The best mathematics is not just correct; it is illuminating.
A long habit of not thinking a thing wrong, gives it a superficial appearance of being right.
人心的差异,就像人的面孔一样各不相同。
每本书都有一个灵魂,是写它的人和读它并梦想它的人的灵魂。
"The truth is rarely pure and never simple."