刚强纯洁的高尚人品，要在烈火般艰苦的斗争中锤炼；惊天动地的丰功伟业，必须在薄冰般险恶的环境里前进。
译文：人心就像天空和深渊。心的本体，无所不包，原本就是一个天。只是因为被私欲所阻碍，那么天的本体就丧失了。心中的道理无穷无尽，原本就是一个深渊。只是因为被私欲堵塞，那么深渊的本体就丧失了。
The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion.
Every discovery we make brings us one step closer to understanding the fundamental laws of the universe.