When I care about something, I care about something. I think I have an obligation as an American to - and as a citizen, as - as a human being, to help others. Smoking is going to kill a billion people this century. I've put six hundred million dollars from my own money into trying to stop the tobacco companies from getting kids to smoke and convincing adults that it's not in their health.

The fact is, the most painful and tragic lesson of the 20th century was that regimes based on racial superiority and religious hatred can't be trusted to keep their word to the international community.

One's a dog-eat-dog world, and the other one's just the opposite.

Buy what's deliverable, not what could be.

I think that most of the candidates [for presidency] can't run the railroad, and I still worry that whoever gets elected will have policies designed for political rather than practical reasons.

By speeding the transition to cleaner energy, we can improve the lives of billions of people, while also reducing the risks we face from a changing climate.

We can be certain that cities around the world will compete for the jobs that the next revival of the financial services industry will bring.