Success is a miserable teacher. It tempts intelligent people to believe they cannot lose. And it is an unreliable guide to the future.

Don't let complexity stop you.

A first-generation fortune is the most likely to be given away, but once a fortune is inherited it's less likely that a very high percentage will go back to society.

I do normal kind of contributions, particularly for people who are going over to Africa and help highlighting global health, and that's tended to be pretty bipartisan in nature because of the coalition there exists fortunately around these global health issues. But I don't think my backing, putting a lot of money into political contributions is a way I'm going to try and help improve the world.

The general idea of the rich helping the poor, I think, is important.

Contrary to Piketty’s rentier hypothesis, I don’t see anyone on the [Forbes 400 list of the wealthiest Americans] whose ancestors bought a great parcel of land in 1780 and have been accumulating family wealth by collecting rents ever since. In America, that old money is long gone - through instability, inflation, taxes, philanthropy, and spending.

Is the rich world aware of how four billion of the six billion live? If we were aware, we would want to help out, we'd want to get involved.