With four parameters I can fit an elephant, and with five I can make him wiggle his trunk.

All stable processes we shall predict. All unstable processes we shall control.

Young man, in mathematics you don't understand things. You just get used to them.

I would like to make a confession which may seem immoral: I do not believe absolutely in Hilbert space any more.

You insist that there is something a machine cannot do. If you tell me precisely what it is a machine cannot do, then I can always make a machine which will do just that.

There's no sense in being precise when you don't even know what you're talking about.

The total subject of mathematics is clearly too broad for any of us. I do not think that any mathematician since Gauss has covered it uniformly and fully; even Hilbert did not and all of us are of considerably lesser width quite apart from the question of depth than Hilbert.