The surprising thing about this paper is that a man who could write it--would. - John Edensor Littlewood

The difference when you do know (when, for example, we are looking for a new proof) is enormous. Like a Bridge problem 'if the thing is possible it must be necessary to lead the Ace and trump with the Ace in Dummy.'

A good mathematical joke is better, and better mathematics, than a dozen mediocre papers.

Besicovitch and Harry Williams asked me what God was doing before the Creation. I said: 'Millions of words must have been written on this; but he was doing Pure Mathematics and thought it would be a pleasant change to do some Applied.'