我坐在黑暗中。很难弄清楚什么更糟糕：里面的黑暗还是外面的黑暗？

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.