If sleeping and dreaming do not perform vital biological functions, then they must represent nature's most stupid blunder and most colossal waste of time.

It is a common failing–and one that I have myself suffered from–to fall in love with a hypothesis and to be unwilling to take no for an answer. A love affair with a pet hypothesis can waste years of precious time. There is very often no finally decisive yes, though quite often there can be a decisive no.

Mr. Chairman, ladies and gentlemen, I am told that someone accused me of saying that if the Ministry of Fuel and Power were boring for coal and they went through a layer of gold nine feet thick they would throw it away because they wouldn't know what to do with it, Sir, I only said four feet thick.