While observing and participating in many early online discussions, my friend Mike Godwin in 1990 created “Godwin’s Law,” which states:
As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches 1.
The concept of Reductio Ad Hitlerum applies to offline discussions as well. This political season, both major parties and their affiliated PACs (political attack committees) have been accused of “The Big Lie,” a principle first described by, yes, Adolph Hitler. In Mein Kampf, Hitler wrote that:
. . . in the big lie there is always a certain force of credibility; because the broad masses of a nation are always more easily corrupted in the deeper strata of their emotional nature than consciously or voluntarily; and thus in the primitive simplicity of their minds they more readily fall victims to the big lie than the small lie, since they themselves often tell small lies in little matters but would be ashamed to resort to large-scale falsehoods. It would never come into their heads to fabricate colossal untruths, and they would not believe that others could have the impudence to distort the truth so infamously. Even though the facts which prove this to be so may be brought clearly to their minds, they will still doubt and waver and will continue to think that there may be some other explanation. For the grossly impudent lie always leaves traces behind it, even after it has been nailed down, a fact which is known to all expert liars in this world and to all who conspire together in the art of lying.
(Hitler was employing the logic of Reductio Ad Judaeus; in any prolonged discussion by anti-Semites, the probability of blaming everything on the Jews approaches 1.)
Hitler’s propagandist Hermann Goebbels, perhaps believing that Winston Churchill was Jewish, applied the Big Lie to the British:
The essential English leadership secret does not depend on particular intelligence. Rather, it depends on a remarkably stupid thick-headedness. The English follow the principle that when one lies, one should lie big, and stick to it. They keep up their lies, even at the risk of looking ridiculous.