Eugenics... A Must Watch?

I really don't know enough about it other then the Nazis believed whole heartedly in what was then a worldwide scientific consensus that it was the truth. After the fascist governments in Europe were defeated, it was discredited. Whether that was politics or science, I don't know. There must have been a reason so many scientists believed it was the truth so there are likely elements of it that were factual but, it is really a taboo subject now so scientists will no longer scrutinize it meaning it will remain refuted and politically incorrect - it will never be proven either true or false as a result.