种树的最佳时间是二十年前，其次是现在。
People, even more than things, have to be restored, renewed, revived, reclaimed, and redeemed; never throw out anyone.
"Causal inference requires careful thought about the assumptions underlying your analysis."
Money is concerned only with what is common to all: it asks for the exchange value, it reduces all quality and individuality to the question: How much?