There they go again. The feminists are at it once more, tearing one another to pieces over work vs. home, just the way they did at the birth of the modern movement 50 years ago.

This time, it’s Sheryl Sandberg’s new book that has set them off. In “Lean In,” Sandberg, Facebook’s chief operating officer, encourages women to work hard, go after leadership positions, have a husband and children and a 50/50 compromise relationship with their spouses — all of which she has.

The reaction has been, well, explosive. Just as it was when Gloria Steinem — quoting educator Irina Dunn — declared that “a woman needs a man like a fish needs a bicycle.”

As I look back on what has happened in the past 50 years of the women’s movement, I am struck by how the more things change, the more they stay the same. Women have made enormous strides, largely due to the women who started these movements then. Much has changed in the workplace, and women are breaking barriers every day — though Sandberg argues they should be even further along. Where things still are murky is in the private lives of women. How do you manage having a career, having a marriage or a relationship and having children? That balancing act is still uppermost in the minds of most young and middle-aged women today, much more so than for their husbands or partners. Today, as then, the way you answer the question can pit you against other feminists.

At one point I found myself in the middle of this fight. When “The Feminine Mystique” was reissued in 1997, Betty Friedan wrote in the introduction: “in all the arguments about men not doing enough of the housework and child care, I’ve heard women recently admit that they don’t like it when men take over so much of it that the kid comes to Daddy first with her report card or cut finger. ‘I wouldn’t consider letting Ben take him to the doctor,’ my friend Sally said. ‘That’s my thing.’ ”

I’m that Sally. And that was and is my thing. Who would have predicted that?

I was a senior at Smith College when Friedan’s book came out. It changed my life. The mantra in our class was, “A ring by spring.” That was if you hadn’t already dropped out of school to get married.

The pressure to get married was huge. I didn’t dare tell people I didn’t want to. When Friedan’s book came out, it articulated all the doubts I had about becoming a housewife. My mother had wanted a career but married an Army officer and moved every year and a half, making it impossible for her to work. She was completely dependent on my father. “Always have some work you love and your own money” was the one thing she kept telling me.

Friedan, who became a close friend, started a discussion — some might call it a revolution — that has never ended. It ebbs and flows from year to year, occasionally erupting into a national debate, but the issue — what is and should be women’s role in society — never goes away.

Gloria Steinem, who was a friend as well, picked up the mantle from Friedan and started the Women’s Liberation Movement and Ms. Magazine. But her message was more strident — that fish-bicycle thing.

Friedan and Steinem both went to Smith College. Although Friedan identified “The Problem That Has No Name” — which was that the well-educated, middle-class woman had nothing outside of the home to fulfill her — she was totally in favor of marriage and children. She loved men. She felt that what was missing in women’s lives was meaning. When women had something that gave their lives meaning outside of the home, everybody was happy.

Steinem was beautiful and glamorous and became a role model for women who didn’t want to be associated with what most people thought of as feminists — unkempt, hairy, bra-burning, man-hating women.

Steinem made it clear she wasn’t interested in marriage and children. Many young women who looked up to her thought they weren’t true feminists if they wanted or needed a husband and a family. A female colleague in her late 30s approached me during those early days. She was close to tears. After begging me not to tell anyone, she confessed she was pregnant. “I’m so sorry,” she said. “I didn’t want to let the side down.”

Some women gave up chances to marry and have children; others, already married, had their marriages torn apart. Women became divided between those who wanted to work but didn’t want to relinquish their roles as wives and mothers, and others who devalued the domestic part of the equation.

In 1977, an International Women’s Year conference in Houston exposed all the conflict engulfing the women’s movement. I covered it for The Washington Post. Here’s how I described it: “Ambivalence, uncertainty, conflicting emotions. Everyone who was in Houston . . . felt them. Joy. Exhilaration. Disgust. Embarrassment. Sentimentality. Confusion. Shame. Anger. Affection. Uneasiness. Amusement. Frustration. Pride. At once one was proud to be a woman. And ashamed. One wanted to be there and didn’t. At every turn there was something that inspired pride and something that embarrassed.”

Friedan and Steinem had a clash over strategy that upset a lot of people. Steinem spent her time trying to create compromise so it wouldn’t look like a catfight. But the fact was that the two were on a collision course.

I wrote about the convention in as objective a way as I could, concluding that not much had been accomplished. Steinem was not happy with my piece. “You have to decide whether you’re a feminist first or a journalist first,” she said.

Years passed, and women settled into a more comfortable place, making their own choices both at work and at home. As they aged, many of the diehard feminist were proving to be more traditional than they had presented themselves before, and I wrote a piece about this. I suggested that some of these women had encouraged others to give up marriage, relationships and children while seeking those very things themselves.

I quoted Steinem, who had written a book in which she admitted falling in love with someone who treated her badly. I wrote: “She had seduced him, she says, by playing down the person she was and playing up the person he wanted her to be. When he did fall in love with her, ‘I had to keep on not being myself.’ ”

I ended by saying that we need leaders like Betty Friedan who could speak to the real needs of women.

Steinem was not happy. She was quoted in the New York Observer as saying that “Sally Quinn is a waterbug on the surface of life.”

Steinem later married in her 60s and had a wonderful relationship until her husband sadly died some years later.

She was responsible for huge changes for the better for women all over the world, as was Friedan. Their messages and their methods of operations were different, that’s all.

Sandberg’s “Lean In” has a lot of good advice for women who aspire to the executive suite and the men already there. She has been unfairly criticized for writing for the elite and ignoring the poor working woman who has no choices. But that’s not the book she wanted to write, and she addresses that over and over in her book.

But when the book gets into home life and child care, her advice is not so easy to follow. She is a superwoman, worth hundreds of millions of dollars and by all accounts terrific at her job. She has two children and a husband who shares 50 percent of the housework and child care. She sometimes works 12 hours a day and travels extensively and has plenty of help, though she will admit that she often feels guilty about her children.

When I read the book, I found myself feeling agitated. I couldn’t sleep. Finally I realized that the book had made me feel inadequate, as though I hadn’t worked hard enough and hadn’t accomplished enough. But I finally realized that I have had exactly the life I wanted and still do. I did what felt right for me. I had a child who was terribly sick for 16 years, and that made a difference, of course, but I’m not sure I would have done anything differently had I had a healthy one. I cherish all of the time I spent with my son. Being a mother has been and still is the most important thing I have ever done.

Am I a feminist? Of course. How can you not be if you believe in equality for everyone? Sandberg is a feminist. So is Steinem, so was Friedan. I am proud of what women have accomplished. There are so many role models now. It could be Michelle Obama, a Princeton and Harvard Law graduate who gave up her career to raise her two children and support her husband in his political career. Or it could be Sheryl Sandberg.

I don’t think we need another women’s movement now. Those days are over. Women should live our own lives the way we want to and respect those who live their lives differently. Women will be better off and so will men.