The secondary rules are those that provide for the creation, alteration, and extinction of primary rules.

如果你愿意，可以错误地思考，但在任何情况下都要为自己思考。

晏子春秋

The only thing necessary for the triumph of evil is for good men to do nothing.

现在如果送给别人很少的东西，却希望人家回报很多的东西，那么，人们就会怕你再送东西给自己了。