You probably think that lying is wrong. According to the philosophical view known as the error theory, this thought ascribes wrongness to lying, but wrongness does not exist. This means that lying is not wrong. You may think that in that case lying is permissible. But according to the error theory, the thought that lying is permissible ascribes permissibility to lying, and permissibility does not exist either. So the error theory says that lying is neither wrong nor permissible. And it says the same thing about anything else you may want to do.

At first glance this theory may seem crazy. But the arguments for the error theory are surprisingly strong. Suppose that you are convinced by these arguments. If so, what should you do? Should you stop believing that lying is wrong? Should you just tell lies whenever you feel like it?

Defenders of the theory give different answers to this question. Some think that you should simply stop believing that lying is wrong. Others agree that you should stop believing this, but add that you should instead start to pretend that lying is wrong. And some think that you should keep believing that lying is wrong even though this belief is inconsistent with your belief in the error theory.

___

"Just as a theory can be true if we do not believe it, a theory can also be true if we cannot believe it"

___

Opponents of the theory often criticise these answers: they say that giving up your belief that lying is wrong would have bad consequences, that pretending that lying is wrong will not motivate you not to lie, and that it is hard to knowingly have inconsistent beliefs.

But I think these answers face a different problem. Most defenders of the error theory only defend this theory about moral judgements. I think, however, that the best arguments for the error theory support a general error theory about all normative judgements: all thoughts about what is right, wrong, permissible, good, bad, a reason for action, for belief, and so on. If this general error theory is true, there is nothing whatsoever that you should do. So there is then also nothing whatsoever that you should do if you come to believe the error theory.

The arguments for this general error theory are not direct arguments for the theory, but are instead arguments against the alternatives to the theory. When I consider each of these arguments on its own, I am convinced that it is sound. But when I consider all of them together, something strange happens. I am unable to form a belief in the theory they support: a general error theory about all normative judgements. Something stops me from forming this belief.

SUGGESTED READING What Is Truth? Four Different Answers By Simon Blackburn What is stopping me? I am not entirely sure, but I think it is this. When we have a belief, we cannot at the same time explicitly think that there is no reason whatsoever for this belief. For example, if we believe that Socrates was a philosopher, we cannot at the same time explicitly think that there is no reason whatsoever to believe that Socrates was a philosopher. If we did think this, our belief that Socrates was a philosopher would disappear. Since thoughts about reasons for belief are normative judgements, a general error theory about all normative judgements entails that there is no reason to believe anything. So it entails that there is no reason to believe this general error theory itself. I think that stops me from believing the theory. And I think it also stops anyone else from believing the theory.

If I am right that we cannot believe this general error theory, defenders of the theory do not need to answer the question what you should do if you come to believe the theory. For if you cannot believe a theory, the question what you should do if you come to believe it will never arise. Of course, according to this general error theory, there is nothing whatsoever that you should do. But if you cannot believe the theory, this cannot make you believe that there is nothing whatsoever that you should do. Defenders of this theory therefore avoid the problems that other error theorists face when they try to answer the question what you should do if you come to believe the theory.

You may think that our inability to believe this general error theory is itself a problem for the theory. But I do not think it is. Just as a theory can be true if we do not believe it, a theory can also be true if we cannot believe it. Of course, if we cannot believe a theory, we cannot sincerely say that it is true. But we can defend the theory without saying that it is true: we can put forward arguments against the alternatives to the theory and say that these arguments together seem to show that the theory is true. As long as we do not say that these arguments actually show this, we are not insincere. Moreover, if we did need to be insincere in order to defend this general error theory, that would not be a problem for the theory. It would merely be a problem for us.

So is this general error theory true? Since I cannot believe the theory myself either, I do not think it is. But I do think that the arguments against the alternatives to the theory together seem to show that the theory is true. Our inability to believe a general error theory about all normative judgements may explain why the philosophical debate about the nature of these judgements has been going on for such a long time without reaching a consensus: because we have been circling around a truth that we cannot believe.

Bart Streumer will be taking part at the Institute of Art and Ideas' philosophy and music festival HowTheLightGetsIn at Hay, UK, between 24-27 May. Find out more here.