A saga of a former student trying to learn about life, love, loss, and the nature of treason

The Israeli writer Amos Oz has said about his work that he is “normally” in “partial disagreement” with himself.

At times, his new novel, “Judas,’’ an erudite defense of the apostle whose name has become a synonym for traitor, a polemic about the fate of Israel, and a tender coming-of-age story seems weighed down with this idea.

Oz’s defense of Judas is a revisionist look at treason by a writer who has himself has been accused of it for articulating the very political positions various characters advance in his book — that there should be two states, that force cannot solve conflict in the region, that Jews, after centuries of feeling powerless, fell in love with force, that Israel has a right to exist but so does Palestine.

Whose book is this anyway?

But at other times, I felt that “Judas,’’ Oz’s first full-length novel since his 2004 best-selling memoir, “A Tale of Love and Darkness’’ (which last year became a movie directed by Natalie Portman), is as much a simple bildungsroman set in 1959 in Jerusalem, a generation after the founding of the state of Israel. Shmuel Ash, a gentle young man with asthma and an enlarged heart, is forced to drop out of school to get a job after his girlfriend dumps him, his work stalls out, and his father’s finances collapse.

Oz describes Ash with great compassion, as someone whose self-knowledge turns him inward. “But what do you do, he sometimes asked himself with disgust, beyond feeling pity?”

Ash becomes a caretaker for Gershom Wald, an elderly invalid living with his daughter-in-law, Atalia Abravanel, a striking and formidable widow (and a private investigator). He spends a few winter months in their attic “searching for something with no fixed measure.”

The residents of the house are haunted by their pasts. Atalia particularly is burdened by losses, secrets, and scars. Her young husband — Wald’s son — died fighting Arabs on a mountainside in 1948. Her father, Shealtiel, judged a traitor for calling himself a Zionist and for arguing for two states (one for Arabs, the other for Jews), was shot drinking coffee in his kitchen.

Ash, who was working on a thesis about Judas Iscariot before he left school, is drawn into the lives of the inhabitants of this gloomy house. He spends long house debating points of his thesis (among other things) with Wald: What would the fate of the Jews have been if Judas had not betrayed Jesus? What would it be like for the Jews if the original target of anti-Semites did not exist?

Ash’s thesis, studded with allusions to dense rabbinic tracts, boils down to his disregarding common wisdom about Judas betraying Jesus for 30 pieces of silver, arguing that Judas persuaded Jesus to go to Jerusalem because he had faith, because he believed in his miracles, because he thought Jesus would be able to leap off the cross.

Ash’s point — and Oz’s — is that Judas is sympathetic. After Jesus died on the cross, Judas was the only one to hang himself, as Ash writes, “from sorrow.”

A piece of Ash’s argument belongs to Oz, who believes that the inflexible always view those open to new ideas as traitors. But Oz makes his shy hero more than a mouthpiece in a novel of ideas. He is a character capable of change.

Part of that is his ability to love. While Ash is pondering the nature of betrayal, he has a brief affair with Atalia — in part out of curiosity. He is fascinated by her controversial father and tries to investigate what really happened to him.

One of the great pleasures of reading Oz is his unsentimental portrayal of love and family. Here, as in much of his other writing, love cannot solve problems, although it can make life tolerable for a while. Ditto for family, which can only go part way to explaining and easing the sins of the past.

This makes sense, since history looms over the characters like a gray winter sky. To read “Judas’’ is to be reminded of how impossible a task the Zionists set for themselves when they founded the state of Israel. As Ash puts it, the task is no less than “how to turn a hater into a lover, a fanatic into a moderate, an avenger into a friend.”

But Oz is not content to just leave his book with a political message about the irreconcilability of the Palestinians and the Israelis. One of the most striking sections of “Judas’’ is toward the end after Atalia gently ends their affair and tells Ash that the time has come for him to move on with his life.

Here, Oz gives the reader one chapter from the point of view of Judas. Although it is not clear whether this is supposed to be a look inside Ash’s mind or Oz hurling us backwards through time and space, it enriches the story to read about Judas’s uncertainty, suffering, and shame.

“[W]e are all at the mercy of forces that make us do what they want,” Atalia tells the young man. It is one of the wisest sentences in this wise, brooding, and sometimes contrarian book. JUDAS

By Amos Oz

Translated from

the Hebrew by

Nicholas de Lange

Houghton Mifflin

Harcourt,

305 pp., $25.

Rachel Shtier is the author of three books, most recently, “The Steal: A Cultural History of Shoplifting.’’