Why have a baby? For a woman in her 20s or 30s who’s accustomed to living independently, who feels no religious or familial obligation to bear children, the answer comes down to the vagaries of desire: Do you want it, does the other person, how badly?

The simpler question might be Why not have a baby? Here, the obvious practical issues — money, time — are easier to weigh. How to pay for the baby, who will watch the baby, where to put the baby, will the baby get in the way of everything else? And this assumes a partner on hand; without one, challenges multiply. There’s also the prospect of impending climate apocalypse, which at least one woman I know has cited as reason enough not to procreate.

Practical matters, however, do not concern the writer Sheila Heti, who takes up the problem of whether to have a baby in her engrossing new autobiographical novel, Motherhood. “I lived only in the greyish, insensate world of my mind,” she writes, and in this setting, the question is something more like this: What does it mean to have a baby? From there, a cascade — does a baby make you happy, what kind of woman has a baby, what kind of woman doesn’t have a baby, how does a baby change you, is having a baby selfish or is it selfless, is not having a baby a way to avoid real work, real meaning, real life … or is that what having a baby does?

Motherhood dwells within this uncertainty to an extent that will exasperate some readers as surely as it will animate others. I am only one reader, and yet I’ve found myself in both camps: I read it the first time and felt profoundly, irresistibly annoyed; I wanted to keep thinking about it enough that I wanted to read it again. The second time I felt startled and embarrassed by the things I’d missed the first. In the months that followed, I began waving it under friends’ noses like smelling salts, eager to observe the reactions it provoked. Moms of small children loved it, and moms of small children rolled their eyes. People who couldn’t get through Heti’s last novel devoured this one. A friend in her late 30s, navigating the same straits Heti describes, didn’t want to go anywhere near it. Then she did, and said how glad she was to have changed her mind. She’d been feeling so alone in her uncertainty — Motherhood was “the friend that I wanted to talk to.”

In April, I met Heti at the Lakeview Restaurant in Toronto; I had a beer and she ordered a double Scotch. The Lakeview is a 24-hour diner Heti chose for its enclosed, quiet booths. They turned out not to be quite as enclosed as she’d remembered but still provided a suggestion of privacy — womblike, that is, but not too womblike. Bruce Springsteen was playing.

Heti is a Canadian writer who first attracted widespread attention in the United States with her 2012 novel How Should a Person Be? The book incorporated real emails and tape-recorded conversations as well as first-person narration from a character named Sheila, a writer, focusing on her friendship with a painter named Margaux. The book was polarizing — in The New Yorker, James Wood called it “hideously narcissistic” — but also found prominent admirers. In March, when the New York Times anointed a “new vanguard” of 15 female writers “steering literature in new directions,” it included Heti. In the accompanying note about How Should a Person Be?, critic Dwight Garner praised her ability to write prose “that feels like actual, flickering, unmediated, sometimes humiliating thought.”

Women in Clothes, the 2014 book Heti edited with Heidi Julavits and Leanne Shapton, drew together hundreds of women’s responses to a survey about what they wear and why, compiling an encyclopedia of female self-presentation. It also gave Heti’s interest in intimate observation an outlet more accessible than her novels and went on to become a best seller.

“One good thing about being a woman is we haven’t too many examples yet of what a genius looks like,” Heti wrote in How Should a Person Be? This was sort of a joke, as she had to explain to a credulous interviewer at the time: “The next line is, ‘It could be me.’ ” But one good thing about this view of female genius is the way it proposes seeing gender: not as a basis for oppression but as a source of possibility.

Motherhood joins How Should a Person Be? and Women in Clothes to form what might be read as a field guide to womanhood in a particular literary-bohemian milieu. Heti started the book after entering her 30s, when her uncertainty about motherhood had begun to feel like limbo. She remembers a conversation in this period with the writer Sarah Manguso, who became a mother in the course of their friendship and whose 2015 memoir, Ongoingness, deals with the early days of parenthood. Manguso told her that actually having a baby felt like a relief after the long time of wondering whether she’d have a baby. “I remember thinking consciously, Oh, I need to stay here longer,” Heti told me. “This is a place to write about.”

When I spilled beer on my phone during my lunch with Heti, she worried about whether it was one of the waterproof ones (hers is not) and wiped up my mess with a napkin. In the course of our time together, she also worried that I might be hungry after traveling (she recommended the poutine), advised me on the best time to call a cab (earlier than I thought), and urged me to use my umbrella, since I lacked a hat in the rain. That evening, in the bathroom of the suburban public library where she was giving a lecture, she offered me a Clif Bar from her purse. I accepted.

“I’m surprised that I’ve written three books about or for mainly women,” Heti said over the poutine. Gender can be a source of possibility, but it can also be limiting when it becomes the only lens through which people see your work. While certain readers applauded How Should a Person Be? for championing “female friendship,” this was not something Heti especially set out to do. One of her inspirations for the book was My Dinner With Andre, but all anyone ever wanted to ask her about was Girls. “Two friends talking for a long time about art?” she said of the 1981 Louis Malle classic. “Like, why did that not once come up?”

The Lakeview Restaurant is a ten-minute walk from Heti’s apartment, where she lives with her boyfriend and her Rottweiler, Feldman (puppyish, but with a name that makes him sound “like an old Jewish man”). Two big brown rabbits, Bun and Bun-Bun, occupy the front yard. Heti has lived in Toronto her whole life, save for two short stints in Montreal, and in her writing, the city often sounds like a place where government health care has fostered the fantasy version of college life: where friends all live cheaply nearby and run into each other, drink, go on long walks, have long talks, and undertake projects. At 41, Heti herself — fair and faintly elfin, with overgrown bangs — could pass for a grad student. The community she describes combines artistic seriousness with a playful sense of humor and a constant appetite for conversation, argument, and collaboration.

“I think that part of the reason I like collaboration so much is because it’s something unexpected coming in, and you have to stretch yourself to absorb it,” she told me. In writing the new book, she wanted to be more alone than she’d been when she was working on How Should a Person Be? and tape-recording her friends. “But I didn’t want to be that alone. I didn’t want to be so alone that there was no surprise, you know?” Motherhood’s unnamed narrator begins by asking questions while she flips three coins — two or three heads, yes; two or three tails, no — in a modified version of the I Ching. “Is this book a good idea?” she begins. “Yes,” say the coins, daring the reader to disagree.

Her character’s encounters with a tarot reader and a psychic are a similar intrusion of the unexpected, though Heti also hopes they provide a sense of desperation. “You don’t go to tarot readers or psychics when everything’s going well,” she said. “It’s always evidence of rock-bottom.”

I feel like a draft dodger from the army in which so many of my friends are serving.

At first, Motherhood was supposed to look something like Women in Clothes. Heti imagined a collection of interviews with women about having children, or not. (There was also a time, once she’d reimagined the book as a novel, when she thought it might incorporate the comments on Daily Mail articles about mothers; she read them obsessively.) In the book’s final form — fragmentary, cyclical, a collection of scraps and dreams — conversations still echo throughout. The narrator talks about motherhood with other women inexhaustibly: younger women, older women, women her age, women with babies, women with frozen eggs, women with regrets. Miles, the narrator’s boyfriend, seems surprisingly peripheral to all this. He has a daughter from a previous relationship and tells her he’ll have a child with her if she wants — but it’s her decision and she has to be sure. Motherhood, in this book, exists most of all as a force that shapes women’s lives and their relationships with one another.

Heti approaches the subject with an observer’s curiosity more than a deliberate agenda. Growing up, she remembers feeling distant from the received version of femininity: The word mother, for example, seemed to refer to a way of being female “that just I never identified with.”

One of the women the narrator speaks with in the novel, an American writer, tells her that whenever she meets women their age, the first thing she wants to know is whether they have children, and if not, whether they plan to — “It’s like a civil war: Which side are you on?” Yet this sense of the trenches transcends “mommy wars” cliché. The experience of childbirth and new motherhood — even just the question of motherhood — comes to look like a female proving ground; something like what war has been to male writers. (Reviews have compared Rachel Cusk’s motherhood memoir A Life’s Work to “a war diary” and Elisa Albert’s motherhood novel After Birth to The Red Badge of Courage.) Life-or-not-life stakes loom. “Like soldiers nudging each other into battle, we nudge each other into relationships,” the narrator reflects at one point. “Stay there, we say. Don’t run from the front lines.” The encounter with human life in extremis gives rise to a kind of camaraderie, but it’s a dark one, and she’s contemplating it from the outside. “I feel like a draft dodger from the army in which so many of my friends are serving,” says the narrator, “just lolling about in the country they are making, cowering at home, a coward.”

Foremost among the women the narrator contemplates is her mother, a Hungarian immigrant and a doctor who, in her daughter’s memory, is always working and always crying. As in Heti’s own life, the narrator’s father handled the bulk of child rearing. Growing up with this particular mother has left her uncertain whether children can ever be a pleasure rather than a source of pain. The inherited focus on work (“My mother works hard, and I work hard, too,” she writes) means that a particular concern is how having a child might affect her life as a writer. She goes to dinner with a pregnant friend who’s anxious that the narrator is progressing in her work while she falls behind in her own: “Stop making things!” this friend says in a panic. But, on the other hand, the narrator wonders, “Could I ever hope to be a good enough writer — capture on the page what being human felt like — if I had not experienced motherhood?”

In the meantime, as she scrutinizes the tea leaves of her mood, she finds herself increasingly isolated. “I had always thought my friends and I were moving into the same land together, a childless land where we would just do a million things together forever,” she thinks. Instead, “one by one, the ice floe on which we were all standing was broken and made smaller, leaving me alone on just the tiniest piece of ice, which I had thought would remain vast … It never occurred to me that I’d be the only one left here.”

If the novel has a climax, it arrives when the Sheila stand-in shows her manuscript about motherhood to her mother and gets to hear her response. This fulfills the narrator’s emerging sense that “motherhood,” for her, might be bound up more in her relationship to her mother and grandmother than in producing some future child.

I found myself curious what my own mother might make of the book — as a woman who wasn’t sure she’d be a mom but then was, as a woman currently campaigning for grandchildren. I sent her a PDF to read on her iPad. She called me after she’d finished.

“You’re not going to like this,” my mom warned me when I asked what she thought. “But why didn’t she go on the drugs sooner?”

Ah, yes: the drugs. Midway through the book, the narrator begins to recognize a connection between her moods and her menstrual cycle. There’s a pattern, it turns out, to the violent internal weather systems she’s endured, and online she finds a community of women whose experiences mirror her own. In some cases, these women take antidepressants to alleviate their symptoms. She gets a prescription herself. Everything changes. “How was it possible that antidepressants were legal?” she wonders, experiencing free-floating joy on her walk home from the grocery store. “Did half the country walk around feeling this way — sparkling with ease and light?”

This happens near the book’s end, and while the remaining 40 pages aren’t necessarily nonstop sparkle, things do get a lot easier. Previous moments — “Outrun your tears like an athlete every day,” she once told herself — appear in a new light. Were they signs of existential struggle or were they symptoms?

My mother’s personal approach to motherhood dictates treating symptoms whenever possible. But, in answer to her question, the delay — on the part of the character or the author — seems understandable. If you are accustomed to using your own thoughts and emotions to make sense of the world (if, for example, you are a novelist whose work mines autobiography), what could be more unnerving than the suggestion that your thoughts and emotions can’t be trusted — that you might be an unreliable narrator of your own life? This, perhaps more than any coin toss or collaborative partnership, is cause to wrestle with the unexpected. Near the end of Motherhood, the narrator wonders what it means for a story to hinge on chemical intervention: “I don’t know what kind of story it is.”

From one angle, Heti’s resistance to clear answers can look like a cop-out; from another, like a novelist taking full advantage of her medium — of fiction’s right to be slippery. (The fact that Heti’s fiction draws so directly on her life can make this possibility easy to miss.) Or maybe Motherhood foils my abilities as a critic: I like the book as a catalyst for thought, and admire its ability to withstand sustained consideration.

Heti hesitated to include the drugs in the book. “I kept putting it in and taking it out,” she said. She did not want to end the book with a pharmaceutical deus ex machina, in which “antidepressants fly in like Superman.” The critic Dave Hickey, a friend, convinced her she should: “You gotta put them in, because it’s true,” she remembers him saying. “Oh, okay,” she thought. “That makes it really simple.” She’d fixated anxiously on the question of motherhood, but relinquishing her relentless anxiety did not make the question less real. “It sort of lets the end of the book happen,” Heti said.

Throughout Motherhood, in her wariness of motherhood, the narrator is on guard: against the possibility that a baby could change her, or that her body could have an agenda at odds with her own. Acquiescing to the mysteries of hormones and brain chemistry doesn’t persuade her to have a baby, but she does find herself accepting the inevitable helplessness of life with a body — of being something besides a grayish, insensate mind. A baby changes everything, but so do SSRIs, and so does the passage of time.

“When I was writing the end of the book, it felt very clear to me that the question was solved,” Heti said — in the book, she does not have a baby. “And then as soon as the book was done, I was back in the nonfictional world.” In the nonfictional world, the question remained. She started the book when she was 33; now she was 41. She had lived seven more years without a baby, and her life was fine: She was happy. “When I was younger, I think that I felt like I could only live one way, and I had to figure out which of those one ways it was going to be,” she said. She now felt she could live either way and be fine. “I have no anxiety about making the wrong decision.”

“There’s also something about every year getting closer to death,” she said and laughed. “It’s not like I have to live through eternity with whatever decision I make. It’s only another 30 years … It’s just until you die, and that’s not that far away. It’s a bit of a lighter feeling, somehow.”

Motherhood is out today by Henry Holt.

*This article appears in the April 30, 2018, issue of New York Magazine. Subscribe Now!