If we have optimism without empathy then it doesn't matter how much we master the secrets of science. We're not really solving problems, we're just working on puzzles.

Now, we put out a lot of carbon dioxide every year, over 26 billion tons. For each American, it's about 20 tons. For people in poor countries, it's less than one ton. It's an average of about five tons for everyone on the planet. And, somehow, we have to make changes that will bring that down to zero.

I am not a huge gamer. My son knows a LOT more than I do about what is cool on Xbox. I played Halo but the sports games that the whole family can use are the things I use the most. I threw the javelin very very far!

As we have taken diarrhea and pneumonia down, even malaria down quite a bit, the portion of the days that are very early in that 5 years - the first month, the first day - it's about half now. Yet that's the part we understand the least.

When I walk into a grocery store and look at all the products you can choose, I say, "My God!" No king ever had anything like I have in my grocery store today.

The returns from investing in poor people are just as great as the returns from investing in the business world... and have even more meaning

The leader needs to create an environment in which people can analyze the situation and develop a good response.