Stability: the simple word that debunks arguments against the family

''How's the family?'' It depends on whom - and how - you ask. Asked among friends, the question may show little more than passing interest. But asked of sociologists, it calls forth profound responses. And rightly so. ''The family,'' after all, is one of humanity's precious assets.

So how is it doing?

* ''Poorly,'' say the more pungent reformers of the past few decades - who, viewing traditional family structures as obsolete, irrelevant, or cumbersome, would happily see them fade away.

* ''Quite well, thank you!'' retorts the pro-family camp, which sees the institution surviving an onslaught of attack.

* ''We're not sure,'' say the academicians, bureaucrats, and family-service providers who analyze the institution.

All three groups have studied the family for years. Now, in turn, all three are being studied. Brigitte and Peter Berger, a husband-wife team of sociologists at (respectively) Wellesley College and Boston University, have even given them names. They call the three camps the ''critics,'' the ''neo-traditionalists,'' and the ''professionals.'' Their sharp-eyed analysis of these groups forms the basis of a probing and provocative new book titled ''The War Over the Family: Capturing the Middle Ground'' (Anchor/Doubleday, New York).

The title suggests their thesis - that we are locked in serious battle over the nature, function, and future of the family. The subtitle points to their position: that there is ''a middle ground toward which most people instinctively gravitate in matters concerning the family'' which is the ''most plausible intellectually'' of all the alternatives.

That ground, the Bergers argue, is emphatically not occupied by the ''critics ,'' who, in the name of freedom, preach freedom from the family. Coining the term ''antinatalism,'' the authors describe a constellation of contemporary attitudes that militate against childbearing: the ''endless self-realization'' of the ''swinging single'' life, the ''idealization of abortion,'' and the ''insistence that a 'gay life style' is as socially legitimate as heterosexual marriage.'' Going further, they place these attitudes within a larger configuration of antifamily feelings which include ''political leftism, zero-growth and zero-population sentiments, pacifism, . . . a deep suspicion of patriotism, . . . and a generally negative attitude to the values of discipline, achievement, and competitiveness.'' It is a sweeping indictment - broader, perhaps, than it needs to be, and guaranteed to outrage a wide spectrum of American society.

The ''professionals'' come off little better. Their thrust, say the Bergers, is to demonstrate that ''the family (is) increasingly . . . incompetent to deal with its own problems'' - and must, therefore, have professional help. ''The professionals,'' they tartly observe, ''have an interest in defining situations in such a way that their services appear necessary.''

At heart, then, this is a book for the ''neo-traditionalists'' - citing chapter and verse of extensively footnoted sociological literature to bolster that cause. In the early sections of the book, the Bergers try (without great success) to maintain a tone of nonpartisan analysis. But their advocacy shines through. ''We have reached the conclusion,'' they write long before they conclude, ''that there is no viable alternative to the . . . family in the contemporary world. The values of that institution are among the great human achievements of our civilization, and as such they are worthy not only of respect but of a concerted practical defense.''

In the end, their defense is surprisingly simple. Of the many values families can provide, they say, child-rearing experts overwhelmingly agree that two things are absolutely essential: stability and love. That, ultimately, is what the family is for.

Surprising? Yes and no. Most of us, taught that romantic affection is precursor to the establishment of a family, agree on the importance of love. But stability? That commodity, depending as it does on continuity, steadiness, and even predictability, is in short supply just now. We hear of its lack at every turn. Unstable governments spark third-world turmoil. Unstable financial markets breed boom-and-bust cycles. Even tornadoes are said to arise from unstable air masses.

Which is precisely why a powerful argument for stability is so welcome these days. In three crisp sentences, this book cuts to the core of the relation between stability and family life. ''Social order,'' the authors write, ''is impossible unless the conduct of individuals is predictable. In human beings, predictability of conduct depends on the development of a stable character and of reliable habits. Everything we know about social psychology indicates that both have their origins in family life.''

The book has its faults: repetition, hasty prose, some half-cocked arguments, and enough provocation to make one's intellectual hair stand on end. But those are three fine sentences - worth thinking hard about, worth holding on to in a world that sometimes imagines it can survive without families.