你沾沾自喜，别人乐于喜欢你；你攻击你周围的某个人，其他的人哈哈大笑；但倘若你解剖你自己的灵魂，所有的人就会嗷嗷叫。——作者原注

The key to credible causal inference is not just the method, but how well the method fits the question at hand.

The true value of a mining company lies in its ability to balance profit with environmental stewardship.

最好的电影是那些不怕模棱两可的电影。