The present situation in physics is as if we know chess, but we don't know one or two rules.
Richard P. FeynmanPeople may come along and argue philosophically that they like one better than another; but we have learned from much experience that all philosophical intuitions about what nature is going to do fail.
Richard P. FeynmanWhat 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.
Richard P. Feynman