Mathematics is a conversation between the past and the future.

【原文】樊迟问知，子曰：“务民之义，敬鬼神而远之，可谓知矣。”问仁，曰：“仁者先难而后获，可谓仁矣。”【译文】樊迟问怎样才是“智”，孔子说：“专心致力于（提倡）老百姓应该遵从的道德，尊敬鬼神但要远离它，就可以说是智了。”樊迟又问怎样才是仁，孔子说：“仁人对难做的事，做在人前面，有收获的结果，他得在人后，这可以说是仁了。”

In the end, we will remember not the words of our enemies, but the silence of our friends.

The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion.