Did the Holocaust happen? For many if not most people, the answer to this question is an easy "yes." But there are a few who insist "no," that the Holocaust did not happen and that there was no systematic, organized effort to exterminate the Jews in Europe. Why do people argue this, and who are they? Are they truly the skeptics they claim to be, or are they using skepticism as an excuse to pursue some other agenda?

The answers to those questions are the topic of a recent book by Michael Shermer and Alex Grobman. Because Holocaust denial makes semi-regular appearances in the news and historical studies, it is a good idea to understand what it is and why it is mistaken. But this book does more than simply explain Holocaust denial and refute it. In the process of explaining what the Holocaust is and why we can say that we know it happened, the book also explains how we might know if anything in the past happened or not.

The idea that the Holocaust really did happen may not sound like a very interesting thesis - but would you be able to refute any of the arguments of a Holocaust denier? The Holocaust is like the idea that the earth is round - everyone accepts it, but not everyone can easily prove it.

What is Holocaust denial? It is the activity of rejecting the standard historical view that there was an organized and systematic attempt to eliminate all Jews in Europe. Deniars argue that the numbers of deaths have been exaggerated, that gas chambers were used for the purpose of delousing rather than murder, that Hitler intended to simply deport the Jews rather than kill them, and that most of the actual deaths were due to hard conditions at the camps - often created or exacerbated by Allied war efforts.

The specifics of why all of these allegations are false is beyond the scope of this review, but it is worth looking at the authors' general approach to historical inquiry. Just how is it that we can ever know anything that happened in the past, whether it is the Holocaust or something else? The authors argue that we can claim historical knowledge in the same ways that we can claim knowledge about the natural world around us: through the convergence of evidence.

What sorts of data do we have? Historians can rely upon written documents, eyewitness accounts, photographs, the camps themselves, and inferential evidence from other sources. Taken together, they all reinforce each other independently - thus, even if all eyewitness testimonies could be shown to be false (a favorite tactic of deniers), that would not impact all of the other independent pieces of evidence.

For such reasons, denial of the Holocaust is much like the denial of something in science which has been confirmed by multiple lines of independent evidence, such as evolution. Just as creationism, which is presented as opposition to evolution, is nothing more than a psuedoscience, so, too, is Holocaust denial nothing more than pseudohistory.

If the book were nothing more than an explanation of the Holocaust, it would still be very useful, but it would also probably be a bit dry and boring. Fortunately, the authors avoid that trap with one of the questions in their subtitle: just who are the people who deny the Holocaust, and why do they do it? With that, the authors explore the psychology of deniers, explaining what they really believe and where they are coming from.

And, just as their exploration of how we know the Holocaust happened was part of a general introduction to how we can know anything about history, their exploration of deniers is part of a general introduction to extremists of any sort. No matter what part of the political or social spectrum they come from, extremists share a number of interesting and key characteristics in common.

Of particular importance is the fact that their extremist ideology provides a "life script" to the person. This script gives emotional meaning to the extremists, putting them in a dramatic role where they matter, and giving them the possibility of a cause in which Good battles Evil:

The reasons why people engage in holocaust denial are varied, but among the Holocaust deniers a very common theme is "the Jews" - it doesn't matter what the actual content is, so long as something negative is being said about Jews. Their anti-semitic orientation is quite plain, and so the motive of anti-semitism cannot be ignored when examining their revisionist works.

Even David Irving, who is perhaps one of the most scholarly of the deniers, seems to be preoccupied with "the Jews," complaining about their attempts to silence him. He has referred to them as "our common enemy" and has even sung to his young daughter the song "I am a Baby Aryan / Not Jewish or Sectarian / I have no plans to marry / an Ape or Rastafarian."

Shermer and Grobman through this book reveal that Holocaust Denial is not skepticism, and that the revisionists are not being genuinely skeptical. Honest skepticism involves an inquisitive attitude which, as far as is humanly possible, is not marred by political or ethnic prejudices. Skepticism also involves a willingness to follow the evidence wherever it leads, rather than ignoring that which does not fit preconceived desires.