In the paper we argue that it is difficult to distinguish pathological and non-pathological beliefs on the basis of their epistemic features. Then we consider some of the moral and legal implications of our thesis, focusing in particular on the role of beliefs in the attribution of moral responsibility and legal accountability for criminal actions that are motivated by those beliefs.
Delusions fail to meet many epistemic standards. It might look like they are not beliefs which are aimed at truth or governed by a norm of truth, that they are not responsive to evidence in the ways which ordinary beliefs typically are. But non-delusional beliefs also share such features. For instance, most people are vulnerable to positive illusions, considering themselves (and sometimes their romantic partners) to be above average, or better than most other people, when asked about positive traits and abilities. Moreover, people tend to exhibit unrealistic optimism about their future underestimating their likelihood of experiencing negative events, and overestimating their likelihood of experiencing positive events.
Here is another example: in self-deception beliefs include a motivational element which can involve the misreading or ignoring of evidence in coming to a belief. Consider the person who has the false and motivated belief that his wife is faithful. There may be evidence available to the person that his wife is unfaithful (he sees that she arrives home late, that she is uninterested in him, and so on). But he is highly motivated to believe that his wife is faithful.
The epistemic feature of delusions that is considered most distinctive—resistance to counterevidence—is actually a very common feature of beliefs. Once they adopt a hypothesis, people are very reluctant to abandon it, even when copious and robust evidence against it becomes available. Given that delusions share many epistemic features with non-delusional beliefs, are we justified in considering the presence of delusions as a sufficient reason to determine whether agents are morally responsible and legally accountable for their actions?