But when it comes to many of the "revolutionary" ideas being spread today, we already have hindsight.
The "revolutionary" ideas that black people are categorically less intelligent than whites, and that therefore Africans would be incapable of civilization were it not for the effects of slavery and colonialism, that the only reason African Americans are disproportionately targeted by police is their genetically innate propensity for crime and violence, that multiculturalism and miscegenation are inherently harmful and a threat to white civilization, and maybe segregation and ghettos weren't a bad idea after all?
We've been there. We've considered that. We've had the debates, the civil war, the riots. We've realized that's a terrible idea. Most of us, anyway.
What about the "revolutionary" idea that the Enlightment was a disaster, and that democracy and egalitarianism should be abandoned in favor of a return to absolute monarchy, eugenics and neo-fascism?
We've been there. We've considered that. We fought wars to claw our way out of the divine right of kings and the brutal hand of dictatorship because we realized that it's a terrible idea.
Ok, what about the "revolutionary" idea that the earth is flat?
We realized that was a terrible idea before we learned to smelt iron. Ok, true, most people don't bother doing the experiments necessary to prove the Earth is round, and tend to take it on faith. But that's not because people are blind and ignorant sheep being led astray by the military scientific complex, it's because it's trivially obvious.
The Jewish Question?
That certainly had its time in the marketplace of ideas to say the least.
We don't need to keep QAnon's dialogue alive just in case it turns out in hindsight that the Democratic party really is a cult of satanic pedophiles who drink the blood of child sex-slaves to extend their lives after all, nor do we need to deeply and soberly consider the possibility that COVID-19 really is a globalist population control experiment manufactured by Bill Gates as a pretext to implanting everyone with mind control chips, nor do we need to "teach the controversy" around creationism just in case it turns out God planted dinosaur fossils just to test our faith.
Sometimes, despite attempts to obfuscate the fact, we do know which ideas are terrible.