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.

The existence of a legal system depends on the acceptance of secondary rules by officials.

The highest purpose is to have no purpose at all. This puts one in accord with nature in her manner of operation.

The great powers are always searching for opportunities to gain power at the expense of rivals, and to dominate the system.