忧伤愁苦，就会心气滞结；忿怨愤怒，就会心气横逆不顺；惊恐畏惧，就会心气沉落不浮；拘谨固执，就会心气郁郁不释；急躁浮躁，就会心气损耗不足。

The goal of mathematics is to understand the patterns of the universe.

The first step in liquidating a people is to erase its memory. Destroy its books, its culture, its history. Then have somebody write new books, manufacture a new culture, invent a new history. Before long the nation will begin to forget what it is and what it was. The world around it will forget even faster.

我认为在生活中冒险很重要。如果你不冒险，你永远不会成长。

The true teacher defends his pupils against his own personal influence.