There is no such thing as a special category of science called applied science; there is science and its applications, which are related to one another as the fruit is related to the tree that has borne it.

一本书是与死者的对话。

我首先是个妈妈

每一个优秀的数学家至少是半个哲学家，而每一个优秀的哲学家至少是半个数学家。