What is reductio ad Hitlerum?
According to Wikipedia, reductio ad Hitlerum, Latin for “reduction to Hitler,” is a term coined by German-American philosopher Leo Strauss in 1951. The idea is that in an argument, people invoke Hitler or Nazis to prove their point.
According to fallacyfiles.org, one example is this:
Hitler was in favor of eugenics.
Therefore, eugenics is wrong.
However, here is a counter-example:
Hitler was a vegetarian.
Therefore, vegetarianism is wrong.
(Video by John Green)