Mathematics is the music of reason.

Lock up your libraries if you like; but there is no gate, no lock, no bolt that you can set upon the freedom of my mind.

Always say less than necessary.

Sustainability isn't a choice; it's our responsibility to the planet and future generations.

"To live is the rarest thing in the world. Most people exist, that is all."

The theory of economic development is the study of how the economic system generates the forces which incessantly transform it.

You are not only responsible for what you say, but also for what you do not say.

气候变化的挑战要求我们重塑发展模式。