A very beautiful piece from his memoir:
I believe that if, at the end, according to our abilities, we have done something to make others a little happier, and something to make ourselves a little happier, that is about the best we can do. To make others less happy is a crime. To make ourselves unhappy is where all crime starts. We must try to contribute joy to the world. That is true no matter what our problems, our health, our circumstances. We must try. I didn’t always know this and am happy I lived long enough to find it out.