Ancient wisdom often sounds like common sense now that it is commomly taught. What is some ancient wisdom that we no longer teach because it was wrong?
I read Montaigne's essays (written in the 1500's) and while his views are remarkably modern in many ways, one thing that stuck out to me was how unabashedly elitist he is. The translation I had used the phrase "common herd" to refer to the large majority of people who failed to impress him due to their lack of education or strength of character. I hesitate to speak for him since I think he was a wiser man than I am, but I expect that our modern notions about democracy would have seemed ridiculous to him. He might accept that universal suffrage is in practice the least-bad option currently available to us, but he would argue that at least in principle it would be better to exclude people who don't actually know how to run a country from the process of deciding how the country is to be run.
(He would also be unashamed to say that the life of an exceptional person is worth more than the life of someone ordinary, but we think that in the modern day too. We just consider it rude to be so explicit about it.)
To be fair, our modern concept of democracy really is quite shitty and the only reason we use it is because it is better than anything else we came up with so far.
But generally the notion that the common person cannot be entrusted with politics holds true even if we find it distasteful. The average person is a fucking idiot and objectively not qualified to decide on political matters.
Compounding the problem, this environment rewards charlatans and sociopaths. There will always be some that will exploit a weak spot in the system, in bad faith, no matter what the system is.
Without knowing his works, I'd argue for him that he's right to some extent towards an uneducated population, BUT the reason we have universal suffrage is that our founding fathers assumed that:
Everyone would be well-educated and make rational if not reasonable assumptions about politicians (eg, not elect morons who immediately try and sabotage the government, citizenry, and friends)
Politicians would serve as public servants and would be even better educated and would work hard to brush up on things so that the common man wouldn't have to learn the ins and outs of complicated decisions in terms of complex trade agreements, city planning and zoning law, and universal medical systems that work across state lines.
Obviously, it didn't quite go that way. But it's why I'm such an advocate for good public schools and free education, because it pays itself back in spades when it comes to R&D/innovation and an informed populace who make the country and world a better place to live.
The founding fathers did not believe in universal suffrage; at the time only people who owned land could vote--to say nothing of even less privileged groups than that--and they were fine with that policy, in part because these were considered to be the people with the most skin in the game.