数学的美在于它是永恒的，它不会改变。
Not hammer-strokes， but dance of the water sings the pebbles into perfection。
I prefer liberty with danger to peace with slavery.
Every scientific discovery should be measured by its contribution to human welfare.
I have always wished for my computer to be as easy to use as my telephone; my wish has come true because I can no longer figure out how to use my telephone.
Illustrations should not just decorate the text; they should expand it.
The only way to do great work is to love what you do.