The idea that in some specific contexts even wildly false beliefs can promote knowledge is counterintuitive, just like the idea that a morally dubious act can have good moral consequences. But the analogy can help us. In some circumstances, an apparent offense can prevent a worse outcome from occurring. For instance, you stop a terrorist from detonating a bomb by shooting his leg and making him fall. Shooting people is bad. But stopping the terrorist may be the right thing to do in the circumstances, especially if the bomb is likely to harm other people. If less violent means of stopping the terrorist are not available to you at the time, then what you do is justifiable. Similarly, if even wildly false beliefs can play an important function by enabling imperfect human agents to acquire knowledge in imperfect situations, that counts as a powerful redeeming feature.
This notion may apply to delusions and other implausible beliefs. Without adopting the delusion, you would be overwhelmed by anxiety, puzzled and unable to engage and learn, because you would not have an explanation for your experience. You would see the dog’s actions, have a strong sense that the experience is significant, but have no clue as to what its meaning could be, and feel lost and maybe even threatened by it. Other (far more plausible) explanations for the experience (such as “This event appears significant to me because there is something wrong with my brain”) would be less likely to enhance your sense of meaningfulness and coherence and to make you feel important and engaged. Thus, they would have fewer chances of reducing anxiety and stress. Coming to believe that you suffer from a disabling mental condition would increase your anxiety and stress, and lower your self-esteem.
Adopting the delusional explanation allows you to continue to process information effectively in a situation where your capacity to learn would be otherwise compromised. It is an emergency response in a disastrous scenario, comparable to shooting the terrorist in his leg just before he detonates a bomb that is likely to harm others. Thus, adopting the delusion may have beneficial effects on your capacity to obtain knowledge, but only with respect to a situation that is already problematic. The positive effects of the delusion may be temporary and limited in scope, and will be outweighed at a later stage due to the considerable disruption caused by the delusion. By letting the delusion shape your life, you find new sources of anxiety and stress, and you are likely to experience social isolation and exclusion as well. But despite these important qualifications, the claim that delusions have benefits for knowledge is important, and has implications for treatment.
The clinical psychologist Daniel Freeman and his colleagues found that when you endorse a delusional belief with conviction (in the acute stage) you are not open to acknowledging that there may be other hypotheses explaining your experience. As a result of this finding, they argue that it is not always a good idea to challenge a delusion. If you cannot think of alternative explanations, there is nothing you can replace the delusion with, and thus when the delusion is challenged you may be left without any explanation for your experience. If delusions are sometimes beneficial, and enable you to resume learning in the way I suggested, then there may be an additional reason not to challenge them at the acute stage. Delusions may be playing the role of an emergency response, partially deceiving you but at the same time allowing you to continue engaging with the world around you, and potentially acquiring knowledge at a critical time.Lisa Bortolotti - The upside of delusional beliefs – Scientia Salon