《淮南子·汜论训》
由此看来，先王的制度，不适宜的就废除它；而近代的处事方法，如果是好的，就加以继承发扬。
先王之制，不宜则废之；未世之事，善则著之；是故礼乐未始有常也。
From this we see that the systems of the former kings were discarded if they were unsuitable, while the methods of handling affairs in modern times were continued and developed if they were good.