The book is basically structured in six case studies, dealing with: (i) The tobacco industry’s attempt to discredit scientific evidence showing a direct link between smoking and lung cancer. (ii) The attempts to deny or downplay the harmful effects of acid rain. (iii) The debate over the hole in the ozone layer and its connection to CFC gases. (iv) Is secondhand smoking dangerous? (v) The campaign to question global warming and its origin in industries and technologies based on fossil fuels. (vi) Attempts to rewrite history in order to rehabilitate DDT and put doubt on the environmental hazards of its use.

Many of the scientists who are best described as "merchants of doubt" were also cold warriors with a background in physics and connections to the military, the most important of them being Frederick Seitz, Fred Singer, Robert Jastrow, and William Nierenberg. In the story told by Oreskes and Conway, these are the worst of the bad guys, corrupted scientists who attacked science in the name of capitalism and individual freedom; the "individual" being multi-billion dollar corporations. Incidentally, readers should know Jastrow (1925-2008) not only as an astrophysicist but also as the author of the apologetic God and the Astronomers, a popular book in which modern cosmology is used as an argument for divine creation. His views on science and religion were no less controversial than his views on science and environmental hazards.

As detailed by Oreskes and Conway, these merchants of doubters relied on bad science or non-science (some might say "out and out lies") in outrageous attempts to undermine good and reputable science. However, if we are to believe Seitz, Singer and their allies, they are crusaders of true science, using "sound science" to fight politicized science that threatened the financial bottom line of giant corporations whenever environmental and health issues were at stake.

Science has today an enormous epistemic authority, often reflected in a corresponding social authority. Characteristically both camps – established science and the sceptics – appeal to the authority of science and accuse their antagonists of misusing science. As one report, issued by a British pro-tobacco organization, put it: "Everything therefore depends on science. And with so much at stake, the pressure to adjust, shave, create, ignore, reevaluate, even manipulate, is enormous" (p. 166). There is in this regard some similarity to the use and/or misuse of science in scientific creationism and intelligent design. Contrary to the old version of Biblical fundamentalism, scientific creationists persistently claim that their conclusions are based on scientific reasoning and evidence, not on religious dogmas.

Merchants of Doubt insists that the described cases are about good science being attacked by scientists using bad science. But how to distinguish between the two? Understandably, the book includes considerations of what constitutes good science and recommendable scientific conduct. The authors correctly point out that the public (including most journalists) have only the vaguest understanding of science and how it works. For example, they expect scientists to deliver hard facts and factual conclusions with 100% certainty, which unfortunately is something the empirical sciences cannot deliver. Perhaps especially in the U.S., science is also expected to give room for "both sides," as if the democratic idea of equal time applies to the scientific process, as if science is a democracy. But as Oreskes and Conways make clear, science is not about opinion but about arguments and evidence, and for this reason (among others) it makes no sense to demand "a balanced view" where the "losing side" is given equal representation in cases where consensus has been achieved. Science is not democracy. The two authors have an almost unlimited faith in the established norms of science and in particular in the peer review system, which they see as a crucial element in how to obtain accepted scientific knowledge. By contrast, the merchants of doubt avoid peer review and for the most part publish their "anti-science" in journals which do not embrace peer review as a criteria for publication.

While I do not disagree with Oreskes and Conway in their general characterization of good versus bad science, I find it problematic to follow their claim that it borders on non-scientific behaviour to question a consensus view which has been established by the scientific community. According to their view: When a case has been closed, it should remain closed. If a knowledge claim is rejected, they say, "the honest scientist is expected to accept the scientific judgment and move on to other things" (p. 269). It seems to me that this attitude of Oreskes and Conway tends to exclude heretics and original thinkers from the realm of science. Science should not be a popularity contest requiring uniformity of thought. The nature of a true scientist is to question and to employ the scientific method to explore new possibilities. The history of scientific revolutions is replete with examples of heretics who hve overturned "conventional wisdom" and ushered in paradigm shifts. The dustbins of history overflow with discredited ideas which had been held sacrosanct, one of the most famous of which is the belief in the "Earth-centered solar system."

Fortunately there are scientists, even honest scientists, who have little respect for consensus and do not automatically accept established scientific knowledge. However, we must distinguish between scientists who honestly reject consensus and those who are paid to lie.

Unfortunately, in embracing a very conservative view of science, Oreskes and Conway, seem to mirror the attitudes of those scientists who wish to crush those who disagree with them, or their corporate masters. For example, according to Oreskes and Conway, global warming is as well established as the Earth’s revolution around the Sun. It is a closed case, meaning that a paper denying global warming will and should be rejected by peer-reviewed journals, just as will a paper arguing that the Sun orbits the Earth. But if these standards had been maintained at the time of Copernicus, wouldn’t his work on the heliocentric world system have been dismissed? After all, by 1543 it was universally accepted scientific knowledge that the Earth stays immobile in the centre of the universe. By this analogy, if evidence of global cooling began to surface, should this work be denied publication? Science should not a popularity contest where the most votes win.

While some of the more general claims made by Oreskes and Conway can be disputed, their analysis of how some American scientists produced counter-science and campaigned to mislead the public cannot. Merchants of Doubt is important from both a scientific and political point of view. In addition, it is eminently readable. However, readers should be aware that it was not only the scientists of doubt who had political agendas. The book under review has a clear political message and orientation. The authors write not only as scholars, they write also as advocates of a cause.