distance,” traveling to America and studying massage, and bounding from one passionless relationship to another. As the Berlin Wall falls, he ponders the everyday acts — the cooking and cleaning, family get-togethers, etc. — nestled within this grand gesture of history. Debauer’s is a life lived within great historical change, but not of it. Only one thing entrances Debauer for more than minutes at a time: fragments of a story he read as a young student, on discarded manuscript sheets his grandfather (who was an editor) had given him for use as scratch paper. The scattered pages describe a young German soldier who escapes from a Russian prison camp and embarks on a fantastic journey homeward to his wife. When he finally reaches his old apartment, he excitedly climbs the stairs and comes upon his wife in the doorway — only to find her ashen with shock. She holds a little girl in her arms. Another peeks through the window of her apron, and a man stands beside her with his arm around her. This is the book’s penultimate page; try as he does, Debauer cannot find a copy of the book anywhere.

Debauer becomes obsessed with discovering what happens next, and the mystery spreads outward: Who is the author of this story? How did it end up in the possession of his grandfather, and why did his grandfather implore Debauer never to read the stories on the other side of his scratch pads? And what of Debauer’s father, who his mother and paternal grandparents refuses to discuss?

Discovering something resembling purpose, Debauer orients his life around this singular pursuit of personal discovery, and here Mr. Schlink’s nesting doll of a novel truly begins to dazzle. Vague inquiries into the nature of the individual and society come to life as settings; idle choices unfold into worlds of moral crisis, and every rereading of the German soldier’s odyssey yields a tiny new clue. Soon, Debauer finds himself at the top of the stairs, ready to knock on a strange door. But what can he possibly hope to find? Debauer’s stubborn pursuit of his family’s secrets nearly consumes him, recalling a half-noble, half-cautionary belief held by his grandfather: “There are times when doing something crazy is right, provided you do it all the way.”

It is this edge of reason — the possibility that morality is tentative and provisional, rather than iron-bound — that fascinates Mr. Schlink, and it draws him toward the ideas of Hannah Arendt, Stanley Milgram, and Paul de Man, all of whom are briefly invoked in “Homecoming.” His propensity for citing these figures by name or inserting lengthy passages of literary or legal criticism is generally refreshing. But his erudition plagues the book’s final episode, too loud an echo of actual history, and a rare moment of lapsed subtlety. Just as with the tale of the wayward German soldier, it is Debauer’s personal odyssey that mesmerizes.

Much like “The Reader,” “Homecoming” is an exceedingly delicate meditation on the German past that refuses to moralize. Decent people can be driven to do the devil’s work, just as truly moral verdicts can result in unimaginable collateral damage: Debauer witnesses both of these. But there is a smaller, personal justice that underpins “Homecoming.” No character’s past features obscure tales of concentration camps, blind, anti-Semitic hatred, or anything else truly atrocious. Their acts of cruelty were staged far from the grammar of nation and duty, order and justice, in the margins of history.

Mr. Hsu teaches English at Vassar College. He last wrote for these pages on G.V. Desani.