成为英雄的最大障碍是怀疑自己是否会证明自己是个傻瓜；真正的英雄主义是抵制这种怀疑；最深刻的智慧是知道何时应该抵制，何时应该服从。
The greatest obstacle to being heroic is the doubt whether one may not be going to prove one's self a fool; the truest heroism is to resist the doubt; and the profoundest wisdom, to know when it ought to be resisted, and when it be obeyed.
The past is never dead. It's not even past.
I couldn't remember the reason for living, and when I did it wasn't convincing.
Do not let your fire go out, spark by irreplaceable spark.
The beauty of mathematics is that it allows us to abstract away from the physical world and focus on the underlying principles.
我们都有责任见证我们所看到的，并大声反对不公正。