自由不是被给予的，而是被夺取的。

Calm is contagious.

Hope is a good thing, maybe the best of things, and no good thing ever dies.

The history of science is the history of men correcting their mistakes.

自知之明的人，不埋怨人；了解命运的人，不埋怨天；埋怨别人的人，遭遇穷困；埋怨上天的人，没有志向。