If you want to get an advance machine tool job today, you need to know calculus. We know a lot of people don't, we can't expect everyone to know calculus, what do we do? We created a huge bubble that created a huge number of jobs to build houses and to be in retail. You don't have to have a lot of skills to work in the new Gap store that opened, at the latest Starbucks branch, or to hammer a nail for a new house.

Optimists are usually wrong. But all the great change in history, positive change, was done by optimists.

I don't think the Arab Spring had much to do with energy. I think it was just the opposite, in fact. I think the Arab Spring happened because particularly young people knew they were living in a context where they could not realize their full potential, that they are being kept down by their own governments.

Combating climate change requires government policy, and most conservatives hate the idea of more government regulation. Because they hate the prescription, they deny the diagnosis.

Several technological and political forces have converged, and that has produced a global, Web-enabled playing field that allows for multiple forms of collaboration without regard to geography or distance - or soon, even language.

If we don't have a more serious energy policy, the difference between a good day and bad day for America from here on will hinge on how the 86-year-old king of Saudi Arabia manages...change.

The Arab world had a big problem of frankly venal elites. That is why these revolutions happen, because people didn't think the opportunities were being shared fairly.