没有所谓的新想法。那是不可能的。我们只是把许多旧想法放进一个心理万花筒里，转动它们，它们就会形成新的、奇特的组合。
"There is no such thing as a new idea. It is impossible. We simply take a lot of old ideas and put them into a sort of mental kaleidoscope. We give them a turn and they make new and curious combinations."
The beauty of mathematics is that it is one of the few areas of human endeavor where absolute truth can be known.
"There is no substitute for books in the life of a child."