The progress of science wasn't driven by nutjobs delivering spittle-flecked rants on Youtube. Almost all of it was driven by careful peer review of ideas -- which is the exact opposite of unrestricted speech.
https://blogs.scientificamerican.com/information-culture/the... has some indications that peer reviewers generally don't do a great job.
Not everybody is a traditional upperclass gentleman and not everybody who isn't is wrong.
First you show the world you exist and convince your friends it's worth trying to change things, then you convince the moderates, then you win the fight, then you wait for your bitter enemies to die because they'll never be convinced but at least their kids are open to new ideas.
Pissing off your bitter enemies can be hard to avoid and still get the job done.
And the parades are still full of weirdos, but they won, so now it's okay.
Please, explain: how do queer ideas harm society, in the longer run?
His contemporaries were not particularly impressed, but he probably wouldn't have been censored, if he also didn't try his damned hardest to personally piss off everyone in his social circle.
His 'efforts' probably set the adoption of heliocentrism back by decades.
https://tofspot.blogspot.com/2013/08/the-great-ptolemaic-sma...
I encourage you to review some of the early to mid 20th-century publications on the topic. "Science" backing segregation. Americans pontificating about whether Hitler was right or that blacks should be sterilized, and then actually doing it. Doctors. In hospitals. "Three generations of imbeciles are enough" from the US Supreme Court.
If you think we're in the same state now as we were then, you don't know where we were then.
> I'm not sure how effective a disinfectant sunlight is if it takes centuries to work.
You would prefer the alternative where anything contradicting the then-prevailing doctrine of racial supremacy and eugenics was censored? How long does the truth take to get out in that case? And what happens in the meantime?
Leaded gasoline, phlogiston, cold fusion, phrenology, scientific racism, basically the entire history of the progress of science.
But let's also not forget that you're asking for a list of discredited ideas, so you wouldn't have heard of them, by definition, if things are working as they should, because they're wrong and the former proponents have long since abandoned trying to disseminate them to you.
> Deplatforming these people and, importantly, showing social pressure that these are bad ideas and shouldn't even be entertained as valid debate, has shown to work repeatedly.
If all you're doing is defining "work" as "the censorship target was censored" then you're not claiming anything. When you kick these people off of major platforms, they don't cease to exist, they break off like an extremist splinter group and go to a place with no moderating influences to fester. You don't see them anymore, but they're still there, and then suddenly somehow Donald Trump is the President of the United States and people can't believe it and don't understand how it happened.
> In fact, social pressure is one of the most effective tools against hate and ignorance like this.
Censorship isn't social pressure, it's force. Social pressure is telling wrong people why they're wrong, every time.
People who are wrong need to be made right, not made frustrated and angry and yet not only still wrong but now even more convinced that their wrong ideas are right because they now have real evidence that they're not getting a fair public debate.