Niels Bohr

"An expert is a person who has made all the mistakes that can be made in a very narrow field. "

"Never express yourself more clearly than you are able to think. "

"Prediction is very difficult, especially about the future. "

"The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth. "

"Your theory is crazy, but it's not crazy enough to be true. "