Reductio ad Hitlerum

Reductio ad Hitlerum, also argumentum ad Hitlerum, or reductio (or argumentum) ad Nazium – Dog Latin for "reduction (or argument) to Hitler (or the Nazis)" – is a modern sub-type of fallacy in logic. It is a variety of both questionable cause and association fallacy. The phrase reductio ad Hitlerum was coined by an academic ethicist, Leo Strauss, in 1950.

The fallacy assumes the form of "Hitler (or the Nazi party) supported X, therefore X must be evil/undesirable/bad"; or, less commonly, "Adolf Hitler was against X, therefore X must be good/desirable/praiseworthy". This fallacy carries emotional weight as rhetoric, since in many cultures anything to do with Hitler or Nazis is automatically condemned.

Fallacious nature of the argument

Reductio ad Hitlerum is rationally unsound for two different reasons: As a wrong direction fallacy (a type of questionable cause), it inverts the cause–effect relationship between why a villain and an idea might be criticized; conversely, as guilt by association (a form of association fallacy), it illogically attempts to shift culpability from a villain to an idea regardless of who is espousing it and why.

Those policies advocated by Hitler and his party which are generally considered evil are all condemned in and of themselves, not because Hitler supported them. In other words, genocide and white supremacism, as two examples, are considered evil on their own basis, while Hitler is considered evil for numerous reasons largely because he advocated them. A common example of the fallacy in action is, "The Nazis favored eugenics, therefore eugenics is wrong." But the ethical debate over eugenics really has nothing to do with Hitler or the Nazis in particular; both eugenics and criticism of it considerably predate Nazism, and have gone well beyond it, into concerns about modern genetic engineering, unknown to Hitler. Used overbroadly enough, ad Hitlerum can even span the boundaries of more than one questionable cause fallacy type, as it does in the eugenics example, by not only inverting cause and effect but by linking an alleged cause to things that are wholly unrelated.

Ad Hitlerum can also be combined with ad hominem or personally-attacking arguments. Reasoning such as "you are wrong because Hitler said something similar, and Hitler was evil, so you must be evil too" is doubly fallacious, and as such is also related to the fallacy of appeal to emotion.

The argument being fallacious, however, does not prove X, or its supporters, not being evil (assuming so would be another fallacy, namely affirming the consequent). Moreover, recall that the argument is fallacious in itself, no matter whether X is actually good or evil. So, "Hitler killed human beings, therefore killing is wrong", is nonetheless a fallacy, however truthful the premise and conclusion may be, because there is no logical connection between the two. It would be akin to "I wear trousers, therefore tomorrow it will rain". This sentence is logically faulty, even if the speaker does wear trousers, and the next day does turn out rainy.

Various criminals, controversial religious and political figures, or tyrants other than Hitler could be used for the same purposes. For example, a reductio ad Stalinum could assert that corporal punishment of wayward children is necessary because Josef Stalin enacted its abolition, or that atheism is a dangerous philosophy because Stalin was an atheist. Similarly, a reductio ad Cromwellium would equate enjoying chamber music with hating the Irish. Such constructions, as a class, make no more sense than saying moustaches are evil because Hitler and Stalin had moustaches.

Countering the fallacy

The fallacious nature of reductio ad Hitlerum is, however, most easily illustrated by identifying X as something that Adolf Hitler or his supporters did promote but which is not considered unethical, such as watercolor painting, owning dogs, or vegetarianism. It may be refuted through counterexamples using figures with reputations generally opposite that of Hitler:

• Prime Minister Sir Winston Churchill, Hitler's British opponent, also painted.
• President Franklin Delano Roosevelt and his successor Harry Truman, Hitler's American opponents, also owned dogs.
• India's reformer Mahatma Gandhi was also a vegetarian.

The fallacy is common enough that the counter-example is often used without a proper explanation. Dismissively saying, "yeah, and the Nazis made the trains run on time", and expecting the listener to understand the reference to reductio ad Hitlerum.

History

The phrase reductio ad Hitlerum is first known to have appeared in University of Chicago professor Leo Strauss's 1950 book, Natural Right and History, Chapter II:

In following this movement towards its end we shall inevitably reach a point beyond which the scene is darkened by the shadow of Hitler. Unfortunately, it does not go without saying that in our examination we must avoid the fallacy that in the last decades has frequently been used as a substitute for the reductio ad absurdum: the reductio ad Hitlerum. A view is not refuted by the fact that it happens to have been shared by Hitler.

The phrase was derived from the better known (and sometimes valid) logical argument called reductio ad absurdum. The argumentum variant takes its form from the names of many classic fallacies, such as argumentum ad hominem.

In popular culture

The relative frequency of such comparisons in Usenet discussions led to the formulation of an adage called Godwin's Law in 1990, which posits that analogies involving Hitler or the Nazis become increasingly likely the longer an online discussion takes place.

At least the concept behind reductio ad Hitlerum sometimes makes appearances in the mass media. For example, in a Dilbert cartoon (Published 28th Oct. 2006) the character Ratbert says that he is winning all his debates on the Internet by asking, "How would you like it if Hitler killed you?"

See also

• Godwin's Law
• List of fallacies
• Wisdom of repugnance

References

• Logical Fallacy: The Hitler Card