First you guess. Don't laugh, this is the most important step. Then you compute the consequences. Compare the consequences to experience. If it disagrees with experience, the guess is wrong. In that simple statement is the key to science. It doesn't matter how beautiful your guess is or how smart you are or what your name is. If it disagrees with experience, it's wrong. That's all there is to it.
Richard P. FeynmanI learned from her that every woman is worried about her looks, no matter how beautiful she is.
Richard P. FeynmanLooking back at the worst times, it always seems that they were times in which there were people who believed with absolute faith and absolute dogmatism in something. And they were so serious in this matter that they insisted that the rest of the world agree with them. And then they would do things that were directly inconsistent with their own beliefs in order to maintain that what they said was true.
Richard P. FeynmanThe unanswerable mysteries... the attitude that all is uncertain... to summarize it - the humility of the intellect.
Richard P. Feynman