BOOK REVIEW : Historian Takes On Ranters, Ravers of ‘Holocaust Revisionism’ : DENYING THE HOLOCAUST: The Growing Assault on Truth and Memory, <i> by Deborah E. Lipstadt</i> ; Free Press; $22.95, 300 pages

Whenever I happen to mention the Holocaust in a book review, some attentive but anonymous reader always mails me a curious little pamphlet that suggests the genocide of 6 million Jewish men, women and children never actually took place.

To that reader--and to anyone who has been exposed to the weird phenomenon of “Holocaust revisionism”--I commend “Denying the Holocaust” by Deborah E. Lipstadt.

Holocaust revisionism is a kind of moral and intellectual virus that has spread from the crackpot fringe to the very heart of public discourse in the media, the courts and the universities around the world. Lipstadt’s book is an antidote to the virus, a dose of strong medicine that is intended to restore some sanity to the study of what did and did not happen to the Jewish people and the other victims of Nazi brutality during World War II.

The “Holocaust-deniers,” as Lipstadt dubs them, approach the study of history with an attitude that derives in equal parts from “Alice in Wonderland,” the Flat Earth Society and the Big Lie techniques as practiced by the Nazis themselves.

The Holocaust, the deniers insist, is a vast historical fraud devised by a cabal of “Talmudists and Bolsheviks,” a “gigantic politico-financial swindle whose beneficiaries are the state of Israel and international Zionism.” Even “The Diary of Anne Frank,” say the deniers, is a semi-pornographic forgery. The whole point of the conspiracy, they insist, is to “make Germany an ever-lasting milk cow for Israel.”

The reality, say the Holocaust deniers, is that Auschwitz offered “all the luxuries of a country club,” and the gas chambers were really delousing facilities: “Only Lice Were Gassed in Auschwitz” is the headline of one revisionist article in a French newspaper. And if Jews died at all, the deniers insist, it was only because Allied bombing cut off the line of supply to the concentration camps.

“Denying the Holocaust” considers the cracked historical arguments that are put forward by the deniers, and neatly debunks each and every one. Lipstadt shows how the deniers cook up phony evidence while ignoring the voluminous testimony of survivors, eyewitnesses and self-confessed Nazi war criminals. And she patiently unravels the web of half-truths and outright lies that amount to an international propaganda crusade.

Lipstadt, a historian and a professor of religion at Emory University, is also the author of “Beyond Belief,” a study of what the Allies knew about the Holocaust and when they knew it. With her second book, Lipstadt establishes herself as a leading historian of “second-generation” Holocaust studies--and, ironically, she shows us the healthiest kind of revisionism in the study of history.

Notably, Lipstadt herself refuses to dignify the Holocaust deniers with the badge of revisionism because they do not revise history; rather, they falsify it and, ultimately, they obliterate it.

“I abjure the term revisionist because on some level revisionism is what all legitimate historians engage in,” she writes. “But it is built on a certain body of irrefutable evidence: Slavery happened; so did the Black Plague and the Holocaust.”

“Denying the Holocaust” can be approached as a work of investigative journalism--Lipstadt unravels the linkages that suggest the conspiracy theorists are themselves a kind of international conspiracy of misinformation. Along the way, she performs the essential function of telling the truth about the Holocaust.

But at the heart of her book, Lipstadt is asking us to think about the fundamental meaning and function of history and memory: “What do we really know about the past,” she prompts us to consider, “and how do we know it?”

“These attacks on history and knowledge have the potential to alter dramatically the way established truth is transmitted from generation to generation,” she writes. “Denial of the Holocaust poses a threat to all who believe that knowledge and memory are among the keystones of our civilization.”

Lipstadt goes on to suggest that the Holocaust deniers are so repugnant, so vile and so malicious that they should be excluded from public discourse and consigned to the ranks of the ranters and ravers.

“Let this point not be misunderstood,” she writes. “The deniers have the absolute right to stand on any street corner and spread their calumnies. They have the right to publish their articles and books and hold their gatherings. But free speech does not guarantee them the right to be treated as the ‘other’ side of a legitimate debate.”

On this point, I think, Lipstadt is wrong. As Lipstadt shows us, the Holocaust deniers have insinuated themselves into classrooms, Op-Ed pages, talk shows, courtrooms and computer bulletin-boards, and they have become too dangerous to be ignored or dismissed--they must be squarely and clearly repudiated.

And that, of course, is precisely what Lipstadt does so convincingly in “Denying the Holocaust.”