As regular readers know, I seldom review books in these columns, preferring to leave that important job to professional reviewers. But every once in a while a book comes along that illuminates a major political problem so effectively that I cannot resist calling it to the attention of thoughtful readers. That is the case with Tom Bethell's "The Politically Incorrect Guide to Science," recently published by Regnery.

As Bethell points out in an introduction, science is forever being used, like everything else, to reinforce political viewpoints. Normally, an advocate using something to support his point of view is promptly countered, more or less effectively, by an opponent citing something else that contradicts it. The rest of us can listen, with the help of the media, and decide for ourselves which viewpoint is better supported and therefore deserves to be believed.

But, Bethell notes, "Scientists seem to enjoy a measure of immunity." If a statement is made by a scientist in his professional capacity, non-scientists are afraid to contradict him. Even the media, whom we can usually count on to report opposing points of view, seldom look for information contradicting what a seemingly impartial scientist has declared to be the case.

Unfortunately however, scientists are human like the rest of us, with their full complement of opinions and biases on all sorts of subjects not squarely in their field of expertise. And not surprisingly, a lot of them are happy to rely on their reputations as unbiased experts to promote political causes of one sort or another. In many cases, they don't even recognize what they are doing; they simply confuse what they know with what they want.

So Bethell has written an entire book to expose some of the liberal myths that are forever being foisted on us with the important help of scientists, who are forever laying down the law without ever being effectively challenged by the media.

The current spectacular example, of course, is "global warming," and Bethell addresses it in Chapter 1. All serious proposed remedies for this supposed peril involve cutting down on economic activity. In the case of the United States, Bethell states, the Kyoto protocol (which this country refused to sign) would have required U.S. emissions of so-called "greenhouse gases" to be cut so much that "economic depression would have been the one sure result." That wouldn't bother the world's liberals and socialists much, of course, since they enjoy inconveniencing Uncle Sam. And many scientists (though by no means all) went along.

But Bethell's book has 13 other chapters, each exploding the phony "science" behind some other liberal shibboleth. Think nuclear power is dangerous? By artfully playing on the confusion between nuclear power and nuclear weapons, activists have crippled the use of "the safest of all energy sources," and vastly increased the use of heavily polluting coal-fired power plants (Chapter 2). Worried about DDT thinning the shells of endangered eagles? It doesn't -- but a million people a year are dying of malaria in Africa alone for lack of it (Chapter 5). Convinced that the theory of evolution is essentially sound, and that critics of it are just wacky creationists? The truth seems to be that the origins of species are far more complex than simplistic Darwinists will admit (Chapter 14).

And so it goes. In a chapter of "Final Thoughts," Bethell calls attention to what is easily the biggest single incentive for the scientific exaggeration of many alleged dangers: federal funding. In 2005 the budget of the National Institutes of Health was $28.8 billion. Enormous sums are spent every year on what some scientist has decided is a new danger to public health. But how much do you suppose Uncle Sam would squander on a scientist who demonstrated that in fact it wasn't a danger?

As Michael Crichton declared two years ago in a lecture at Caltech, "Rather than serving as a cleansing force, science has in some instances been seduced by the more ancient lures of politics and publicity." In this book, Tom Bethell is calling it back to its true responsibility.