I forgot about this part of your comment, and it's important: > We need to understand what caused those mistakes, but even more important we need clear and pra

I forgot about this part of your comment, and it's important: > We need to understand what caused those mistakes, but even more important we need clear and practical rules about how to avoid that entire class of mistakes, including future similar mistakes that we have not made yet Fully agreed! I think it's worth debating what led Hitler down this path, and how he could convince people of its righteousness. To be clear, I'm not arguing against debating this. It's important, like you said, to get rid of whole classes of colossal mistakes (another example would be: "in order to prevent genocide, we need to commit genocide first!" -- the root problem is still genocide). Understanding dictators, torturers, flawed political systems is always important and valid. What I'm arguing, plain and simple, is that whenever anyone decides genocide is the solution, that is in itself a moral failure and a horrific mistake, regardless of any other considerations. There may be other mistakes (like waging war against the Soviet Union, or failing to consider the industrial might of the USA, or even failing to understand the logistics of protracted war), but even without those mistakes, genocide was still an a priori moral failure.