每个人持续不断地努力改善自己的状况，这是公共、国家以及私人富裕最初来源的原则。
The uniform， constant， and uninterrupted effort of every man to better his condition， the principle from which public and national as well as private opulence is originally derived.
预测未来的最好方式就是创造未来。
The essence of causal inference is to go beyond the data and ask what would happen if we intervene.