What is "reductio ad hitlerum"

n. The conclusion that the fact that (w: Adolf Hitler) had a particular idea or quality is sufficient proof that the idea is wrong or the property is bad.

Reductio ad Hitlerum, also argumentum ad Hitlerum ( Latin for "reduction to Hitler", where Hitlerum serves as the accusative case of Adolf Hitler's surname in Latin) is a term coined by German-American philosopher Leo Strauss in 1951. According to Strauss, the Reductio ad Hitlerum is a humorous observation where someone compares an opponent's views with those that would be held by Hitler or the Nazi Party.

According to Strauss, Reductio ad Hitlerum is a form of ad hominem, ad misericordiam, or a fallacy of irrelevance. The suggested rationale is one of guilt by association. The term is coined in an analogy with " reductio ad absurdum".

Reductio ad Hitlerum is sometimes called "playing the Nazi card". According to its critics and proponents, it is a tactic often used to derail arguments, because such comparisons tend to distract and anger the opponent, as Hitler and Nazism have been condemned in the modern world.