The following is an excerpt from Gloria Feldt’s new book No Excuses: 9 Ways Women Can Change How We Think About Power.

Why a Woman Must Secure £500 and a Womb of Your Own

 “I don’t want to, you know, say to Joe, ‘Hey Joe, can I have a hundred bucks for this?’ . . . I think it’s important for every woman to have her own money and be independent.”

—Jill Biden, wife of Vice President Joe Biden and the first woman in that role to continue her professional employment

“No woman can call herself free unless she can own and control her own body. No woman can call herself free unless she can decide for herself whether and when she will become a mother.”

—Margaret Sanger, founder of the American Birth Control Movement

Money. Sex. Power. These are the stuff of soap operas to be sure, but that’s only because they are the sinew and soul of human existence. And women’s relationships with all three are shifting so rapidly today that men and women alike may feel a sense of chaos as a result. No excuses for that. A cultural shift to incorporate women’s full equality, after all, affects everyone, and reproductive choice is fundamental to equality.

Money and sex have always been linked. They are symbolic but tangible representations of the two essential precursors to power of any sort: the human right to own and control one’s own body and the economic right to earn one’s way to independence. And the two, though separate and not always perfectly in tandem, are intensely connected. When we have these two basic capabilities—economic and reproductive self-determination—we have within our reach the greatest power of all, the one that makes us human and enables us to flourish as human beings: the power of choice, nothing less than the power to chart the course of our own lives.

Economic and reproductive self-determination work together. I think of them like those executive toys, Newton’s Cradle, where the movement of one metal ball suspended on a rack with four others creates a kinetic energy that impacts the ball on the other end of the line, even though what makes this so isn’t necessarily obvious. The laws of physics are sometimes inscrutable, but they are always there, transmitting the motion even when it’s unseen.

My own experience as a teen mother taught me about the enduring relationship between sex and money, and between both of these and power. I often shock people when I tell them that 1957 was the year the United States had its highest teen birthrate since records have been kept. The post–World War II era was remarkable for its enforced ignorance about sexuality and its consequences, but even more so for its lack of career aspirations or even possibilities for girls and women. Not surprisingly, therefore, these were boom years for teen pregnancy.

An idealized nuclear family had been constructed with clearly defined gender roles—Mom as the homemaker (privileged white women, it should be pointed out, who looked like June Cleaver, ever cheerfully vacuuming the rugs in freshly ironed, full-skirted dresses and high-heeled pumps), Dad going to the office, and kids growing up adhering to their assigned role models. This is why I genuinely thought I’d be blissfully happy living behind my own freshly painted picket fence.

By the time I was twenty, my husband and I had three young children. I loved them dearly, and I can’t imagine life without them. Still, at that point I also knew having one more would put me over the edge. And that picket fence that had once seemed like the buttercream icing on the red velvet cake of my imagined domestic bliss? It was feeling more and more like it was fencing me in rather than keeping trespassers out.

But he important point is that even if I had wanted to change the situation and break the rules of expected behavior, I couldn’t have done so because I had no employable skills, which meant few employment opportunities. I also had no reliable way to prevent pregnancies, making it impossible to work steadily even if there had been laws and policies then, as there are now, to keep employers from discriminating against fertile females, let alone women who were pregnant. Even the most stunningly talented women were held back. Future Supreme Court Justice Sandra Day O’Connor, graduating third in her class at Stanford Law School, had a hard time finding a job other than as a secretary. When the late Nobel-winning economist Paul Samuelson quipped that “women are just men with less money,” he was speaking from this frame of reference. That succinct, perhaps flippant phrase nailed the patriarchal culture’s outlook on the gendered economy perfectly.

Suddenly, in 1960, the world changed for me and so many other women like me when the birth control pill was introduced in the United States. It was like taking a big gulp of fresh air after holding my breath for too long. The pill allowed me to continue my education and eventually finish college, which in turn gave me the ability to earn my own living, contribute to the family income at first, and later to be the full support for myself and my children. The power to control my fertility—to determine when and whether I would have children—preceded and enabled my power to follow my own career and financial path, which in turn enabled me to have greater power in my personal relationships.

It became obvious to me that for a woman to achieve full, meaningful equality, to be able to determine her own destiny in the world, to “call herself free,” as Margaret Sanger put it, she must first and foremost be able to determine her own reproductive destiny. She must have moral autonomy over her body and her childbearing decisions. And to be able to have moral autonomy over the rest of her life, she must also have financial resources that she owns and controls.

From the book No Excuses: 9 Ways Women Can Change How We Think about Power by author, activist and former president of Planned Parenthood Federation of America, Gloria Feldt.  Excerpted by arrangement with Seal Press, a member of the Perseus Books Group.  Copyright (c) 2010.