Confucius said: “To be ignorant and like to act as you will; to be of low rank and ignore all the rules; to be living in the present and be following the norms of the past: all these will bring you trouble.”
If you are not the emperor, you cannot determine the rules of propriety, set weights and measures, or create ideographs. In the present realm, carriages have the same axle-widths, documents are written with the same characters and people follow the same norms of conduct.
But even if you are emperor, if you lack virtue, you cannot presume to create ritual or music. And even if you possess sufficient virtue, but you are not in the position of emperor, you cannot presume to create ritual or music.
Source: The Doctrine of the Mean 中庸: Commentary 28