"What is it about nature that lets this happen, that it is possible to guess from one part what the rest is going to do? That is an unscientific question: I do not know how to answer it, and therefore I am going to give an unscientific answer. I think it is because nature has a simplicity and therefore a great beauty."
Richard Feynman, "Seeking New Laws," pp. 143-167, in Richard Feynman, The Character of Physical Law, New York: Modern Library, 1994. Quote is from p. 167.
At the risk of quote-mining, this appears to be Feynman's version of Wigner's famous Unreasonable Effectiveness of Mathematics argument.