为了将关心转变为行动，我们需要发现问题，找到解决方案以及评估后果。但是世界的复杂性使得这三步都难于做到。
【释义】君子的言论，真实可靠且有证据。
登山不因为艰难险峻就停止攀登，那么最终必定能登上峻岭。
Sometimes, I think the purpose of life is to reconcile us to its eventual loss.
The best way to learn econometrics is by doing—working with real data and real problems.
The farmer is the only man in our economy who buys everything at retail, sells everything at wholesale, and pays the freight both ways.