Politics is for the present, while our equations are for eternity.

The Mona Lisa, to me, is the greatest emotional painting ever done. The way the smile flickers makes it a work of both art and science, because Leonardo understood optics, and the muscles of the lips, and how light strikes the eye - all of it goes into making the Mona Lisa's smile so mysterious and elusive.

Asked about the fact that Apple's iTunes software for Windows computers was extremely popular, Jobs joked, 'It's like giving a glass of ice water to somebody in hell.

Jobs did not know that Sculley had told Eisenstat he wanted to quit, but by then it didn't matter. Overnight, he had changed his mind and decided to stay. Despite the blowup the day before, he was still eager for Jobs to like him. So he agreed to meet the next afternoon.

The older I get, the more I see how much motivations matter. The Zune was crappy because the people at Microsoft don’t really love music or art the way we do. We won because we personally love music.

I think the biggest innovations of the twenty-first century will be the intersection of biology and technology. A new era is beginning, just like the digital one was when I was his age.

When you write biographies, whether it's about Ben Franklin or Einstein, you discover something amazing: They are human.