There are many things in life that we value, but uncertainty is not one of them.

At first sight, this may seem to be uncontroversial. What we actually value is information, understandable as the appropriate combination of relevant questions and correct answers, the Qs and the As.

We value information because it is power: power to understand what happened, forecast what will happen, and hence choose among the things that could happen.

If you wish to buy a second-hand car, you value information about its past (was it involved in any accident? yes), its future (is it expensive to run? yes), and its present (should I haggle over the price? yes). The more information you have, the better you may shape your environment and control its development, and the more advantage you may enjoy against competitors who lack such a resource.

This applies even to stand-alone contexts: Robinson Crusoe wishes to have information about the island, even if there is nobody else. It applies even more strongly to social contexts: once Robinson Crusoe is joined by Friday, the native cannibals, the shipwrecked Spaniards, and the English mutineers, the asymmetric nature of his informational state (he has answers to questions that they lack) is enormously advantageous, to the point of being life-saving.

On the contrary, being uncertain means that none of this holds true, because you have only the relevant questions without the correct answers, only the Qs without the As.

Just remove the three yesses from the previous questions about the second-hand car and you immediately appreciate why nobody likes to be in such a state of informational deficit.

Because each of us finds information valuable and uncertainty unhelpful, one may be tempted to generalise and declare uncertainty a disvalue in absolute terms: having only relevant questions is always bad, adding the correct answers is always good.

We value information precisely because it reduces uncertainty. If you like one you dislike the other, it seems a zero-sum game. Yet this would be a mistake. A liberal, tolerant, and fair society is one in which a healthy degree of uncertainty is both welcomed and fostered.

First, one must recall that uncertainty is preferable to ignorance, for lacking answers is not as bad as lacking the questions in the first place. Imagine you did not think about asking whether the second-hand car you bought required a very expensive insurance. Often “you should have known better” only means “you should have asked”.

It is not uncertainty but rather ignorance that is an absolute disvalue. For only if you have no questions you may never get answers. Fundamentalists of all kinds know this well. This is why any society that forbids or discourages free questioning is illiberal and in need of reform.

Second, uncertainty has value insofar as it makes the relationship between questions and answers a bit more problematic, and rightly so. Sceptics love doubts that untie the As from the Qs.

The value of sceptical doubts and of the uncertainty they generate lie in the extremely demanding standards that they setup to test the correctness of our answers. A bit like driving your second-hand car under the most extreme weather conditions. So people who understand scepticism use it judiciously, as a benchmark.

Descartes was questioning the ultimate foundation of all knowledge. The task could not have been more crucial, so he choose the ultimate challenge – a malicious demon that is constantly deceiving us even about the clearest answers to the most basic questions about simple mathematical truths. He offered the ultimate answer: I think therefore I am, this much is absolutely certain.

Of course, when buying a second-hand car, you do not need to entertain such extreme possibility. And yet, some sceptical uncertainty may still be healthy, for you may not be fooled by a demon, but you might be conned by a salesman. In short, some induced uncertainty and the ability to entertain alternative answers to the same question has an epistemological value that we should not underestimate, in science as well as in everyday life.

Dogmatic societies that assume there is only one correct answer to fundamental questions – being these about abortion, same-sex marriage, dress codes, alcohol and recreational drugs, assisted suicide, or other similar divisive issues – tend to be intolerant and could definitely do with a healthy dose of uncertainty.

Finally and most importantly, uncertainty can be harnessed in order to restrain the power that comes with information, or constrain it to make it perform better. The first point is simpler. Information-as-power can easily be abused, and it is sometimes better not to empower people in the first place, rather than trust them to use their power fairly and wisely, not least because the “nice” people of today may be replaced by nastier one tomorrow.

Think about political preferences, for example: your vote should be and remain secret, no matter how free I am to ask questions about it. The same holds true about private choices, tastes, inclinations, or behaviours: your business, my uncertainty.

The second point, that some degree of uncertainty may actually be good for the overall informational state of the system, is less intuitive. To put it simply, information-as-power, if unlimited, may actually perform less well, socially, then when there are some limits. This is known, in game and network theory, as Braess’ paradox.

Sometimes, blocking roads can actually speed up traffic. Think in terms of adding some friction to the flow of information: if some questions remain unanswerable in principle (blocked, using the network traffic analogy) this actually improves the performance of the overall system. If everybody remains slightly uncertain about some topics, everybody ends up being more informed.

Each of us would like to be omniscient, at least in the sense of having access to the correct answer to any question but, socially, this would be a disaster, for boundless information leads to boundless power (omnipotence), which rationally and selfishly used breeds irreconcilable conflicts, and ultimately a gridlock.

John Rawls’ famous “veil of ignorance” is actually a “veil of uncertainty”, which exploits precisely the value of a lack of answers, in order to develop an impartial approach to justice in terms of fairness: we should determine the morality of an action or institution or custom as if we did not have an answer to the question how it would affect us, that is, which position we would hold in the issuing society that would approve of it.

In medicine, we have learnt that, at normal levels in the blood, cholesterol is an essential substance for the normal functioning of the body. Just because the usual problem is too high cholesterol, which therefore needs to be kept under control, this does not mean that excessively low cholesterol is not unhealthy as well.

In economics, we have learnt a similar lesson about inflation. For a long time we treated it as an absolute disvalue and tried to eradicate it completely, but it seems clear now that a low (as opposed to zero or negative) and steady rate of inflation is actually preferable, because it can reduce the severity of economic recessions and favour more stability.

In philosophy, it is time we learn the value of a low and stable degree of uncertainty. It is unhealthy to eradicate it completely, for a small dose of it in the social system leads to increased degrees of liberalism, toleration, and fairness, as well as more efficient flows of information.

It seems that the value of information also lies in what it can teach us about its own equilibria.