It was Thomas Paine who said it was only the absence of knowledge that could keep a man ignorant; but while he maybe kept ignorant he cannot be MADE ignorant. Therefore free society should recognise people as rational beings and leave them to discover the truth by their own devices. Incidentally, most arguments for totalitarianism start with the opposite view: people need protecting from "dangerous" ideas.
The truth will out. You can't fool all the people all the time. Etc.
It's not about protection from dangerous ideas, it's about arming the populace with the tools to more readily determine for themselves which ideas are dangerous, and to protect themselves.
And the thing is, you don't really need to fool all the people, just most. Unfortunately, it seems that willful ignorance is the norm in many areas, and while I agree that reality has a tendency to win out in the long term, it can do a lot of damage in the short term.
What you're saying sounds good and is one of the reasons for the creation of public schools. But it also creates an opening for government indoctrination.
Then there's the opposite problem, privatized indoctrination where billionaires like News Corp's Murdoch get to influence millions with his propaganda.
Then the internet was supposed to save us but it turns out people like living in their own indoctrination bubbles and the internet is more than happy to provide it for them.
Starting out by teaching them to recognize indoctrination would be a good step, then. That's a fairly core part of critical thinking anyway, recognizing bias in the speaker.
Therefore free society should recognise people as rational beings
and leave them to discover the truth by their own devices.
Unfortunately, societies are not perfect systems and as can be seen, people can be influenced; not because of anything other than laziness. Majority outsource decision making to others and can easily display herd mentality. I agree that critical thinking and education is the most useful tools against ignorance but I don't know of a fix for laziness.
The truth will out. You can't fool all the people all the time. Etc.