Gayle Tzemach Lemmon

The Facebook COO’s new book Lean In encourages mothers with careers to opt out of the parent-or-careerwoman binary and firmly choose both.

At a wedding this summer, while I was eight months pregnant with twins, an older gentleman sitting next to me asked me whether I still worked in finance.

No, I told him, at the moment I was focused on my next book project, think-tank work, and several magazine pieces.

“Well,” he said with a gentle, nearly sympathetic, smile, “in any case, soon you will be pushing three babies in a stroller, right? Won’t leave time for much else.”

Annoyance swelled up into my already enormous stomach. When our table rose to watch the bride cut the cake I scurried two seats over to my husband and fumed. “I was so irritated I couldn’t even come up with a clever answer, other than to say that the kids have a father, too,” I said. “No one would ever say something like that to you.”

My husband laughed and told me not to pay any attention. “It’s just because people think that women can only be one thing.”

And therein lies the rub.

Somehow, today—even while women learn and earn in greater numbers than ever before—the idea that women live in an “either/or” world stubbornly hangs on. A woman can either be a mother or a professional. Career-driven or family-oriented. A great wife or a great worker. Not both. In other words, the choices are Donna Reed and Murphy Brown (pre-baby). Precious few Clair Huxtables out there.

That is the challenge Sheryl Sandberg’s book sets out to tackle. In a women-in-the-workplace discussion consisting mostly of “either/ors,” her argument in the upcoming book Lean In injects the word “and” into the conversation in a way that urges women to bring their “whole selves” to work. Choice is good, and so is aspiration. Ambition is great, and so is telling your boss that you want to have children. Working hard at your job is important, and so is finding a way to leave the office early enough to be home for dinner with your kids.

Already, weeks before the book’s publication, criticism is within easy earshot. A 20-something friend told me that several women she respected greatly argued that Sandberg is hardly representative of others and that her advice is impractical for the non-wealthy. But it seems to me that this criticism misses the point. What Sandberg offers is a view that shows 20-somethings like my friend that choices and tradeoffs surely exist, but that the “old normal” of blunting ambition so that you can fit in one category or another does not have to be the way it is. And that each of us has a say in what comes next. And that includes men.

We live in an era of immense change when it comes to what women do, how they do it, and with whom. 2011 marked the first year in which more women than men had advanced degrees. Between 1970 and 2009 the number of jobs held by women leapt from 37 percent to close to 48 percent. The boost in productivity resulting from women’s increased labor participation accounts for 25 percent of U.S. GDP. Women own nearly 8 million businesses, enterprises that provide more than 20 million jobs. And as researcher Liza Mundy noted in her recent book, nearly 40 percent of wives in the U.S. now earn more than their husbands; Mundy predicts in a generation breadwinning wives will be the majority. Yet no real evolution in our expectations for women’s lives and women’s ambitions has accompanied these numbers, as Anne-Marie Slaughter’s zeitgeist-channeling 2012 Atlantic story “Why Women Still Can’t Have It All” points out.

Sandberg’s proposition, though, looks a lot more like most women’s lives than the “either/or” model into which women’s lives get shoved. Many women navigate the “ands” every day, juggling a work life and a family life whose demands have meshed into one another in our constantly connected, 24/7-everything world. They don’t have the luxury of choosing one or the other because they are too busy doing both. And as I have argued here at The Atlantic, all of these are undoubtedly high-class conversations the women I grew up with never had the chance to have.

Still, it is relevant to all women that, as Sandberg notes, “the blunt truth is that men still run the world.” Women are fewer than 5 percent of all Fortune 500 CEOs and hold less than 20 percent of all executive board seats. Half the population accounts for barely 10 percent of all heads of state. And it was enormous progress for women to reach the 20-percent mark in the U.S. Senate last year. These dismal numbers and the lack of power they indicate are why it matters that the land of “and” is not only where women live now, but where they should want to stay and prosper. When 50 percent of the country has a kiddie seat at the head table, making room for others gets a whole lot harder. (Sandberg argues that women should, quite literally, sit “at the table” of power in which decisions get made.) Creating a world in which the next generation of talent gets to exercise its potential instead of bumping its head against career-stifling stereotypes or soul-crushing ceilings is in everyone’s interest—and the American economy’s.

Still, though, even when you succeed in winning fame and fortune in the world of “and”, sometimes others make it “either/or” for you.

In a recent Rolling Stone piece on the end of the long-running television program 30 Rock, show creator Tina Fey said the show had run its course, and dropping ratings meant no more. She wanted to do some movies and develop a multi-camera TV show while staying close to home and her two small children.

Her fellow 30 Rock actor Alec Baldwin had a different and somewhat more detailed explanation.

Baldwin, the magazine wrote, is “convinced that having a second child, in 2011, may have been the breaking point for Fey. ‘I saw a real difference in her,’ says Baldwin. ‘Tina always had her antenna up, but this year was the first time where she came in and laid down on the couch on set, and you could tell, she’s a mom. She’s fucking wiped out.'”