The whole conviction of my life now rests upon the belief that loneliness, far from being a rare and curious phenomenon, peculiar to myself and to a few other solitary men, is the central and inevitable fact of human existence.

知道自己不知道什么比聪明更有用。

Reason is immortal， all else mortal.

If you can see, look. If you can look, observe.

心之外没有事物，心之外没有事情，心之外没有道理。