In the context of history, the word "revisionist" has two distinct meanings. The first sense is the perfectly sound academic effort to improve our understanding of history through new evidence or the application of new analytical methods to old evidence. When an error is discovered, a gap filled, or an alternative explanation offered, such revision is beneficial. The second sense, however, is where history is revised due to ideology. "I object to this interpretation of the past, and I choose to reinterpret it through my biased lens while discarding any evidence that contradicts me," says the dishonest revisionist.
Let's illustrate this by jumping straight into Godwin's Law territory by considering Nazi Germany under Adolf Hitler, because if I'm going to discuss something controversial, why not dive right in to the nastiest controversies possible and be done with it?
Suppose, just for the sake of argument, that a "mere" 600,000 (rather than the commonly reported number of 6,000,000) Jews were butchered under Hitler's regime. Does that mean the operation was less evil somehow, and Nazis are proportionately increased in virtue by this? No. Now suppose that in reality, 600,000 Jews were murdered. Does inflating the number tenfold to 6 million make Nazis more evil? No. The ideology is the same in either case. People were murdered en masse by adherents to that ideology in either case. So Nazi revisionism could be an honest attempt to examine the records from a neutral perspective of accuracy, a futile effort to clean up the Nazi legacy as though it can be made presentable, or an attempt to magnify their crimes as though they aren't evil enough.
Now, let us consider another question. How many people were killed for belonging to a non-Jewish but still "inferior" race or group? Slavs, Gypsies, political dissidents, homosexuals, communists, free market advocates, the mentally ill, and other "undesirables" were also swept up in the Nazi machine to be robbed, caged, and/or killed. These are often forgotten in the common narratives about Nazi Germany and World War 2. This is also revisionism through oversimplification and omission. Is this honest historical analysis?
Since we don't have time travel, and sifting through historical records is a highly specialized skill requiring a lot of dedication, we must balance skepticism with trust in the experts in the field of history. We must also be wary of those who claim special knowledge that contradicts a popular narrative. Which is more plausible, a conspiracy by historians, or a crank trying to make a quick buck off a scandal fueled by prejudice?
Oh, right. Both sides will confirm their biases there, and that is the real hurdle of any rational inquiry. Even in the "hard sciences," there is a risk of faulty analysis and bias in the interpretation of empirical evidence like we see in the climate change debate, where the adherents to anthropogenic global warming insist the data supports their case, while those who disagree often argue for the opposite conclusion from the same data. Both sides also argue that the other uses faulty data in their analyses.
Since history doesn't actually repeat itself, we can at times find it even more difficult to discern the truth of matters in this field. One of the things I like about many history podcasts is the openness of the hosts to explore alternate accounts of past events and alternate explanations for why things unfolded as they did. Mike Duncan's History of Rome podcast had frequent episodes where events were offered with multiple possible explanations, or even completely different accounts of the same event, so Mike offered the various alternatives with his own opinions while always trying to clarify what was more speculative and what was more concrete. The Dangerous History Podcast explores the facts of history through a different interpretive lens without distorting the facts themselves.
Before I wrap up, I suppose I need to offer my own thoughts on the concentration camps, since I brought it up as the illustrative example for this phenomenon. I honestly don't know how many Jews were killed. I don't know how many Gentiles were killed either. I have it on good authority that many were in fact killed, and while I don't like to appeal to authority, reliance on experts is not necessarily fallacious. Six million is a mind-bogglingly huge number, but we have seen how dreadfully efficient governments are at what they do best—namely theft and murder—throughout history and current events. Conspiracy theories supporting genetic guilt or racial superiority/inferiority are absurd, and apologists for genetic extermination have no sense of reason or justice.
Setting aside the question of mass murder, fascism itself has no redeeming features either. As Doug Casey wrote in The International Man, 2nd ed. © 1979, p. 77,
Fascism
This term immediately brings to mind images of jack-booted storm troopers, Chicago's late Mayor Daley and militarism. These things are only accidental (albeit usual) political ramifications of the system - which is purely economic in itself. Fascism may be defined as an economic system where although the "means of production" and "consumer goods" are owned by individuals, they are essentially controlled by the state. Hitler's Germany is, of course, the classic example. Krupp, I.G. Farben, Messerschmidt - all were privately owned, but the government told them what to produce, how much to charge, what to pay their laborers, how much profit they might make, and regulated every other aspect of their existence. Just so, are General Motors, Lockheed, Westinghouse and most other U.S. corporations privately owned; but the government dictates maximum prices, quality ("safety") standards, minimum wages and every other detail directly through the various regulatory agencies (CAB, FTC, ICC, OSHA, etc) in addition to profit margins through its monetary, taxing and, increasingly direct "bailout" policies.
There is no difference whatsoever in kind between Nazi Germany's and America's systems; the differences are only in degree and in detail. Scandinavia is another superb example; don't be confused by all the welfare benefits; Hitler's Germany also had a full complement of them.
Militarism, racism, genocide, and other such consequences are probable symptoms of fascism, but not causes or requirements. However, the apologist for fascism will deny every adverse effect of his creed, even to the point of rejecting verifiable historical facts or blaming the victims. In the end, I am OK with assuming that approximately 6 million Jews and over 5 million other "undesirables" were butchered by the Nazi regime over the course of its 12-year reign, but even if there weren't that many, inflating the death count in the Holocaust is not needed to prove the destructiveness and sheer evil of totalitarianism, and minimizing the death toll does not prove that fascism has some kind of merit to excuse its atrocities. Be skeptical of anyone who ever wants to excuse any brand of tyranny, especially when they have to challenge history to do so.