The philosopher Ludwig Wittgenstein once remarked that if you ask a man how much is two plus two and he tells you five, that is a mistake. But if you ask a man how much is two plus two and he tells you ninety-seven, that is no longer a mistake. The man you are talking to is operating with a wholly different logic from your own.

What we do know is that the planet is going from 7 billion people today to 9 billion. More people want to live like us, drive American- size cars, live in an American-size home, and eat American-size Big Macs. What does that mean? It means that energy demand is going to be going up.

In the hyperconnected world, there is only “good” “better” and “best.

I don't think we replaced the Soviet Union with Al Qaida. I think we replaced, we should have, Soviet Union with the merger of globalization and the IT revolution. I think it's that. That is the real challenge that we face today. Unlike the Soviet Union, it has no face, it has no missiles, but it is something that challenges every job, every city and every community.

The reason that we are becoming less equal is because of the greater requirements, secure requirements, for a good job. This goes back to the '80s basically, this started changing as globalization and the IT revolution merged, and each started to drive the other.

I've always believed the world would be a better place if more people everywhere have a chance to shape their own future and realize their full potential. I think that is what life is about.

Until we fully understand what turned two brothers who allegedly perpetrated the Boston Marathon bombings into murderers, it is hard to make any policy recommendation other than this: We need to redouble our efforts to make America stronger and healthier so it remains a vibrant counterexample to whatever bigoted ideology may have gripped these young men....And the best place to start is with a carbon tax.