知道我们所知道的,知道我们所不知道的,这才是真正的知识。
"A writer's duty is to tell the truth, even when it is uncomfortable."
生命中最伟大的荣耀不在于从不跌倒,而在于每次跌倒后都能站起来。
We teach a subject not to produce little living libraries on that subject, but rather to get a student to think mathematically for himself.