"Married: A Fine Predicament," by Anne Roiphe, Basic Books, 285 pages, $25.

At the end of her new book, "Married: A Fine Predicament," Anne Roiphe delivers an open letter to her daughters, laying out a battle plan for a happy marriage. "I know you don't want to hear from me on this subject," she writes, "but this is my book and you can't stop me."

Her own unmarried children might say "Stop," but other singles are likely to pick up the book and grudgingly say, "Okay, go on, I'm listening."

"Married" is a hodgepodge of sometimes clever, sometimes frustrating thoughts on a clever and frustrating institution. Its framing device is Roiphe's own maternal anxieties as her daughters approach middle age unattached. Its target is clear - the "mass of unwed 30-somethings," who she worries are doomed to miss out on a joyful, perhaps essential, part of life if they continue on their current uncommitted courses.

While the target of "Married" is clear, however, its goal is not. If you were to read it as a self-help tract you would find it more painful than helpful. If you were to read it as a memoir you would feel cheated because of the way it finesses intimate details. But contained within these shortcomings is Roiphe's own hard-won understanding of marriage. That understanding is worth knowing.

Roiphe comes to express her conclusions through a kind of triangulation between her disastrous first marriage to an egocentric playwright, the limbo lives of her unmarried daughters and her happy second marriage to an Upper West Side psychoanalyst. Examining these three conditions of modern urban life, she presents us with our choices. We can marry hastily for the sake of drama and unexamined passion that in the end "can be like being boiled alive."

We can pull back from marriage altogether and emptily extend our adolescence, or we can be thoughtful and wise and work our way into that rare, happy betrothal that "better than any solution yet divined can assuage our loneliness."

The problem with the book lies in the padding - the hazy overviews, the pop-culture meanderings. The Terry Gross "middle mind" excoriated so well in Harper's Magazine earlier this year comes to mind.

Roiphe starts out her sections with gripping accounts of the painful ending of her first marriage and the strain a sick child placed on her second. But before long she ends up drawing comparisons to "Bridget Jones's Diary," "Sex in the City" and Tony and Carmela Soprano's disconnect in the sack.

Some of Roiphe's bolder noshes propose:

* That shacking up, slacker-style, without a formal commitment is cowardly, unproductive and "uncool" and can lead to as much unhappiness as a bad first marriage.

* That infidelity, even when put in the context of a so-called "open marriage," renders a marriage moot.

* That good parents do know what's best for their children and therefore arranged marriages might not be such a bad idea.

* That there are inherently bad, unloving single people, dead on the inside, charming on the outside, shopping their wares on the dating market. Even years of yoga, meditation and psychotherapy won't make them fit for the huppah.

All of this is conveyed wisely, with a gravitas that only a life spent in marriage can produce. The greatest wisdom of this book, however, may be what is not on the page. Ultimately a good marriage may be an unprovable premise.

It may be, as Leo Tolstoy said, that all happy families are alike. It may be that only the unhappy ones are worth talking about because each one is so specific.

By arrangement with the Forward.