You cannot get through a single day without having an impact on the world around you. What you do makes a difference, and you have to decide what kind of difference you want to make.

If you ask an economist what’s driven economic growth, it’s been major advances in things that mattered – the mechanization of farming, mass manufacturing, things like that. The problem is, our society is not organized around doing that.

【释义】人穷的时候不能丧失道德的标准，而发达的时候也不能背弃自己做人的原则。

数学的真正力量不在于它的复杂性，而在于它的简洁和优雅。