Polarisation and Democracy: When the Public Cannot Agree on the Facts

A worst-case scenario, and what it tells us about the ground beneath our disagreements

Let me tell you about the town of Ashbourne-on-Weir, which does not exist, but which I suspect you have visited before under a different name.

On the bridge at Ashbourne-on-Weir

One autumn night, the old stone bridge over the Weir collapses. Nobody is hurt, but the town is cut in two. By morning, there are two accounts of what happened. The local paper, the Ashbourne Sentinel, reports that decades of council underinvestment in infrastructure finally caught up with a structure that engineers had flagged as failing eighteen months prior. A newer outlet, Weir Truth, reports that the bridge was brought down deliberately, as part of a redevelopment scheme benefiting a councillor's brother-in-law, and that the 'engineer's report' is a fabrication invented after the fact.

Here is the part that interests me. The town does not argue about what to do about the bridge. It argues about whether the bridge fell down at all in the way anyone claims. Two camps form, and they do not merely disagree about policy; they disagree about the event.

Ashbourne now has two newspapers, two Facebook groups, two sets of 'independent' investigators, and, within a year, two competing parish councils, each insisting the other is not legitimate. Neighbours who have shared a hedge for thirty years stop speaking. The annual fete is cancelled because nobody can agree on whose flag it is safe to fly outside the marquee.

Nobody in Ashbourne is stupid. Nobody is even particularly malicious. They are simply doing what any of us would do when the shared floor beneath a disagreement gives way: they go looking for solid ground, and they find it in the account that confirms what their friends already believe.

Within eighteen months, Ashbourne has, for all practical purposes, stopped being one town. It has become two towns that happen to share a postcode.

This is fiction. It is also, more or less, the polarisation a great many real democracies are quietly sliding towards, and I think it is worth being honest about why it is so much worse than ordinary political disagreement and why the usual remedies (more debate, more fact-checking, more civility) tend not to touch it.

Polarisation: Disagreement Is Not the Disease

Democracies are built to survive disagreement. That is, in a sense, their entire design brief. What they are not built to survive is the disappearance of a shared factual floor beneath the disagreement: the situation in which citizens no longer share enough common ground even to know what they are disagreeing about.

Hannah Arendt drew this distinction with more precision than almost anyone since. She separated matters of opinion, which are properly and permanently contestable - how should we tax wealth, what should we do about immigration, how much risk should a society tolerate - from matters of factual truth, things like whether an event happened, which she thought occupy a different category altogether. Facts, she wrote, are beyond agreement and consent; unwelcome opinions can be argued with or compromised upon, but unwelcome facts possess a stubbornness that nothing can move except outright lies.

Her worry, writing in the aftermath of totalitarian propaganda, was not that people would come to hold false opinions because they always have, and a free society survives that easily. Her worry was subtler and more corrosive: that once liars succeed in getting everything treated as 'mere opinion', even well-established facts become debatable and people lose their bearings entirely. (Does 'alternative facts' sound familiar?) Having lost those bearings, they do not become sceptics. They become desperate for certainty, and they find it in whichever voice reassures them most confidently, regardless of whether that voice is telling the truth.

Ashbourne's tragedy is not that its residents disagree about redevelopment policy. It is that they no longer agree the bridge fell down for the reason anyone says it did. Once that floor is gone, there is no debate left to have: only two sealed rooms, each certain the other is lying.

Bubbles and Chambers Are Not the Same Room

It has become fashionable to blame all of this on 'echo chambers', but the philosopher C. Thi Nguyen has made a distinction here that I think deserves to be far better known because it changes what we think the remedy should be.

An epistemic bubble, in Nguyen's terms, is a structure in which relevant voices have simply been left out, and often with no ill intent at all, through the ordinary business of following people we already agree with. Members of a bubble merely lack exposure to certain arguments; they haven't heard the other side. This is fixable in the way we normally imagine: show someone the missing information, and the bubble tends to pop.

An echo chamber is a different and much harder animal. There, other voices are not merely unheard; they have been actively discredited in advance, so that members are brought to systematically distrust any outside source before they even encounter it. This is a structure that operates less like an information filter and more like the mechanics of a closed community that has been taught, in advance, to treat every external witness as a liar. And crucially, while a bubble bursts fairly easily on contact with contrary evidence, an echo chamber does the opposite: contrary evidence gets reinterpreted as further proof of the conspiracy, and the chamber only tightens. (Hmmm ... sounds a lot like today's media, doesn't it?)

This is why 'just show them the facts' so reliably fails as a strategy for reaching someone in Weir Truth's camp. You are not popping a bubble. You are, from inside the chamber, simply one more voice that has already been pre-discredited and your very insistence can be read as confirmation that you are part of the cover-up. Escaping an echo chamber typically requires something closer to a wholesale rebuilding of one's belief system, not the addition of a single new fact.

What This Asks of Us

I do not think the answer is to despair of shared reality nor to retreat into the comfortable relativism that says everyone simply has 'their truth'. Arendt's whole point was that this relativism is precisely the soil totalitarian lying grows in. The fact that Ashbourne's bridge fell for engineering reasons and not from sabotage is not up for negotiation, however satisfying it might be to one faction or the other to believe otherwise.

But it does ask something more demanding of us than simply 'doing our own research' or trusting the institution we already trust. It asks us to notice the difference, in ourselves, between genuinely weighing an unfamiliar source and reflexively discrediting it because of who said it. It asks us to be suspicious of any account, including our own faction's, that requires us to believe our neighbours are not merely wrong, but lying. And it asks something of our institutions, too: that they earn back the kind of authority that can only be built through consistent, verifiable truthfulness, since no law can force a public back into trusting them.

The bridge at Ashbourne is a small, invented catastrophe. But the mechanism by which it splits a town in two, the substitution of tribal certainty for a shared world, is not invented at all. It is, I think, the defining epistemic challenge of contemporary democratic life, and it deserves rather more of our attention than the noisier arguments about policy that sit, however loudly, on top of it.

Kathy Postelle Rixon is Chair of The Philosophical Society: Oxford and a Cambridge researcher. You can reach her at kathy@magicinharmony.com.