Deborah Lipstadt is Dorot Professor of Holocaust Studies at Emory University. She is the author of the forthcoming "Antisemitism: Here and Now," from which this essay is drawn in part. The views expressed in this commentary are solely the author's. View more opinion articles on CNN.

(CNN) Mark Zuckerberg, Facebook's CEO, recently described Holocaust denial as people who have simply gotten things "wrong" but not "intentionally" wrong. After all, he insisted, "I [also] get things wrong." He will not remove their posts from Facebook, "if they get things wrong, even multiple times." In the same interview, he points out that he himself is Jewish and he will not ban Holocaust deniers, just as he has not banned the conspiracy site InfoWars.

What Zuckerberg fails to understand -- even though he claims this was not his aim -- is that by saying deniers aren't "intentionally" getting things wrong, he leaves open the possibility that they could be right. For someone with Zuckerberg's massive profile and platform, this is breathtakingly irresponsible. Holocaust denial relies on such a robust set of illogical untruths that it is only possible to be a denier on purpose, contrary to what Zuckerberg says, intentionally.

For deniers to be right, who would have to be wrong? Survivors would have to be wrong -- as well as bystanders, those non-Jews who lived in the cities and villages in eastern and western Europe and watched their Jewish neighbors being marched away to be shot and killed in freshly dug ditches in the woods. The scores of historians who have studied the Holocaust since 1945 would either have to be part of a massive conspiracy or have been completely duped.

But, above all, the perpetrators, some of whom have admitted their guilt , would have to be wrong. How can deniers explain that in not one war-crimes trial since the end of World War II has a perpetrator of any nationality denied that these events occurred? They may have said, "I was forced to kill," but not one asserted that the killing did not happen.

Finally, why has Germany shouldered the enormous moral and financial responsibility for the crimes committed in the Holocaust, if it did not happen? According to deniers, there is a simple answer to this question: German officials were forced into a false admission of guilt by "the Jews," who threatened to prevent Germany's reentry into the family of nations.

But this, too, makes little sense. German leaders knew that admitting to genocide would impose upon the nation a horrific legacy that would become an integral part of its national identity. Why would a country take on such a historical burden if it was innocent, under any circumstances? Moreover, it's now been 70 years since the end of the war and Germany is now a global political and economic leader. It could easily say now that "it's not true; the Jews made us say this back in 1945." Instead, the German government created a massive memorial in Berlin to the murdered Jews of Europe that opened in 2005

Deniers rely on yet another bit of illogic. Often they demand to be shown Hitler's written order authorizing the murder of all of Europe's Jews. In all likelihood, there is none. Hitler realized the folly of affixing his signature to such an order, which, had it become public, might have caused him many problems. More important, historians are untroubled by the absence of such a document. They never rest their conclusions on one document, particularly in this instance, when there is a vast cache of evidence attesting to a government-directed program of mass annihilation. Deniers, of course, insist that "the Jews" have forged these documents. But if that were the case, why didn't they also forge the Hitler order?

The list of illogical arguments goes on. Deniers contend that had the Third Reich, a regime they describe as the epitome of efficiency and power, wished to murder all the Jews, it would have ensured that no witnesses remained alive to testify about the death camps. Therefore, the fact that there were survivors alive at the war's end constitutes proof that there was no genocide and that the survivors' testimonies are lies. The fallacious nature of this argument is self-evident. The Third Reich was also intent on winning the war, which it did not do. Therefore, the assumption that the Third Reich succeeded at all it set out to do is false. Anything based on that premise is equally false.

Deniers are a new type of neo-Nazi. Unlike previous generations of neo-Nazis -- people who celebrated Hitler's birthday, sported SS-like uniforms, and hung swastikas at meetings where they would give the Sieg Heil salute -- this cohort eschews all that. Wolves in sheep's clothing, they don't bother with the physical trappings of Nazism -- salutes, songs, and banners -- but proclaim themselves "revisionists" -- serious scholars who simply wished to correct "mistakes" in the historical record. This is extremism posing as rational discourse. And his statements suggest that Zuckerberg has been duped by them into thinking that they're any different than someone who proudly wears a swastika.

People generally differentiate between facts and opinions -- as the saying goes, you can have your own opinions, but not your own facts. But in the case of deniers, there are facts, opinions, and lies. In 2000, when I was on trial in London for libel, having been sued by David Irving -- then one of the world's leading Holocaust deniers -- for having called him a denier in one of my books, my defense team tracked all of his "proofs" back to their sources and found that imbedded in each of his historical claims was a falsification, invention, distortion, change of date, or some other form of untruth. Once these lies were exposed, his arguments collapsed.

Holocaust denial is not about history. A form of antisemitism, it's about attacking, discrediting, and demonizing Jews. The deniers' claims -- that the Jews planted evidence, got German prisoners of war to falsely admit to crimes, and forced post-war Germany to shoulder a tremendous financial and moral burden -- are predicated on the notion of the mythical power of the Jews, which was extensive enough to realize this vast conspiracy. These assertions rely on classic antisemitic tropes, some of which are over 2,000 years old.

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Deniers, who today clearly feel more emboldened than ever before, are not the equivalents of flat-earth theorists, nor are they just plain loonies. As a person who created and provides a platform for the dissemination of information on an awesome scale, Zuckerberg must recognize that theirs is not a cognitive error or a regrettable misinterpretation or failure in judgment that can be rectified by showing them documentation or evidence. They are white supremacists and antisemites. Their agenda is to reinforce and spread the very hatred that produced the Holocaust.