"It would be wrong for our country to spend a lot of money on highways this year. After all, Hitler spent a lot on the Autobahn." I gather this 'argument' can be stated formally this way: Hitler pursued aggressive wars and genocide. Hitler built a highway. Therefore, building a highway is tantamount to aggressive wars and genocide. Am I right in naming the formal fallacy there, as above.
Anonymous
Fallacy.
Like saying the world is in trouble because an Orangeman is in office, totally ignoring the actions of Congress, and Civil Servants.
"Blame it on Herr Hitler, he is a bad guy, he was in office when the war was lost."
Herr Hitler was also a Vegan, and into Horoscopes,
Herr Hitler was popular in the beginning, because he promoted what the People Wanted.
Anonymous
Not really - it is certainly a fallacy. The terms have nothing absolute in common: the first deals with right and wrong, but the second makes no real reference except by implication. This seems to be an affirmative conclusion from a negative premise, but adding Hitler into the mix implies it must be a bad thing.
Building the autobahns was actually a way of reducing unemployment (a good thing). (Paying for them was not sustainable - but that didn't matter as Hitler would be plundering the gold reserves of several European countries) but as far as the country was concerned it was a good thing if you consider building a Reich was a positive, and enabled rapid troop movements between its borders (its orignal purpose).
Jeff D
It can be, depending how it's used. Reworking your example a bit:
1) Hitler built the Autobahn (All Z is B)
2) Eisenhower built the US Interstate highways (All Y is B)
3) Therefore, Eisenhower is just like Hitler (Therefore, Y is Z)
More generally, the reductio ad Hitlerum argument is a form of ad hominem, ad misericordiam, or a fallacy of irrelevance. The suggested rationale is often one of guilt by association.