I think it's fair to say that personal computers have become the most empowering tool we've ever created. They're tools of communication, they're tools of creativity, and they can be shaped by their user.

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.

So we do software for watches, for phones, for TV sets, for cars. And some of these take a long time to catch on.

Innovation is often the hidden thing, because we can't put numbers to it. And yet it's the thing that defines the way we live, the things we'd like to have for everyone whether it's health or education.

That way you can be certain to learn something you didn't know previously.

Innovation is a good thing. The human condition - put aside bioterrorism and a few footnotes - is improving because of innovation.

I think Ebola is a great example of where the world really needs to come together. The three countries where this outbreak took place have had a lot of civil war, very weak health systems. And so, it did take a while for people to understand ....that eventually what we saw was a very unique Ebola epidemic. I think it is quite impressive what's being pulled together, and I think we will be able to get this under control.