In Nazi analogies are situations compared to those of the Nazi regime. Often such comparisons are met with heavy opposition. Three types of such opposition have become well known.
The first of the well known types of opposition against Nazi analogies regards the 'reductio ad Hitlerum' as explicated by the Jewish political philosopher Leo Strauss (1899-1973). He first explicated this term in 19511 and explained it further in 1953.2 The term 'reductio ad Hitlerum' was derived from 'reductio ad absurdum'. The latter regards an argument for the truth of a statement by showing the absurdity of what is reduced from its denial.3 That hairs don't have nerves because otherwise cutting them would hurt is such an argument. Literally can 'reductio ad absurdum' be translated as 'reduction to absurdity'.4 'Reductio ad Hitlerum' then can be translated as 'reduction to Hitler'. And this regards an argument that refutes an assumption on base of it being found with Hitler or the Nazi's as well.5 The ideal of the overman or superman (or 'Übermensch' in German)6 is for instance often refuted by pointing it out as an ideal in Nazi Germany. The point that Strauss wanted to make with his 'reductio ad Hitlerum' term was that "a view is not refuted by the fact that it happens to have been shared by Hitler".7 For that could lead to the absurd conclusion for instance that because Hitler was evil and was wearing a mustache all mustache wearing men should be considered as evil. It is thus correct when this type of Nazi analogy is opposed.
The second of the well known types of opposition against Nazi analogies regards 'Godwin's law' as explicated by the author Michael Wayne 'Mike' Godwin (1956). The law was defined by Godwin on the internet in 1990 as follows: "As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one."8 This sounds reasonably and very descriptively but it was actually meant normatively opposed to Nazi comparisons.9 Godwin found Nazi comparisons both illogical and offensive.10 He found them illogical because those that were compared to Nazi's were themselves obviously no Nazi's. Here it seems that Godwin failed to make a clear distinction between a comparison and an equation. He is refuting Nazi comparisons with the logic of equation. It is indeed illogical to equate for instance the American politician Michael Dukakis with Adolf Hitler, however it is not illogical to compare him with Adolf Hitler. The formula d=h (Dukakis is Hitler) is apriori untrue, however the formula Hh∧Hd (Hitler has Hitler qualities and Dukakis has Hitler qualities) is not apriori untrue and can only be found to be untrue a posteriori. The latter formula needs further analysis for the determination of its truth value and cannot be discarded at forehand. Such a formula can only be discarded at forehand when it is posited that no quality that is found with Hitler can be found with someone else. And this cannot be truthfully posited because that would mean that for instance Hitler would have been the one and only mustache wearing person.
As above shown it can easily be refuted that Nazi analogies or comparisons are illogical. They are logically no less coherent than any other analogy. However Godwin also feels that such analogies are offensive. This third well known type of opposition against Nazi analogies is backed heavily by Jews in general. It must be set clear that in this type of opposition the ones that are considered as being offended are not those that are compared to Nazi's but the Jews in general. It is considered as offensive for Jews because a comparison deprives them from having a unique position of suffering. Their suffering is considered as being so unique that nobody else can suffer as they did. Now without trivializing the immense damage that was inflicted to the Jews by the Nazi's it is again not logical to isolate the quality of immense suffering as the Jewish suffering under the Nazi regime. The Jews suffered immensely but others can suffer immensely too. So on a logical level there is no reason to avoid using Nazi analogies. On the level of emotion however there may be a reason. For the upsetting of other's emotions should be avoided when possible. Nevertheless are feelings of a subordinate nature where reasonability is in play. Sometimes it may be reasonable to use Nazi analogies despite aroused emotions of others. The offence taken by use of Nazi analogies should after all not become an emotional blackmail for the preservation of a unique position of suffering.
So when then is it reasonable to use Nazi analogies? First it must be mentioned that Nazi analogies can have their purpose. In general do comparisons and analogies bare certain inner structures of situations. With this they may enhance the accuracy of interpolation and inference. When for instance the example of Hitler is taken as having the same color hair as his eyebrows and mustache then the example may serve by analogy to infer for a person with a blonde mustache and blonde eyebrows to have also blonde hair. As such can Nazi analogies be just as useful as any other analogy. In fact may Nazi analogies even serve as important warnings for contemporary situations. Every year do many countries which were involved in the Second World War remember its victims, stating that such a horror must never occur again. Now if such a situation must never occur again it is very important to learn from that terrible past. And this means beholding the structures that were present in Nazi Germany and being able to recognize similar structures when they are taking form in contemporary situations. So Nazi analogies may serve to safeguard us from making the mistakes that were made by the Nazi's. And this is basically the touchstone of the reasonable use of Nazi analogies. Where they don't serve as a heed of warning and as a safeguard the emotions of others should be spared by leaving them aside. Where situations and people however tend to form structures that resemble the typical structures of the Nazi's then the bringing to the fore of Nazi analogies is in place and even advised.