"I try never to write more clearly than I am able to think. "

"Prediction is very difficult, especially if it‘s about the future. "

"We are all agreed that your theory is crazy. The question which divides us is whether it is crazy enough to have a chance of being correct. My own feeling is that it is not crazy enough. "

"An expert is a person who has found out by his own painful experience all the mistakes that one can make in a very narrow field. "