Dictatorships sometimes fall unexpectedly and quickly. And [Vladimir] Putin knows that for him, the loss of power doesn't mean a comfortable retirement, but something completely different.

I don't have enough information, and enough courage, to come up with a definite version of events. And I think it is too dangerous for me to do so.

One of my optimistic prophecies is based on the assumption that machines could have the best algorithms in the universe, but it will never have purpose. And the problem for us to explain purpose to a machine is because we don't know what our purpose is. We have the purpose, but we still ... When we look at this global picture, a universal picture, to understand what is our purpose being here on this planet? We don't know.

Solving new problems is what keeps us moving forward as individuals and as a society, so don't back down.

I'm not saying that George W. Bush did everything right. But even if you take a skeptical view of his Iraq war, [Barack] Obama made the more serious error of withdrawing his troops from Iraq early.

To my surprise I found that when other top players in the precomputer age (before 1995, roughly) wrote about games in magazines and newspaper columns, they often made more mistakes in their annotations than the players had made at the board.

The ability to work hard for days on end without losing focus is a talent. The ability to keep absorbing new information after many hours of study is a talent.