Can democracy be trusted to make the right decisions? Critics of democracy tend to argue that democracy cannot be trusted in this way. They point to the difficult decisions that democratic societies face today—with regard to climate change, for example, or rising inequalities in income and wealth. Democracy is out of place in these decision-making contexts, these critics argue, because democratic citizens are too ignorant and too prone to cognitive biases and errors to be able to make the right decisions; experts should make such decisions.

Defenders of democracy have tried to refute this objection by pursuing two main strategies. The first is a moral strategy. Those who pursue this strategy argue that the value of democracy lies elsewhere, not in its ability to make the right decisions, as understood independently of the decision-making process, but in its ability to respect citizens’ equal freedom through the process of democratic decision-making itself. Decision-making by experts would undermine this equal freedom by giving some citizens—the experts—more political power, and subjecting others to their will. Since there are, in addition, valid doubts about experts being influenced by their own political agendas and being biased towards the interests of their social group, the costs of failure in making the right decisions need to be compared not with the benefits of experts’ ability to make the right decision, but with the costs of failing to respect the citizens’ equal freedom.

While democracy’s association with the value of equal freedom is fundamental, the problem with the moral strategy of arguing for democracy is that the costs of ignoring expertise can be very high, and might even involve a threat to the very ideal of equal freedom—for example, if decisions violate minority rights.

The second strategy aims to show that democracy can be trusted to make the right decisions and that it should be trusted to the extent that it does. This is often called the epistemic strategy. It gets its name from epistemology, the study of knowledge. It is so called because it draws a parallel between decision-making by people who know—the experts—and democratic decision-making. There are various ways in which people have tried to show that democracy can be trusted to make the right decisions, but the different versions of this strategy overlap on the claim that democratic decision-making can match or even outperform decision-making by experts.

A modest defence of democracy along those lines merely claims that democracy is defensible if it does not perform worse than alternative forms of decision-making, for example, decision-making by experts. This is possible if the gains of inclusive decision-making offset the costs of relying on democracy rather than on experts. A more ambitious defence resorts to ‘wisdom of the crowds’ arguments and related ideas to show that large numbers of people that bring together different perspectives on an issue are often more likely than small groups of experts to get to the right decision.

The epistemic strategy might look promising because it takes on the critics of democracy on their own terms. But that virtue can easily turn into a vice. The problem arises in relation to the role that the appeal to the capacity to reach the right decision plays in the argument. If the argument is that democracy is defensible insofar as it has the potential to generate the right decision, or at least to perform no worse than decision-making by experts, then it is not clear whether this constitutes an argument for democracy at all. If the argument presupposes that we can know, independently of democratic decision-making, what the right decision is, then why rely on democracy in the first place? Why not let those who do know make the decision? It then looks as if this strategy either ends up making democratic decision-making redundant or, if it does not, ends up defending democracy on other grounds—for example, on the grounds that it realises important moral values, as those adopting the moral strategy have argued.

The more ambitious version of the epistemic strategy fairs better in this regard because it attempts to provide a non-moral argument for why we should trust democracy. The problem with arguments of this sort, however, is that they often rely on assumptions that are not a good fit with the circumstances of politics within large societies. Indeed, it is not easy to come up with examples from everyday democratic politics that would illustrate this alleged epistemic power of democratic decision-making.

If both the moral and the epistemic strategies fail, is there a third strategy that can be used to defend democracy? I think there is. This third strategy pursues an argument from disagreement. It starts with the question of whether political decisions should be made in a democratic way or whether they should be made by those with expertise. And the answer it gives is: it depends. On the one hand, when there is expertise about the problem at hand and there is a political authority that we can trust to act on that expertise, then it appears that democratic decision-making is redundant, or at least that it is redundant on epistemic grounds. There might still be strong moral or pragmatic reasons to rely on democracy even in those circumstances, for example, if democratic decision-making increases compliance with a decision. But the higher the stakes —the more important the decision and the bigger the costs of getting it wrong—the less likely it is that these reasons should receive much weight and the more likely it is that democracy is out of place.

When there is no expertise, on the other hand, democracy looks much more defensible. These circumstances obtain when there is no fact of the matter in some decision, when decision-making comes down to establishing which alternative more people prefer—think of the case of a group of friends in need of a decision about where to go for dinner. But few democratic decisions will be like this. Most problems that democratic societies face will be such that people disagree, not just because they like different things, but because they have different perspectives on the facts. Of course, some of these disagreements arise because some people are just too ignorant of the relevant facts to form a correct opinion about what the right decision is. In that case, we are back in a scenario where democracy may well be out of place. But for many complex policy questions, even the experts disagree about what the right decision is. And when there is no one we could turn to for advice on what the right decision is, then there is a strong case for democracy.