How do you know when you are wrong? This question troubles me, given that the error can reside exactly in the mechanism of deciding right from wrong.

John Nash, played by Russel Crowe in the Beautiful Mind, referred to his schizophrenia as a problem that can be solved. The doctor replied You can’t reason your way out of this! ... Because your mind is where the problem is in the first place!

The doctor’s point of view seemed to be the right one, until the moment Nash recognizes that little Marcee, one of his imaginary characters, never gets old! Marcee can’t be real; she never gets old! From this moment on, Nash’s solution was to train himself to double check his perception by asking external people. An example of this can be seen in one of the final scenes when the Nobel prize representative contacts him about the possibility of him being awarded the prestigious prize.

In the case of John Nash the ending is a happy one, even if he suffered from one of the most severe problems of perception. Yet, the question remains of what should our thinking process be to even have the chance of considering the possibility of our Marcees to be unreal.

So, how do you know when you are wrong?