人的欲望和其他激情，本质上是受到他自己控制的；他真正的困难在于，要知道何时需要加以控制，何时不需要。
The desires， and other passions of man， in themselves， are in his own power； his real difficulties are， to know when they are to be controlled， and when not.
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.