Who can afford to do professional work for nothing?

The history of philosophy is not, like the history of the sciences, to be considered as a mere chronological record of discoveries and errors. It is the history of the human spirit in its endeavor to understand itself and its relation to the universe.

形式化方法不是银弹，但它们是追求可靠系统的重要工具。

I want to make people feel good. That's all I wanna do.

我不完美，但我始终做自己。

Leadership means making tough decisions today that will benefit generations tomorrow.

General relativity has passed every test we’ve thrown at it, even near a supermassive black hole.