That's why there are things like laws. I agree that those things are absolutely horrible and have no place in MODERN society, but by your logic, people who believed it in the past should not have either. Its the mistakes of others that we can learn from, and therefore grow as a result. As such, things such as Racism and Nazism had positive impacts on the future, whether or not they were "Right" or "Wrong". You have to see more than one perspective, and accept them all, no matter what you believe is right or wrong. Think of it this way: Who is a better source of information, someone biased in any way (Whether it be towards your own beliefs, or something opposite), or someone who looks at it objectively, ignoring all perspectives and only stating the facts? Obviously, the correct answer is the latter. Of course, actual objectiveness is a lie. There is no way possible for a human being to be objective. The only way we come anywhere near close is by looking at everything, and accepting it, no matter how bad we think it is. Why did the nazis kill Jews? Because they were afraid of them. We attack what we fear, and that is only human. I never once said that I condone those actions, but we would not be where we are as a species had it not happened. Things would most likely be worse, because the mistake would not have been made for us to learn from. Im not saying you should change your beliefs, and Im not saying they are wrong, Im saying that it is incorrect to discount the beliefs of others due to your own. Only by combining our beliefs can we achieve more than we could ever do alone. There is no single version of the truth, that's just how life works.