Why Truth-Finding Rejects Democracy but Politics Requires It

Steven Weinberg records a complaint that sociologists of science make against physicists: that scientists fight for their preferred theories rather than negotiating a settlement, and that this is somehow improper.

The physicists' reply is that physics is not a democracy. You do not determine the correct theory by polling physicists. A new theory must prove itself, and once it has, everyone is obliged to accept it regardless of preference or seniority.

Notice that both sides agree on the premise. Neither the sociologists nor the physicists think majority opinion determines what is true. They disagree about conduct, not about that.

The Puzzle

Now set this beside politics, where we do decide by majority.

Grant, for the sake of argument, that elections mean something. Then politics is also, at least partly, an attempt to find something out: which policies would benefit the most people. That is a question with better and worse answers, and evidence bearing on them.

So we have a strange arrangement. In humanity's most successful truth-seeking enterprise, we reject democracy. In our most consequential political enterprise, we insist on it.

Either we are using the wrong method in one of them, or something distinguishes the cases. It is worth working out which.

The Resolution

The difference is not in the subject matter. It is in the strength of the forces trying to bend the answer.

Einstein was a patent clerk in Bern when he published special relativity. He had no institutional power, no funding to protect, and no economic interest riding on the outcome. And crucially, neither did anyone else: no industry stood to lose a fortune if simultaneity turned out to be relative. There was no lobby for the ether.

Physicists are personally invested — they push their own theories, defend their reputations, and occasionally behave badly. But the external pressures are weak. Nobody is paying to have a result come out a particular way, because there is rarely money in the answer.

Politics is the opposite case. The self-interest of groups, firms, and individuals is not a distortion of the process; it is most of the process. Every question has parties who will gain or lose enormously depending on the answer, and they have the resources to pursue that interest.

Why This Settles It

Given weak external pressure, you can let the truth emerge non-democratically. Leave physicists to argue and the better theory wins, eventually, because there is nothing powerful enough to prevent it. The mechanism is slow and undignified but it works.

Given strong external pressure, you cannot. Leave the interested parties to sort out policy and you do not get the truth; you get the preference of whoever has the most resources. Finding the policy that benefits the most people is simply not their objective, and no amount of expertise fixes that, because the problem is not a deficit of knowledge.

So we use democracy in politics not because it is the best method for finding truth, but because the alternative is worse. The alternative is autarchy: concentrated interests at the helm, benefiting themselves and imposing the costs on everyone else. Majority voting is a poor truth-finding procedure that has one enormous advantage — it is difficult to buy in its entirety.

What Follows

This reframing has a consequence I did not expect when I started thinking about it.

If democracy is defensible as a defence against capture rather than as a truth-finding method, then the case for it stands or falls on whether it actually resists capture. That is an empirical question, not a philosophical one.

And by that standard, a system that concentrates decisions in a few thousand elected officials — who can be lobbied, funded, and cultivated individually — is doing badly. It has the epistemic weaknesses of democracy without the capture-resistance that was supposed to justify them.

A system that dispersed decisions across the whole population would be no better at finding truth. It would simply be much harder to buy. On the argument above, that is the only advantage democracy ever had, and it is worth taking seriously as a design constraint rather than an afterthought.