心理学的方法必须是客观的，即使研究主观现象时也是如此。
The method of psychology must be objective, even when studying subjective phenomena.
The United States has no permanent enemies, no permanent friends, only permanent interests.
No man really knows about other human beings. The best he can do is to suppose that they are like himself.
The world is like a chessboard， whereon we may see a living knight， but we cannot see a living chess.
我不是黑帮，我不是暴徒，我只是一个取得了一些成功的普通人。
分别时南飞的鸿雁刚刚北去，今日北归的大雁又已南飞
The historian is a prophet in reverse.