> how DO you establish some kind of shared understanding of the world for a very broad "we"?

I think one can't undo decades of living in a completely separate social millieu, even in the same city in the same generation, by pointing at a website. How much less so when people come from different parts of the country, or even neighbouring countries, or even are from different continents. It takes time, and patience, and a lot of getting it wrong and still not giving up.

It also helps to not drift apart in the first place. How many people are ignored or even mocked for being not so intelligent or other issues -- until they "become a problem", or rant at people on the bus, and then the other people can't figure out why they have no way to reach them, a person who they didn't even see until they became a problem. At that point it may or may not be possible anymore, but it didn't begin at the point where it became too problematic for us to ignore.

Heck, how often do "stupid" people get gleefully blamed for being gullible and getting exploited? A lot of things that are shrugged off with "makes business sense" do hurt real people, pile on real bitterness onto a life that may already be hard enough. The bitterness doesn't disappear just because it's ignored or even censored, to the contrary.

I would say that we didn't lose goodwill and solidarity towards each other because of language, differing sets of agreed on facts, but we somehow shed our goodwill and solidarity, and then used language to try and cover it up. Now language is losing its power, facts cease to matter, wise or knowledgeable people command no respect -- but that may be more a symptom than a cause.

To put a sharper point on it: when clever slogans were still useful to get people in line and to exploit them systematically, the intelligentsia didn't exactly scream bloody murder and went on strike, it for the most part went along. So now factuality doesn't matter anymore, tribes and slogans do. Predictably, understandably so. This cannot be repaired without acknowledging intellectual dishonesty, and misdeeds against "the common man", something neither government or corporate or intellectual elites seem to be prepared to do in earnest.

> They who have put out the people's eyes reproach them of their blindness.

-- John Milton

Yet I can talk with a person and not be able to follow their argument at all, or flat out disagree with that they consider to be fact, but still know from their body language and past interactions that they have goodwill towards me. If I also feel goodwill towards them and they know that, we may not "learn" something from each other that day, but even then that conversations can be a pleasant experience that increases our familiarity and sympathy. If I just act standoff-ish until I'm convinced the other person is thinking all the right things, I'll never get anywhere.

Think how even animals of different species sometimes can form friendships and arrangements without exchanging a single abstract concept. Or how small kids that don't speak the same language might still play and build together just fine (the awkwardness and getting hung up on pointless stuff seems to come later in life), and how we learn language in the first place just based on some basic trust and being allowed to experiment. If you have the mutual goodwill, it's not complex, it happens "by itself". Without it, it gets complicated or even impossible. And I think it stands to reason that the stronger, wealthtier, more knowledgeable etc. party should always be expected to be more generous and more patient, and offer goodwill by default, even when its not reciprocated yet.

My 2 cents, etc.