Well private money can take risks in a way that government money often isn't willing to.

The computer was born to solve problems that did not exist before.

A company needs to have good business reflexes, to be able to marshal its forces in a crisis or in response to any unplanned event.

I’ve been waiting more than 30 years to say this: “Dad, I always told you I’d come back and get my degree.” I want to thank Harvard for this timely honor. I’ll be changing my job next year … and it will be nice to finally have a college degree on my resume.

I have to admit that business-type thoughts do sneak into my head: I hope our customers pay us, I hope this stuff is decent, I hope we get it done on time. The little additions and subtractions that one has to do. Take sales, take costs and try to get that big positive number at the bottom.

With polio, we've gone several years with no polio in all of Africa, but now with this we're having to go and mop up in that whole region, so it's a bit of a setback for polio. So in parallel we have to go back and get rid of those cases.

This [philanthropy] work is even more fascinating. It requires us to think harder about how we build partnerships, who we get behind. And yet we get to see progress that in some ways is even more profound than the great advances that digital technology has provided.