The best time to plant a tree was 20 years ago; the second best time is now.

今天对自由民主最严重的威胁不是来自外部，而是来自内部。

The first fruit of this imagination—and the first lesson of the social science that embodies it—is the idea that the individual can understand his own experience and gauge his own fate only by locating himself within his period, that he can know his own chances in life only by becoming aware of those of all individuals in his circumstances.

"The truth is rarely pure and never simple."

The best ideas often come from listening to those closest to the problem.

——民权主义第三讲

In mathematics, the journey is just as important as the destination, for it is through the process of discovery that we truly learn.