数学不是一项观赏性运动；要理解它，必须积极参与其中。

The spread of liberal democracy and the integration of the world economy have created a situation in which the major powers are no longer willing to risk war with one another.

Look at the stars, look how they shine for you.

没有道德规范的效率只是在错误的方向上加速。

科学不在于永远正确，而在于逐渐减少错误。