reductio ad hitlerum

Reductio ad Hitlerum

and

Godwin's Law (the first to mention Hitler in an argument automatically looses)

http://en.wikipedia.org/wiki/Reductio_ad_Hitlerum

(dog Latin for "reduction or argument to Adolf Hitler or the Nazis") is an ad hominem or ad misericordiam argument, and is a fallacy in logic. The name is a pun on reductio ad absurdum. The phrase reductio ad Hitlerum was coined by an academic ethicist, Leo Strauss, in 1953. Engaging in this fallacy is sometimes known as playing the Nazi card,[1] by analogy to playing the race card.

It is a fallacy of irrelevance where a conclusion is suggested based solely on something or someone's origin rather than its current meaning or context. This overlooks any difference to be found in the present situation, typically transferring the positive or negative esteem from the earlier context. Hence this fallacy fails to examine the claim on its merit.

The fallacy most often assumes the form of "Hitler (or the Nazis) supported X, therefore X must be evil/undesirable/bad,"[1]. For example: "Hitler was a vegetarian, so vegetarianism is wrong." The tactic is often used to derail arguments, as such a comparison tends to distract and to result in angry and less reasoned responses.

The widespread use of this fallacy on internet message boards led to the creation of "Godwin's Law"- a humorous adage that as the length of an online discussion increases, the probability of a comparison involving Nazis/Hitler approaches one. Hitler/Nazi comparisons received widespread mainstream media attention in 2009 during debate on health care reform in the United States, due to comments from citizens attending town hall forums as well as radio and television commentators.