The other day, suddenly, I turned round to Patrick and started talking about insanity.
I don't know why I did this. I don't suppose he did either.
I asked him what insanity was. He didn't answer.
I told him what I thought it was. He found what I said interesting.
I said the insane person is not the person who lives in their own world. It's the person who does not accept that other people live in a different world not theirs; be that different world one of their own, equally private, or be it the public world more commonly subscribed to.
I have a friend in Durham who believes things that might lead many to think him mad if they were to judge him only by the things he believes in. Yet he is not mad at all. This is because he is able to suspend identification with his exotic world view and take up the point of view of others when he talks to them.
That process of self-abstraction, I think, makes all the difference. It is also the hallmark of courtesy towards others. Even if you are certain that you're right, you can accept that your truth is not their truth, your reality not theirs.