THE MUCH HERALDED "nuclear debate" of the past few years has often seemed little more than a shouting match. The Jonathan Schells holler about the immorality of weapons build-ups and the inevitability of nuclear conflict, the Caspar Weinbergers shout back about the immorality of weakness and the inevitability of Soviet adventurism Neither side takes the other seriously, and neither--because of the absolute moral terms in which their "debate" has been couched--deigns to consider more moderate views. Meanwhile the public remains largely uneducated about the complexities of nuclear strategy instead, individuals take sides based on whether they fear more the gloom of a nuclear holocaust or the doom of Soviet hegemony.

Derek Bok convened a handful of Harvard scholars last spring in an attempt to raise the level of public awareness on the nuclear issue, and their product seems promising, indeed. Incisively and relentlessly, Living With Nuclear Weapons ploughs through the questions of the nuclear era. It provides more information on nuclear issues--from a history of the nuclear era to an analysis of America's strategic predicament to a discussion of current nuclear concerns--than any other book on the subject to date, and it does so crisply and logically.

Bok expected his Harvard Nuclear Study Group to stop there, having provided an objective report--a handbook on nuclear issues. It would have been as he describes it in his foreword, an analog to The Harvard Health Letter, a purely factual Medical School publication. But the debate over nuclear weapons is not like the debate over cholesterol: It cannot be decided empirically or discussed in a moral vacuum. So Derek Bok much more.

FIRST OF ALL, the six members of the study group--professors Albert Carnesale, Paul Doty, Stanley Hoffmann, Samael P. Hantington and Josheph S. Nye Jr, and graduate student Scott D. Sagan--tick off their views (and occasionally their differences) on any number of timely strategic issues. Most notably, they back the deployment of new NATO missiles in Europe, oppose a blanket "no first use" policy, and split on the construction of the MX missile. They also urge a partial nuclear freeze, oppose the B-1 bomber, and expose developing anti-ballistic weapons that could violate the 1972 SALTI accord.

Much more important, they gradually set forth a compelling alternative--moderate in its means and moral in its goals--to the unpalatable extremes of disarmament and massive rearmament that have dominated the public "debate" thus far. The argument goes something like this: The Jonathan Schells of the Left err in presuming an absolute choice between global peace and disarmament on the one hand, and global nuclear holocaust on the other. With the nuclear genie out of the bottle, it is all but impossible to put it back. Mankind cannot hope to "reinvent politics: to reinvent the world," as Schell proposed last year in The Fate of the Earth. National sovereignties are too entrenched and global consensus too elusive for Schell's "utopian vision" to be realized:

In the real world of sovereign states, a world government is a dream for the distant future, not a practical goal for current policymakers...It would be a tragedy if opportunities for practical progress toward nuclear peace were missed because our goals were set too high, beyond the reach of what is possible.

So mankind must, as the book's title suggests, learn to live with nuclear weapons while preventing their use--in other words, detersons. But the effectiveness of detainee cannot be measured in absolute terms, Cap Weinberger not with sinoding. Some weapons--and some theatric--can prove destabilizing. It is probably unwise, for example, that the U.S. should seek rough parity with the Soviet Union, eschewing new weapons systems that might either frighten or tempt the Soviets.

But deterrence needn't last forever; while maintaining crisis stability, the U.S. should be continually striving for longer-term security. Arms control efforts that do not destabilize the strategic balance, pursuit of "detente with our illusions," attempts to moderate Soviet policy and warm the present bipolar chill, and improved conflict resolution machinery are particular desirable. For as the study group concludes.

Nuclear deterrence can be tolerated, but never liked. Deterrence can be seen as a necessary evil. Because it is evil, one cannot abandon it carelessly; because it is evil, one must strive to rely on it less.

Thus, on the spectrum of views characterized by the term "deterrence," the Harvard study group seems to fall somewhere in the middle. Much of the Right, Weinberger included, perceives deterrence as a long-term moral good. Much of the Left, notably the Catholic bishops, perceive it as a short-term necessary evil to be disregarded as swiftly as possible. The study group sympathizes with the bishops' outlook but is willing to stick with deterrence far longer. Hence, its support of weapons systems--like the cruise missile--that the bishops oppose.

Of course, the group authorship of Living With Nuclear Weapons may well have contributed to its embrace of what might be called moderate deterrence. Had Huntington been in charge alone, the book might well have seen deterrence as a longer-term good. Had Hoffmann written it, a more minimal deterrent--short of today's expensive parity--might have prevailed.

But all in all, theirs is a sensible vision. The authors have taken extraordinary care in analyzing whether particular weapons or strategic policies are stabilizing or destabilizing under certain circumstances. Humanity, they observe, "must live with [nuclear weapons] carefully, vigilantly, gingerly, always displaying the utmost caution." Living With Nuclear Weapons bespeaks much the same prudent attention to detail that its authors would like to see among American policy makers.

BUT CAN this book--or any other--make a difference? Bok and the study group gambled that it could--that Living With Nuclear Weapons could educate a populace that has often been seduced by simple panaceas (chief among them Ronald Reagan). One hopes they are right, but two reservations should be noted.

The first is that Living With Nuclear Weapons is making a very late entrance onto a very crowded stage. Dozens of trashy nuclear books have flooded America since the early months of the Reagan Administration, and more important, many Americans have accepted polar positions that will prove hard to abandon. President Bok deserves much credit for being the catalyst of the finest nuclear study yet, but his efforts might have paid off better had they come sooner. Public education works best when it is both subtle and early. The belated Harvard presence--the white knight from Cambridge come to rescue the nuclear debate--could well invite scorn among its would-be readership.

The second reservation is that the nuclear debate is as complex as any in American political history. There is no single "nuclear issue," but many interrelated ones that it would be unwise to study in isolation. Living With Nuclear Weapons makes a valiant effort to shrink aspects of the nuclear debate to human dimensions. It employs frequent analogies--to duels, track meets, football games, horses, porcupines and staircases--and even includes a "checklist of arms control proposals" that is reminiscent of nothing so much as a Topps baseball card. But even it must descend into nuclear complexity, and sometimes it fails to emerge. Its analogies to the ancient Greeks are often apt, but are they accessible to a public that has not taken Gov 10?

Living With Nuclear Weapons may well have little practical impact: the disproportion between man's ability to eliminate nuclear arms and nuclear arms' capacity to eliminate man is the most tragic irony of the nuclear age. But if the first four decades of coexisting with nuclear weaponry proves anything, it is this: man cannot diminish the likelihood of nuclear holocaust until he comes to grips intellectually with the complexity of the problem and rejects the easy panaceas of both the Left and the Right. The authors of Living With Nuclear Weapons recognize this; perhaps one day they will be looked on as the men who brought the element of debate to the nuclear debate. That would be success enough.