To write is to leave a trace, to make a mark on the world.

道德规则不是我们理性的结论。

广泛地学习，专心致志，恳切地求教，多思考当前的实际问题，仁德就在其中了。

最重要的是永远不要停止提问。

And I hope you will come back here to Harvard 30 years from now and reflect on what you have done with your talent and your energy. I hope you will judge yourselves not on your professional accomplishments alone, but also on how well you have addressed the world's deepest inequities…on how well you treated people a world away who have nothing in common with you but their humanity.