With a library you are free, not confined by temporary political climates. It is the most democratic of institutions because no one - but no one at all - can tell you what to read and when and how.

The stranger is an element of the group itself, not unlike the poor and sundry 'inner enemies'—an element whose membership within the group involves both being outside it and confronting it.

Sometimes life hits you in the head with a brick. Don’t lose faith.

数学中最深刻的问题往往源于最简单的问题。

穷人并非不理性；他们和任何人一样理性，但他们在非常不同的约束下行动。