> there's already a well defined level that Popper, common law, and the US constitution have all given The "utterance of intolerant philosophies" does not sole

> there's already a well defined level that Popper, common law, and the US constitution have all given The "utterance of intolerant philosophies" does not solely refer to calls for violence or assault. As you point out yourself, that sort of speech had long been covered by the "harm principle" in common law and would have been entirely superfluous for Popper to rehash in the 1940s. In this and other writings he was clearly outlining a new class of speech and proposing a restriction on it. > it's not this nebulous idea of anything that gives rise to something bad That is also not what Popper described. There are clearly many things that give rise to something bad yet would not qualify as "intolerant philosophies" because their adherents are willing to conduct a rational argument and unlikely to resort to violence. Of course people are free to reject Popper's argument and embrace the lesser constraint of the harm principle so that they can do things like debate Nazis on the internet. Personally I think there are some compelling arguments in favor of erring on the side of free speech. But we should be honest that this involves rejecting Popper's argument, not stretching it to mean whatever we want. > Those who are looking to suppress that are on the same level as Nazis and reveal their lack of confidence in their own ability to counter criticism of their position - just as a Nazi might - and hence, reach for violence. I do not understand this. Are you saying Twitter moderating Nazis is a form of violence?