A good mathematician is someone who can see analogies between theorems; a great mathematician is someone who can see analogies between analogies.
一个好的数学家是能看到定理之间类比的人;一个伟大的数学家是能看到类比之间的类比的人。
A covenant not to defend myself from force, by force, is always void.
有些鸟儿天生就是关不住的,它们的羽毛太鲜明,歌声太甜美、也太狂野了,所以你只能放它们走,否则哪天你打开笼子喂它们时,它们也会想办法扬长而去。