"I have often been asked: What do you think about God? I have said that we cannot know for sure whether God exists or not. But I don't believe in a personal God."

"Einstein was wrong when he said, 'God does not play dice'. Consideration of black holes suggests, not only that God does play dice, but that he sometimes confuses us by throwing them where they can't …"

"I'm an optimist. I think that the human race will find a way to survive."

"We are in danger of destroying ourselves by our greed and stupidity. We cannot remain looking inwards at ourselves on a small and increasingly polluted and overcrowded planet."

"The universe is a giant puzzle, and I'm trying to put the pieces together."