《淮南子·泰族训》
所以，法度虽然存在，但一定得等到圣人出现以后才能治理好天下；音律虽然没有变，但一定得由名乐师去辨别它。
故法虽在，必待圣而后治；律虽具，必待耳而后听。
Therefore, although laws exist, they must wait for the emergence of saints before the world can be well governed; although the melody has not changed, it must be distinguished by a master musician.