Guided only by their feeling for symmetry simplicity and generality and an indefinable sense of the fitness of things creative mathematicians now as in the past are inspired by the art of mathematics rather than by any prospect of ultimate usefulness.

I'm a believer in belief. Faith is something that works - it causes people to do things it has results. It's an intangible indefinable very real thing. And it moves people sometimes to atrocity. And sometimes to survival.

The world is full of musicians who can play great and you wouldn't cross the road to see them. It's people who have this indefinable attitude that are the good ones.