You might think that in writing a book with a protagonist who leads four parallel lives, chronicled over four decades, Paul Auster would have worked from some sort of master plan—if only to keep the details straight. Not so, he says. His 16th novel, 4321, will be published by Holt in January. “It’s so much more unconscious and organic: an idea just surges up, slowly, slowly, you start to think about it, but it’s all done in blindness and confusion,” Auster notes. “I don’t map out books in any kind of detail, and a lot of this book was pure improvisation. I would go downstairs to my desk in the morning, and I’d have a vague idea of what I wanted to do, but I felt I was plucking things out of the air in front of me and putting them on the page.”

The idea that surged up to launch 4321 was simultaneously simple and complicated: Archibald Isaac Ferguson, born on Mar. 3, 1947 (one month to the day after Auster), travels through childhood and youth with the same parents, the same extended family, and many of the same friends, but his journey takes four divergent roads, signposted by different circumstances. Ferguson-1 goes to Columbia University and becomes a journalist. Ferguson-2’s father builds a tennis center with the insurance money from a fire that destroyed the family-owned store; that same fire kills Ferguson-3’s father. Ferguson-4 goes to Princeton and becomes a novelist.

Auster says that he “doesn’t think there’s a human being alive who hasn’t speculated, what if? What if my father hadn’t been killed in that accident? What if I had hit a home run instead of striking out? It’s very easy to start playing out these alternate realities for yourself, and it’s a fascinating game to play.”

The what ifs in 4321 are matters of chance, a dominant force in all of Auster’s novels. His sense of the universe’s random nature came early, he says, on a summer day at camp when he saw another 14-year-old boy struck and killed by lightning. “This has haunted me my whole life. I’m convinced it changed my entire outlook about what it means to be a human being. Anything can happen at any moment to anybody: I think I never would have come to that conclusion if I hadn’t experienced that trauma. Fourteen is such a vulnerable age; you’re not a child anymore, but you’re certainly not an adult. You’re in flux, you’re becoming, so a big shock like that can have a deep impact.”

Another seminal moment came during Auster’s decadelong apprenticeship as a poet, essayist, and translator. “I had a very important conversation when I was living in Paris in the early 1970s,” he says. “I became close to a fascinating and original writer named Edmond Jabès, a Jew who was born in Egypt, who got kicked out in ’56 and moved to France. He was like my literary grandfather. One day we were walking along the street, and he said, ‘Every writer’s aim is to shake people up: to make people look at things differently and think about things differently, to subvert the conventions of art and ordinary thinking. If you are an avant-garde writer and want to splatter words all over the page and think that you are fighting a battle against convention, go ahead, but nobody is going to care. The only thing that is really subversive and powerful is clarity.’ This conversation has stayed with me, and it’s tremendously good advice.”

Auster followed that advice in the New York Trilogy, which established his literary reputation in the 1980s: City of Glass, Ghosts, and The Locked Room, which deal with such quintessentially modernist themes as the mutable nature of identity and the blurred boundaries between fact and fiction, but which do so with clarity, in the same lucid prose that weaves the multiple narrative threads of 4321 into a single coherent story.

The New York Trilogy and Auster’s equally well-regarded 1982 memoir, The Invention of Solitude, were released by small presses, and Auster worries that such essential outlets are at risk in the age of online bookselling. “Amazon is the enemy,” he says bluntly. “They’re out to destroy publishers and bookstores, and I don’t want to live in a world without publishers and bookstores.” At Holt, he relies on his editor Barbara Jones primarily for “moral support and friendship.” He adds, “Barbara is a very fine person, I admire and respect her, but I have in-house editing: Siri and I read each other’s manuscripts.”

Wife and fellow novelist Siri Hustvedt’s presence is almost palpable in Auster’s warm comments about her writing and appreciation of her support: “I admire Siri’s work enormously, I think she’s a genius, and she has always admired my work and been wholly behind it from day one—and we’ve been together more than 35 years. Here’s what we do when we read each other’s manuscripts: total honesty, because pats on the back are useless. If you believe in the other person’s project, you want it to be as good as possible. We all fall down at times, we all make blunders. Siri’s there to find the mistakes for me, and I’m there to do the same for her. She’ll say, ‘I don’t like that word; I don’t think that word is working,’ or, ‘That paragraph, no: you went too far,’ and she’s always right. I don’t think there’s a time when I haven’t taken her advice, and I think she’s always taken mine, too.”

Hustvedt is in Europe as we speak, and it’s not easy for Auster to be alone in their Park Slope brownstone two days after the presidential election. Like many New Yorkers, he’s still reeling from the results. “I feel as if someone I really care about has died,” he says. “My daughter [singer-songwriter Sophie Auster] called yesterday to say that people on the subway were utterly silent, everyone looking down, lost in some kind of grief.”

It’s as angry, polarized, and dangerous a time as the 1960s, when the writer and two of his Fergusons went to college, and Auster remains personally conflicted about the question he gives to one of them in 4321: “Ferguson-4 has the artist’s point of view about politics, which in my younger days was a tremendous torment to me: how can I reconcile the desire to be a poet with the necessity of being an active citizen and taking part in political life? I still haven’t really reconciled them, although I speak out and stand up when I feel compelled to. Ferguson-4 understands that he’s not going to fight on the barricades, that his job is to write his book. It’s hard to defend that, but I do believe, finally, that writing a novel is always striking a blow for democracy, because it’s the form that elevates the importance of the individual. We’re telling stories of lives—imaginary but vividly imagined, we hope—that allow the reader to participate in some kind of communication with another. That’s what it’s all about: I’ve said many times that a novel is the one place in the world where two strangers can meet on terms of absolute intimacy.”