I love to try to understand first principles and be guided by that. But then, enrich them, because they won't last forever, just like everybody thought Newton had all the answers. And you probably read that, in the last of the 19th century, Harvard and others were discouraging people from going into physics because we have all the answers. And right after that, of course - we have - all this stuff is thrown out the window. And now we have whole new answers.
