容易得到的东西，是靠不住的；轻易许下的诺言，不值得信赖。

我们读书是为了发现自己是谁。

Don't interfere with anything in the Constitution. That must be maintained, for it is the only safeguard of our liberties. And not to Democrats alone do I make this appeal, but to all who love these great and true principles.

The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny...'

To write is to exorcise the demons that live within us.

最大多数人的最大幸福是道德和立法的基础。

智者不会羞于求知，因为他知道，知识的海洋是无边无际的。