The merit of Marx is that he suddenly produces a qualitative change in the history of social thought. He interprets history, understands its dynamic, predicts the future, but in addition to predicting it, he expresses a revolutionary concept: the world must not only be interpreted, it must be transformed.

他不是在忙着出生，而是在忙着去死。

学习数学的唯一方法就是做数学。

贪心不知足易招侮辱，不如节俭而守廉洁之气。求取功名而冒犯节义，不如节俭而成全节义。巧取豪夺而致积怨，不如节俭而养心性。放纵自己满足欲望，不如节俭而安定性情。

The world is a stage, but the play is badly cast.