Scientific knowledge is a body of statements of varying degrees of certainty -- some most unsure, some nearly sure, none absolutely certain.

To guess what to keep and what to throw away takes considerable skill. Actually it is probably merely a matter of luck, but it looks as if it takes considerable skill.

What I am going to tell you about is what we teach our physics students in the third or fourth year of graduate school... It is my task to convince you not to turn away because you don't understand it. You see my physics students don't understand it... That is because I don't understand it. Nobody does.

That is the logical tight-rope on which we have to walk if we wish to interpret nature.

Fall in love with some activity, and do it! Nobody ever figures out what life is all about, and it doesn't matter.

Don't pay attention to "authorities," think for yourself.

There is no authority who decides what is a good idea.