"But in fact, isn't that man's very purpose on earth--to do things, change things, run things, make a better world?" "No!" "What is his purpose, then?" "I don't know. Things don't have purposes, as if the universe were a machine, and every part has a useful function. What's the function of a galaxy? I don't know if our life has a purpose and I don't see that it matters. What does matter is that we're a part."