We must laugh at man to avoid crying for him.
与其后来替一个人婉惜，不如先嘲笑他算了。
A law of nature， lex naturalis， is a precept or general rule found out by reason， by which a man is forbidden to do that which is destructive of his life or takes away the means of preserving the same.
Natural experiments are a powerful tool for understanding causal relationships in the real world.
In truth, the foundation of education in general is the education of the poor.