偷一只狗一头猪，就称他不仁；二偷去了一个国家一座城池，却认为这是义。 

To act agreeably to our nature is virtue.

【译文】古人学习的人是为了提高自己，现在学习的人是为了炫耀给别人看。

The future of coal lies not in its quantity but in how cleanly and efficiently we can use it.

The future of democracy depends on the ability of democratic societies to reform themselves.

数学的美在于它简化复杂问题的能力。