The capacity of the human mind for formulating and solving complex problems is very small compared with the size of the problems whose solution is required for objectively rational behavior in the real world.

You'll never have a quiet world till you knock the patriotism out of the human race.

不管你认为你能，还是你认为你不能——你是对的。

我们必须接受有限的失望，但永远不要失去无限的希望。