A mathematician is a person who can find analogies between theorems; a better mathematician is one who can see analogies between theories and the best mathematician can notice analogies between analogies.
数学家是能在定理间找到类比的人；更好的数学家能在理论间看到类比；而最优秀的数学家能注意到类比之间的类比。
In every person, there is an abyss. Sometimes you look into it, and sometimes you don’t.
"The greatest tragedy is not the brutality of the bad people, but the silence of the good people."
In man-machine symbiosis, it is man who must adjust: The machines can't.
2004年9月13日，81岁的杨振宁在清华大学开始为本科生讲授普通物理。他说