Experiment is the sole judge of the validity of any idea.

The unanswerable mysteries... the attitude that all is uncertain... to summarize it - the humility of the intellect.

A philosopher once said, 'It is necessary for the very existence of science that the same conditions always produce the same results.' Well, they don't!

What is not surrounded by uncertainty cannot be the truth.

You see, I get such fun out of thinking that I don't want to destroy this most pleasant machine that makes life such a big kick.

It is the fact that the electrons cannot all get on top of each other that makes tables and everything else solid.

The first principle is that you must not fool yourself and you are the easiest person to fool.