Keys................................

     Once in Hawaii I was taken to see a Buddhist temple.   In the temple a man said, "I am going to tell you something you will never forget."  And then he said, "To every man is given the key to the gates of heaven.  The same key opens the gates of hell."
      And so it is with science.  In a way it is a key to the gates of heaven, and the same key opens the gates of hell, and we do not have any instructions as to which is which gate.  Shall we throw away the key and never have a way to enter the gates of heaven?   Or shall we struggle with the problem of which is the best way to use the key?  That is, of course, a very serious question, but I think that we cannot deny the value of the key to the gates of heaven.
-Richard Feynman,  The Meaning of It All:  Thoughts of a Citizen-Scientist