The only fence against the world is a thorough knowledge of it.
正派人的话，明明知道了为了我好，内心感激却未必高兴；奸邪人的话，明明知道是在奉承我，但听着十分顺耳，所以未必生气。由此可知听取忠言是多么艰难。
The most beautiful as well as the most ugly inclinations of man are not part of a fixed biologically given nature, but result from the social process which creates man.
The worst thing that can happen to a human being is to lose hope.
Life is about taking risks, if you don't take risks you'll never know what you're capable of.