On black holes: "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 be seen" - The Nature Of Space And Time, published 1996
On the reason why the universe exists: "If we find the answer to that, it would be the ultimate triumph of human reason - for then we would know the mind of God" - A Brief History Of Time, published 1988
On God: "It is not necessary to invoke God to light the blue touch paper and set the universe going" - The Grand Design, published 2010
On humanity: "We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special" - Interview in Der Spiegel, October 1988
On artificial intelligence: "The development of full artificial intelligence could spell the end of the human race. It would take off on its own, and re-design itself at an ever increasing rate... Humans, who are limited by slow biological evolution, couldn't compete, and would be superseded" - Interview with the BBC, December 2014
On the possibility of contact between humans and aliens: "I think it would be a disaster. The extraterrestrials would probably be far in advance of us. The history of advanced races meeting more primitive people on this planet is not very happy, and they were the same species. I think we should keep our heads low" - In Naked Science: Alien Contact, the National Geographic Channel, 2004
On space colonies: "I don't think the human race will survive the next 1,000 years, unless we spread into space. There are too many accidents that can befall life on a single planet. But I'm an optimist. We will reach out to the stars" - Interview in the Daily Telegraph, October 2001
On the end of the universe: ""It will take about a thousand million million million million years for the Earth to run into the sun, so there's no immediate cause for worry!" - A Brief History Of Time, published 1988
On life: "One, remember to look up at the stars and not down at your feet. Two, never give up work. Work gives you meaning and purpose and life is empty without it. Three, if you are lucky enough to find love, remember it is there and don't throw it away" - Interview with ABC's Diane Sawyer, June 2010
