All the girls want to get married. That's one of the things that surprised me when I started volunteering at a crisis pregnancy center here in Washington, D.C.

At first I thought it was a hopeful sign — and in some ways it is — that almost all of the women I counseled eagerly looked forward to marriage.

But the way they thought about marriage made it extremely unlikely that they would ever attain their goal. And my clients' conception of marriage is the same one most Americans hold today. The inner city is just an intensified, unsheltered version of the mainstream. This mainstream view of marriage appears to be exalted and romantic but actually leads to shaky, halfhearted, very-much-unromantic sexual partnerships.

The women I counsel often say they plan to get married when things are more together in their lives: when they're financially stable, when they're more sure about what kind of person they want to commit to, when they're older. Some of these impulses are obviously right. Emotionally immature people (like most American teen-agers) probably have no business making lifelong commitments. The women I see view marriage as so important that they want to be completely prepared before they enter into it.

Here are four problems with this seemingly commonsensical worldview.

First, if you're not ready to make a lifelong commitment to another person, why are you having sex with him? I sometimes tell my clients about a line from the movie Vanilla Sky: “Don't you know that when you sleep with someone, your body makes a promise — whether you do or not?”

We can talk about this fact in the philosophical terms of Pope John Paul II's theology of the body or we can just talk about the obvious possibility of pregnancy; no matter how you phrase it, sex is commitment, and if you're not ready for commitment you're not ready for sex. To deny this fact requires an alienation from one's own body and from one's most intense desires for a connection that goes beyond the physical.

Second, if you wait for marriage until you're financially stable, in many D.C. neighborhoods you'll be waiting forever. The money-first view of marriage leaves poor women in an especially vicious trap: They can never earn enough to buy a marriage.

Third, marriage isn't the reward you get for exiting poverty. It's a key that can help you exit poverty. Studies have found over and over again that married couples earn more and share resources more effectively. That's not just true for middle-class or wealthy couples; it's true for all income levels. (The best source for stats is probably Maggie Gallagher and Linda Waite's The Case for Marriage.)

These women say marriage is so important they need to be completely prepared first. Here are four reasons they're wrong.

And finally, nobody is ever ready for marriage. We can prepare ourselves; we can try to shape ourselves into responsible adults who choose good spouses. But in the end, life smacks everyone upside the head. The “marriage last” worldview is one in which we should only make commitments when everything's exactly in place, when we're stable, when we're totally prepared. Ironically, that worldview itself fails to prepare us for the times when things go haywire — when our stable, prepared lives derail.

The recent movie The Secret Lives of Dentists illustrated this point with its wrenching portrayal of a husband dealing with his wife's adultery and his children's illness. The Hursts did everything right, as far as we can tell. They're wealthy, they have good careers, they can spend weekends in their cozy country home. They have what the women I counsel are waiting for.

But they're not prepared. They're still forced to rely on commitment in the face of trouble, unpredictability and risk. Their lives can still be turned upside-down.

The same dynamics that have devastated the inner city are at work in Ivy League universities and corporate boardrooms. Collegiate women postpone marriage and childbearing until their educations are done or their careers are stable (which, for women who do postgraduate work, can be a very long time).

They, too, have sex while denying the degree of commitment that act entails; that's why Planned Parenthood sets up shop just outside every campus. They, too, believe that marriage is so amazing and heroic that they won't be ready for it until they're much, much older. They, too, believe that preparedness is prior to and more important than a commitment of lifelong love.

The best preparation for marriage is the realization that marriage is a lifelong commitment and the most stable, loving and — yes — romantic context for sex. Any other preparation is at best secondary, at worst distracting.

Eve Tushnet writes from Washington, D.C.