Until now, it was thought that Holocaust deniers and global warming deniers were linked only by analogy, alike in their ability to ignore overwhelming evidence, science, and logical reasoning. There was no notion that global warming deniers actually are Holocaust deniers, or vice versa.

But meet Nick Griffin, Chairman of the right-wing British National Party, an elected member of the European Parliament, and a delegate for that body to the United Nations Copenhagen Conference on Climate Change. Although the delegation officially endorses strong, swift action to combat global warming, Griffin, who has called climate change a "hoax," an "unproven theory," an "elite scam," dissents. He will be allowed to speak as a duly elected member of the delegation.

In 1998, Griffin was convicted of violating British law against publishing racially inflammatory material for having written that, "I am well aware that the orthodox opinion is that six million Jews were gassed and cremated and turned into lampshades. Orthodox opinion also once held that the world is flat." He received a fine and a suspended jail sentence.

The point is not that Holocaust deniers and global warming deniers are overlapping groups with common members. Let us hope, let us posit, that there are not many like Nick Griffin. No, the usefulness of the Griffin case is to throw a spotlight on the type of mind that is capable of denying what is obvious to virtually every thoughtful person who has looked at the same evidence, science and logic. What kind of a mind is that? Griffin offers us a double-dose sample.

Is it a stupid mind? Not Griffin's. He seems well educated and bright.

Is it a crazy mind? Not Griffin's. He is lucid and follows normal conventions of speech and behavior.

Is it an exceptionally brilliant mind with an insight that has eluded others, á la Galileo Galilei, Issac Newton or Albert Einstein? Not Griffin's. He has no theory of his own, and should he point to the handful of contrarian scientists who do have theories - the sun-spotters, the it-happened-beforers, the volcano-dusters, et al. - let's just note that their lack of evidence has severely hobbled their attempts to follow in the footsteps of Galileo, Newton or Einstein.

Is it a political charlatan's mind? Maybe Griffin's is. He has devoted his life to gaining political power. Like Holocaust denier Mahmund Amadinejad of Iran, he knows how to tell an outrageously false story to attract political attention. Griffin's Holocaust denial kept him in the limelight for a while years ago, but it became a political liability and he dropped it. His global warming denial may now serve the same purpose.

Is it a true believer's mind? This seems the best fit. Longshoreman and philosopher Eric Hoffer described the personality type in his 1951 classic "The True Believer." It is a type for whom belief systems are interchangeable, so long as they are radical and all-consuming. The beliefs themselves - fascist, communist, libertarian, religious, or whatever - are unimportant. What counts is that the system offer a vehicle to pull the person out of his insecurities, give expression to his suspicions and resentments, affirm his desires, and allow him to roar to the world that he is right and everyone else is wrong. Inconvenient facts are simply denied.

Hoffer writes: "It is the true believer's ability to shut his eyes and stop his ears to facts which in his own mind deserve never to be seen nor heard which is the source of his unequaled fortitude and consistency."