Debunking Denialism

The Intellectually Barren Wasteland of Holocaust Denial

Related: My Encounter with a Holocaust Denier, Exposing Holocaust Deniers’ Quote Mine of Historian Arno Mayer.

There are two fundamental objections that any conspiracy theory must pass in order to have a shred of plausibility even before we start discussing the specific details of the available evidence. Most conspiracy theories that have been proposed by proponents of pseudoscience (regarding topics such as 9/11, chemtrails, vaccines, evolution HIV/AIDS denialism etc.) fail one or both of these tests. These objections can be called the no-leak problem and the prediction problem. The no-leak problem points out that a vast conspiracy theory involving hundreds or even thousands of people is very likely to experience leaks to the public. If no such leaks have occurred, then it is likely that the conspiracy theory is false. The second problem can be referred to as the prediction problem. Reality is a collection of enormously complex dynamic systems and prediction is often very difficult, especially years and decades into the future. This means that there are huge risks associated with attempting to pull off the secret agendas believed by conspiracy theorists. If those risks are sufficiently high, it would be difficult to see why any shadowy organization would attempt it. If the operations failed, they would have been exposed and there is presumably a huge incentive for shadowy organizations to stay under the radar.

Holocaust denialism fails to counter any of the two objections. If the Holocaust was a conspiracy, then that would have to involve thousands of scientists, historians, soldiers, journalists and even members of the Nazis who did not deny the Holocaust. If that were true, something would have leaked during the past 70+ years, but no such leaks have been observed. Ergo, this is evidence against Holocaust denialism. Conspiracy theories about the Holocaust also fails the prediction objection: it is clearly very difficult to have predicted what would happen after WWII and certainly decades after Hitler started agitating against the Jews.

In My Encounter with a Holocaust Denier, I discussed the tactics and assertions made by a Holocaust denier I met in real life. Fortunately, he was not that sophisticated and his claims could easily be exposed as false. A while back, that post was posted on the Facebook page for Skeptics; Atheists; Realists; Agnostics; Humanists. Predictably, a Holocaust denier and other misguided individuals came creeping out of the shadows and posted a couple of comments (now hidden from view because that person was rightfully banned for spamming). No credible arguments were put forward of course, just the same old recycled garbage. Consider this blog post a take-down of those assertions.

The diversionary tactic of arguing from moral equivalences

One way that apologists for Holocaust denial attempt to minimize the Holocaust is by attempting to make moral equivalences to crimes carried out by western nations. Two classic examples are western imperialism and the Allied bombing of Dresden. However, such an approach is fundamentally flawed as the existence of other horrible crimes do not negate the one under discussion. At its heart, these kinds of dubious moral equivalences are just tu quoque fallacies.

Holocaust “revisionists” are actually Holocaust deniers

Holocaust deniers do not like being called Holocaust deniers. Instead, they prefer to be called Holocaust “revisionists”. However, these so-called “revisionists” are rarely interested in updating the mainstream historical account of the Holocaust as new facts emerge. Rather, the term is used to escape the negative connotations that the word “denier” has. It mirrors how creationists have attempted to change their label to “intelligent design proponent”, how anti-vaccine cranks are attempting to portray themselves as “pro safe vaccines” or “anti-toxin”.

The key realization is that most Holocaust “revisionists” still reject three of the most central aspects of the Holocaust: that there was intentionality for genocide primarily based on ethnicity, that a highly systematic extermination program using gas chambers were used and that roughly 6 million Jews were killed. If a person deny several of the central facts about the Holocaust, then that person is a Holocaust denier. No amount of wiggling or re-branding is going to change that.

Holocaust deniers also use a lot of the methods typical of denialism in general: quoting scientists out of context, confusing mechanism with facts, playing the martyr card, false balance, single study fallacy, false experts and so on. Thus, it is appropriate to label Holocaust deniers as denialists.

Holocaust deniers, not Holocaust historians, are the conspiracy theorists

When the fact that Holocaust deniers are conspiracy theorists are pointed out, they often retort childishly that the scientific skeptics are the real conspiracy theories because they hold that there was a plan to exterminate entire groups of people. This kind of illogical assertion is also often used by 9/11 truthers when they claim that individuals who accept most of the mainstream scientific account of the events believe in a “conspiracy theory” because a group of individuals conspired to bring down the twin towers.

However, this is a fallacy of equivocation as it confuses a conspiracy theory (an unlikely involving shadowy organizations and appeals to pseudoscience) with conspiracy. Conspiracies sometimes do occur, but they are often radically different from those imagined by conspiracy theories. Accepting the existence of real conspiracies, such as the ones involving 9/11 hijackers and the Nazis, are not the promotion of a conspiracy theories in the sense being used here.

Abusing the historiographical intentionalist/functionalist debate

The intentionalist/functionalist debate is an internal debate among Holocaust historians about some of the minor details of the Holocaust, such the involvement of the German bureaucracy. Both intentionalists and functionalists fully accept the three key aspects of the Holocaust listed above. However, this legitimate historiographical debate is exploited by Holocaust deniers. They tend to quote functionalist historians like Arno Mayer out of context in an attempt to attack Holocaust history in its entirety.

This more or less mirrors the way creationists abuse the internal scientific debate between phyletic gradualists and punctuated equilibrium. This scientific debate is about details of the processes of speciation and not about the validity of common descent or the field of evolutionary biology as a whole. Many creationists attempt to abuse the writings and arguments of proponents of punctuated equilibrium (such as Stephen J. Gould) in a misguided attack evolutionary biology as a whole.

The swimming pool at Auschwitz: water reservoir for firefighting and pool for SS men and privileged prisoners

Holocaust deniers use the existence of a swimming pool to argue against the mainstream historical position that Auschwitz was an extermination camp. Here is how Holocaust historian Robert Jan van Pelt explain it (2000):

They ignore that the swimming pool was built as a water reservoir for the purpose of firefighting (there were no hydrants in the camp), that the diving boards were added later, and that the pool was only accessible to SS men and certain privileged Aryan prisoners employed as inmate-funcionaries in the camp. The presence of the swimming pool does not say anything about the conditions for Jewish inmates in Auschwitz, and does not challenge the existence of an extermination program with its proper facilities in Auschwitz II.

This is one of the many cases were Holocaust deniers attempt to distort historical facts to prop up their own pseudoscientific and pseudohistorical belief system.

Zyklon-B was used to murder humans

The amount of Zyklon-B delivered to Auschwitz far exceeds the amount that would be required for delousing. During the Irving v. Lipstadt trial, the Holocaust historian van Pelt made detailed calculations showing that the quantities of Zyklon-B delivered to Auschwitz had around 3-6 times more to kill the estimated quarter of a million people during 1943 left over after delousing (Van Pelt, 2012).

As Irving had raised the issue of Zyklon-B deliveries, I thought that it would be good to study the matter further. Using data that had emerged in the War Crimes Trial of the distributors of Zyklon B – Dr. Bruno Tesch, Karl Weinbacher and Dr. Joachim Drosihn who had run the pest-control company Tesch und Stabenow (TeSta) – held from March 1 to March 8, 1946 at Hamburg, it was clear that in 1942 TeSta had supplied a total of 9,131.6 kg Zyklon B to various concentration camps. Of this amount, 7,500 kg (or 82% of all Zyklon B supplied to the camps) went to Auschwitz. In 1943, TeSta supplied 18,302.9 kg to the camps. Again Auschwitz was the largest recipient, with 12,000 kg Zyklon-B (or 65%).

Taking these and other figures that emerged in the TeSta trial as my basis, I made a whole series of detailed calculations, concentrating on 1943 as that year typhus in Auschwitz was very much under control. My conclusion was that of the 12,000 kg Zyklon B delivered to Auschwitz in that year, a maximum 9,000 kg could have been used for “ordinary” delousing procedures (2,730 kg would have been used for the delousing of clothing, blankets, and other items in use by the prisoners, while some 6,270 kg could have been used for the delousing of barracks). This would mean that all the rest of the Zyklon-B shipped to Auschwitz in 1943 (3,000 kg) would have been available for purposes above and beyond those engaged in other camps such as Sachsenhausen. I calculated that 400 kg of Zyklon-B would have been used for the delousing of the clothing of the deportees in the delousing chamber in Canada I, before shipment to the Volksdeutsche Mittelstelle (VoMi) for redistribution amongst the ethnic Germans. I also calculated that a maximum of 940 kg could have been used for the occasional delousing of the railway freight carriages before their dispatch back to origin. I concluded that at least 1,660 kg Zyklon B was unaccounted for, and I asked the obvious question how many people could be killed by such an amount? The German Health Institution of the Protectorate Bohemia and Moravia in Prague calculated that 70 mg of Zyklon-B suffices to kill one person. 117 This would have meant that, in theory, the surplus of 1,660 kg Zyklon B, if used with 100% efficiency, could have killed (1,660 x 14,000 =) 23.2 million people. But, of course, the efficiency was much lower. Pery Broad testified that the SS used two 1 kg tins to kill 2,000 people., or 1 kg per 1000 people – a ratio of 1 kg per 1,000 people that was also used by Gerstein when he assumed that 8,500 kg of Zyklon B sufficed to kill eight million people. This implies that the 1,660 kg Zyklon-B could have killed 1.6 million people. Testifying in Hamburg, Dr. Bendel stated that 1 kg tin was good for the murder of 500 people, which would mean that 1,660 kg Zyklon B would have allowed for the murder of 800,000 people. I concluded that Auschwitz had a surplus of Zyklon B of between 3 to 6 times necessary to kill the 250,000 people murdered in Auschwitz in 1943.

In other words, the claim that Zyklon-B quantities are consistent with only using it for delousing is wrong.

The claims in the Leuchter report have been debunked

The Leuchter report is a pseudoscientific report on the gas chambers and crematoria of Auschwitz that Holocaust deniers frequently appeal to. However, this has been debunked several times before due to the many methodological flaws. Here are just a facts about the report (McVay, 1998):

(1) Insects are more resistant to hydrogen cyanide than humans, so it is expected to find more Prussian blue in the delousing chambers than in the homicidal gas chambers. In other words, the results of the Leuchter report corroborates the mainstream historical account and not the beliefs of the Holocaust deniers. Furthermore, the homicidal gas chambers has been exposed to the elements in a way that most delousing chambers did not.

(2) Hydrogen cyanide is explosive at high concentrations (~56 000 ppm), but this is nowhere near the concentrations used to kill humans (~ 300 ppm lethal dose, exposure in the homicidal gas chambers on the order of around ~1000 ppm). Thus, they claim that Zyklon-B could not have been used because of the explosion risk is refuted.

(3) diesel fumes contain carbon monoxide which can kill people. The oxygen is rapidly consumed by the victims in the homicidal gas chambers, making the ratio between carbon monoxide and oxygen to increase. Hemoglobin preferentially bind carbon monoxide over oxygen, thereby reducing the oxygen-carrying capacity of hemoglobin. This basic knowledge of biochemistry refutes the claim that diesel fumes (used at e. g. Treblinka) cannot kill humans.

These are just a few of the problems with the Leuchter report. A complete refutation can be found at the Nizkor website.

Multiple, independent eyewitness accounts supported by physical evidence are reliable

Holocaust deniers often attempt to discuss research findings on human memory and the reliability of eyewitness accounts to rationalize up their rejection of the entire class of eyewitness evidence for the Holocaust. While it is true that a single eyewitness might be unreliable, multiple independent eyewitness accounts corroborated by physical evidence are very reliable. By failing to make this key distinction, Holocaust deniers are abusing and distorting cognitive psychology.

Demographics are robust

Holocaust deniers contradict themselves when they simultaneously claim “demographics are unreliable” and that they know with certainty that the number of Jews that were murdered during the Holocaust.

As it turns out, demographics are robust: several different censuses together with several different estimates from historians on the number of Jewish deaths independently converge on around 6 million (Shermer and Groban, 2008, pp. 174-178). Holocaust deniers typically attempt to rationalize each single estimate by pointing out some of their limitations. However, this is not sufficient, as the independent converge on different lines of evidence with regards to the number of Jewish deaths is a strong piece of evidence. It is very unlikely that independent lines of evidence would converge like this if the conclusion was radically wrong. Compare this with radiometric dating: some methods have limitations, but the fact that different methods converge on the same dating intervals is powerful evidence for an old earth.

The Ausrotten gambit declined

In many speeches and texts produced by Nazis at the time of the Holocaust, the word “ausrotten” appear in association with e. g. the Jews and this word means extermination. This is an awkward fact for Holocaust deniers, who attempt to rationalize this by arguing that ausrotten really just meant uprooting and that the Nazis just wanted to deport the Jews. However, the “ausrotten” of the Jews is used in the same documents and speeches as the “ausrotten” of “bacillus” and “tuberculosis” (Holocaust History Project, 2004; Shermer and Groban, 2008, pp. 205-208). Surely, no serious person can believe that the Nazis wanted to round up tuberculosis bacteria, put them on trains and deport them out of the Third Reich.

Bonus round: Holocaust deniers attempt to “respond”

A previous post I wrote about the problems with Holocaust denial was posted on a forum for Holocaust deniers. Although I will not link it out of principle, it can easily be found with a Google search. Here are some of the highlights:

Name-calling: throughout the forum topic, I am refereed to as a “believer”, “woefully misinformed”, “belligerent towards free speech” and a “Marxist-Statist” (whatever that means). According to their own forum rules, name-calling is not allowed.

Misunderstanding of the cognitive psychology of memory: They also contradict themselves and call me a “revisionist” because I have pointed out the problems with single eyewitness accounts in a previous post. However, as was explained above, this is very different from multiple, independent eyewitness accounts backed by physical evidence. Contrary to the claims of the Holocaust deniers, I did not shoot myself in the foot.

Accusations of straw man fallacies: some of the Holocaust deniers at that forum accuse me of making a straw man argument because they have not heard any Holocaust denier making some of the claims that the denier that I refuted did. However, this is a peculiar argument as I was addressing the argument that this particular denier made and never claimed that Holocaust deniers as a whole hold that belief.

False balance: one Holocaust denier on that forum seems upset that I only list references and further reading from the Holocaust historian “side”. However, there are not two sides to the Holocaust, just like there are not two sides to evolution, climate change, HIV and so on. This is a classic denialist tactic called false balance. The texts that I referenced were either the ones that I originally read and learned about the problems with Holocaust denial or general information texts that could be interesting for those wanting to learn more about this pseudohistorical movement. Including books by Holocaust deniers would make just as little sense as listing books written by cancer quacks when talking about the molecular biology of cancer.

Complains about comment moderation: two Holocaust deniers decided to post some comments on the previous entry. Because this blog is not intended as a platform for Holocaust deniers, I decided to decline publication of those comments (I addressed most of their claims in this blog posts). I am sure that some Holocaust deniers will start whining about “free speech”, but they should know that I accept a Rothbardian conception of free speech in this context: you are welcome to spout whatever nonsense you want on your blog or on other websites that agree to it, but this is my blog. I therefore have the right to decline publication of comments if I think it is justified. Calling me a “Marxist” is therefore quite ironic.

“Debate” challenge: Two poster expressed a desire for me to go over to their forum and debate them. However, this is unlikely to be productive for a number of reasons: (1) entrenched denialists are very difficult to convince, (2) since it is a Holocaust denial forum, it is unlikely that many fence-sitters will read it, (3) I do not trust these individuals to protect my registration data and (4) their forum rules demand that posts are limited to one point and forbid lengthy posts (which are incompatible with such a “debate”).

Anomaly hunting: like 9/11 truthers, the Holocaust deniers in that thread spent a lot of time posting alleged anomalies concerning small details that they do not think can be explained. However, many of them can be explained (I treated many of them earlier in this blog post) and even if the current historical research has not focused sufficiently on them to provide a satisfactory answer, the anomalies often regard minor details and do not have the implications that many Holocaust deniers think.


Drawing moral equivalences are problematic as the existence of other horrible crimes do not negate the crimes of the Nazis. Holocaust revisionists are actually Holocaust deniers as they reject many of the core aspects of the mainstream historiography of the Holocaust. Like creationists abuse the internal scientific debate between phyletic gradualism and punctuated equilibrium as if it was a debate about the validity of common descent, Holocaust deniers abuse the internal historical debate between intentionalists and functionalists in an attempt to spread uncertainty and doubt regarding Holocaust history at large by quoting historians out of context.

The swimming pool at Auschwitz was a water reservoir for firefighting and pool for SS men and privileged prisoners. The surplus of Zyklon-B left over after delousing at Auschwitz was around 3-6 times more to kill the estimated quarter of a million people during 1943. The claims of the pseudoscientific Leuchter report has been disproved: in reality, the concentration of hydrogen cyanide was too low to be explosive, diesel fumes contain carbon monoxide which can kill people, lice are more resistant to hydrogen cyanide than humans and the walls of the homicidal gas chambers has been exposed to the elements for many decades.

While a single eyewitness might be unreliable, multiple independent eyewitness accounts corroborated by physical evidence are very reliable. By failing to make this key distinction, Holocaust deniers are abusing and distorting cognitive psychology. Demographics and estimates of the number of people killed independently converge, making demographics estimates robust. The word “ausrotten” means exterminate when applied to living things, and no amount of rationalizations by Holocaust deniers will change this was some Nazis spoke of “ausrotten” bacillus or tuberculosis in the same speech and document as “ausrotten” the Jews. No serious person can claim that the Nazis wanted to put tuberculosis bacteria on trains and deport them out of the country.

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References and further reading:

Holocaust History Project (2004). ‘Ausrotten’ in Translation: Holocaust-Denial, the Poznan speech, and our translation.. Accessed: 2013-09-14.

McVay, K. N. (1998). Holocaust FAQ: The Leuchter Report. Accessed: 2013-09-14.

Shermer, M & Groban, A. (2008). Denying History: Who Says the Holocaust Never Happened and Why Do They Say It? Berkeley and Los Angeles, California: California University Press.

Van Pelt, R. J. (2000). The Van Pelt Report. Accessed: 2013-09-14.

Van Pelt, R. J. (2012). Re: P. The quantity of Zyklon-B required. Accessed: 2013-09-14.