数学的美在于它既是艺术又是科学。
The beauty of mathematics is that it is both an art and a science.
The struggle of man against power is the struggle of memory against forgetting.
礼义廉耻，可以用来要求自己，不可用来要求别人。要求自己则能少犯过失，要求别人则难以与人和睦相处，难以与他人相处就不合乎处世之道。所以君子只严格要求自己，小人则对别人求全责备。