Happiness is not the belief that we don't need to change; it is the realization that we can.

Thought is the most difficult task, which is why so few engage in it.

生命的历史用化学语言书写。

使用程序证明四色定理不会改变数学-它只是表明该定理是一个世纪的挑战，对数学可能并不重要。