OCCASIONALLY we read about a war that is supposed to be going on among philosophers. The war, we are told, is between those who believe in truth and rationality and those who do not. The latter -- the bad guys -- are sometimes called postmodernists, sometimes irrationalists and relativists, and sometimes social constructionists. The good guys believe that science tells us the way things really are; they take the paradigm of rationality to be scientific inquiry, just as the paradigm of truth is the result of that inquiry.

Good guys such as E. O. Wilson and Paul Gross ask us to see natural science as a model for other human activities. They are deeply suspicious of philosophers of science (including Bruno Latour and the late Thomas Kuhn) who describe conflicts between scientific theories in the same terms they use to describe conflicts between moral or political opinions. Wilson and Gross see a big difference between finding and making -- between efforts to learn how things really are and efforts to cobble together artificial entities such as commercial credit and constitutional democracy. Their insistence that natural science enjoys a special relationship to reality has been even more vociferous since the "Sokal hoax," a few years ago, when a scientist named Alan Sokal made fools of some postmodernist nonscientists by getting them to take a rubbishy bit of pseudo-science seriously.

Bad guys, like the people Sokal fooled, think that "postmodern philosophy" -- roughly, the anti-metaphysical doctrines common to Nietzsche, Foucault, Heidegger, and Derrida -- has "unmasked" science. Starting with the claim that homosexuality, the Negro race, and womanliness are social constructions, they go on to suggest that quarks and genes probably are too. "Ideology" and "power," they say, have infiltrated sterile laboratories and lurk between the lines of arcane journals of mathematical physics. The very idea of scientific objectivity, they say, is self-deceptive and fraudulent.

Members of a third group find themselves caught in the middle, agreeing that we might be better off without the term "objective reality" but thinking, too, that we could do without "social construction." They believe neither that science has a special relationship to reality nor that its pretensions need to be unmasked. The community of natural scientists is, they think, a model of intellectual rectitude, and yet its virtues -- willingness to hear the other side, to think through the issues, to examine the evidence -- have nothing to do with the fact that the objects natural scientists investigate are found rather than made. The same virtues, after all, are found among judges and classical philologists, who investigate objects that are made rather than found.

These philosophers can agree with the social constructionists that notions like "the homosexual" and "the Negro" and "the female" are best seen not as inevitable classifications of human beings but rather as inventions that have done more harm than good. But they are not sure that "X is a social construction" adds much to "talking about X is not inevitable, and there are probably better ways of talking." They see the point of Foucault's famous observation that in the nineteenth century homosexuality was "transposed from the practice of sodomy onto a kind of interior androgyny, a hermaphroditism of the soul." Foucault went on to say, "The sodomite had been a temporary aberration; the homosexual was now a species." They agree that we would have been better off with the commonsensical thought that some men prefer to have sex with other men than with the sophisticated attempt to ground this preference in a deep, dark psychopathology. But they think that the energy Foucault's disciples have put into arguing that something is a social construction would be better put into proposing some alternative social construction: a more effective and less damaging way of talking about what is going on. All our controversial ways of talking are, to be sure, choices that society has made about how to classify things. In that sense these classifications are of course socially constructed. But the interesting question is whether anybody can suggest a better classification.

IAN Hacking -- the most intellectually curious and imaginative philosopher of science now writing -- is a member of the third group. In this spirited and eminently readable book he suggests that the combatants climb down from the level of abstraction on which they debate such topics as the nature of truth, the nature of science, and the nature of rationality, and focus instead on three questions: Are the best scientific theories of our day the inevitable results of serious inquiry, or might science have taken a different turn and still had equal success in building bombs, say, or curing diseases? Do these theories tell us about the intrinsic structure of reality, or are they simply the best tools available for predicting and controlling nature? Are the longest-lasting and most frequently relied upon theories stable because they match a stable reality, or because scientists get together to keep them stable, as politicians get together to keep existing political arrangements intact? Philosophers like Latour and Kuhn, wary of the idea that reality has an intrinsic nature that scientific inquiry is destined to reveal, are inclined to say that science might have done as good a job if it had never come up with either quarks or genes. As they see it, scientific progress is like biological evolution: no particular life-form is destined to emerge, and lots of different ones might have turned out to be equally good at survival. In this view, scientific theories are tools that do a job. They do it well, but some other tools might perhaps have done the same job equally well.

As Hacking says, many scientists find this view absurd. He himself is dubious about it, but he is inclined to be even more dubious about the idea that reality has an intrinsic structure that science accurately describes. These latter doubts are aroused by the notorious, persistent, seemingly insoluble perplexities to which the notion of "intrinsic" gives rise. The most familiar of these is the question How can we ever hope to compare reality as it is in itself, naked and undescribed, with our descriptions of it? Many philosophers have given up on the notions of "intrinsic" and "in itself," as a result of their failure to answer that question.

The stalemate that Hacking brilliantly describes but does not try to break is between many scientists' intuition of the inevitability of quarks and many philosophers' suspicion that the claim of inevitability makes sense only if the idea of the intrinsic structure of reality makes sense. This teeter-totter between conflicting intuitions is, Hacking rightly says, a genuine intellectual problem. Which answer one gives to his third question -- about the source of the stability of the most reliable bits of science -- is likely to be a matter of which side of the seesaw has most recently descended.

These alternating intuitions have been in play ever since Protagoras said "Man is the measure of all things" and Plato rejoined that the measure must instead be something nonhuman, unchanging, and capitalized -- something like The Good, or The Will of God, or The Intrinsic Nature of Physical Reality. Scientists who, like Steven Weinberg, have no doubt that reality has an eternal, unchanging, intrinsic structure which natural science will eventually discover are the heirs of Plato. Philosophers like Kuhn, Latour, and Hacking think that Protagoras had a point, and that the argument is not yet over.

The most vocal and inflamed participants in the so-called science wars are treating the latest version of this fine old philosophical controversy as a big deal. In the very long run, perhaps, it will prove to be one. Maybe someday the idea of human beings answering to an independent authority called How Things Are in Themselves will be obsolete. In a thoroughly de-Platonized, fully Protagorean culture the only answerability human beings would recognize would be to one another. It would never occur to them that "the objective" could mean more than "the agreed-upon upshot of argument." In such a culture we would have as little use for the idea of the intrinsic structure of physical reality as for that of the will of God. We would view both as unfortunate and obsolete social constructions.

BUT there is no hurry, no urgent need to bring this perpetual seesaw to rest. Scientists who agree with Kuhn are not about to do anything very different from what their colleagues who agree with Weinberg do. Their disagreements come up only in after-hours chat, not during the daily grind in the lab. Analogously, politicians who think that human rights are somehow built into the ahistorical structure of the human soul usually propose the same policies as those who think that human rights are an admirable recent invention. In the short term, philosophical differences just do not matter that much. In neither science nor politics is philosophical correctness, any more than theological correctness, a requirement for useful work.

Hacking's book will help its readers understand why they need not worry that civilization will collapse if Nietzsche and Foucault continue to be taken seriously, and also why those who describe themselves as postmodern (by now a somewhat musty adjective) are not as radical, original, or relevant to moral and political deliberation as they sometimes think. The science wars are in part a product of deep and long-lasting clashes of intuition, but mostly they are just media hype -- journalists inciting intellectuals to diabolize one another. Diabolization may be helpful in keeping intellectuals aroused and active, but it need not be taken very seriously.

Hacking's book is an admirable example of both useful debunking and thoughtful and original philosophizing -- an unusual combination of good sense and technical sophistication. After he has said his say about the science wars, Hacking concludes with fascinating essays on, among other things, fashions in mental disease, the possible genesis of dolomitic rock from the activity of nanobacteria, government financing of weapons research, and the much-discussed question of whether the Hawaiians thought Captain Cook was a god. In each he makes clear the contingency of the questions scientists find themselves asking, and the endless complexity of the considerations that lead them to ask one question rather than another. The result helps the reader see how little light is shed on actual scientific controversies by either traditionalist triumphalists or postmodernist unmaskers.

Richard Rorty is a professor of comparative literature at Stanford University. His most recent book is (1998).

The Atlantic Monthly; November 1999; Phony Science Wars - 99.11; Volume 284, No. 5; page 120-122.