The true measure of a forest's worth isn't in board feet of timber, but in centuries of ecological balance.

I am always glad to think that my education was, for the most part, informal, and had its roots in the soil.

如果我失败了，我会再试一次，再试一次，再试一次。如果你失败了，你会再试一次吗？人类的精神可以承受比我们意识到的更糟糕的情况。重要的是你如何结束。你会坚强地结束吗？

领导力是关于愿景和责任，而不是权力。

煤炭的真正价值在于我们如何负责任地开采和使用它。