The fight against AIDS in China is already well underway. The Chinese government and other funders are providing major support, and they'll continue to bear primary responsibility for delivering prevention and treatment.

Rich countries can afford to overpay for things.

The world is not flat, and PCs are not, in the hierarchy of human needs, in the first five rungs.

It was really phenomenal [Warren Buffett donation]. It grew out of the friendship that we had and the fact that his plan to have his wife run the foundation and give things away changed when she tragically died.

When I say "miracle" I mean a kind of thing like a computer on a chip, or the internet, or the cellphone, that are really quite miraculous. Most people would not have predicted them, and their effect has been very, very dramatic.

I believe innovation is the most powerful force for change in the world.

Really advanced civilization is based on advances in energy.