The capacity to be alone is the capacity to love. It may look paradoxical to you, but it's not.

The one element which is of first importance in scientific management is the task idea.

I declare after all there is no enjoyment like reading! How much sooner one tires of anything than of a book!

A good illustration doesn’t just decorate the text—it expands it.

做数学的艺术在于找到那个包含所有普遍性萌芽的特殊案例。