evidence: In my lifetime, I’ve seen two demonstrations of technology that struck me as revolutionary. [...] Once it had aced the test, we asked it a non-scientific question: "What do you say to a father with a sick child?" It wrote a thoughtful answer that was probably better than most of us in the room would have given. The whole experience was stunning. [...] Three books have shaped my own thinking on this subject: Superintelligence, by Nick Bostrom; Life 3.0 by Max Tegmark; and A Thousand Brains, by Jeff Hawkins. I don’t agree with everything the authors say, and they don’t agree with each other either. But all three books are well written and thought-provoking.