The rational expectations hypothesis does not imply that people forecast the future perfectly; it implies that they do not make systematic errors.
理性预期假说并不意味着人们能完美预测未来；它意味着人们不会犯系统性错误。
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.
The truth is not beautiful, but it is necessary.