今天我们必须负责任地开采煤炭，这样我们的孩子才能继承能源安全和健康的环境。

To lead in this industry, you must respect both the land and the people who work it.

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.

最伟大的摄影师是那些学会如实地看世界，然后再看它可能成为什么样的人。

The historian is a prophet looking backward.

做出伟大工作的唯一方法就是热爱你所做的事。

Mathematics is the organ with which we comprehend the phenomena of nature.