The true value of a forest isn't measured in board feet, but in biodiversity and carbon sequestration.

受过教育的心灵的标志是能够思考一种思想而不必接受它。

志向远大之人，必须谨慎选择自己所承担的任务，有才华之人，必须选择一个值得投靠的人。

语言是我们拥有的最强大的武器，因为我们可以用它改变世界。

That's exhilarating if you're doing well, and very crushing if you're not. It leads, in the worst cases -- in the analysis of a sociologist like Emil Durkheim -- it leads to increased rates of suicide. There are more suicides in developed, individualistic countries than in any other part of the world. And some of the reason for that is that people take what happens to them extremely personally -- they own their success, but they also own their failure.