fǎ yǔ shí biàn,lǐ yǔ sú huà 法与时变，礼与俗化
Laws Change Along with Evolving Times; Rites Shift Along with Changing Customs.
In the context of this term, “laws” refer to the administrative edicts of a ruler as well as institutions and laws. “Times” refer primarily to the prevailing social conditions. “Rites” mainly refer to a society’s moral norms and codes of conduct. In addition to social conventions and mores, “customs” also include popular sentiment. This expression means since everything is constantly changing and evolving, institutions, laws and rites must change correspondingly. It opposes being bound by tradition, favors innovation and change, and espouses the basic principle that a country’s governance should follow the times and respond to popular will. This is an example of the concept of “moving with the times” contained in The Book of Changes, and it also resonates with the concept of “putting the people first” advocated by Confucianism.
Hence there was more than one so-called wise ruler in ancient times. They gave out rewards which varied from big and small, their proscriptions might be harsh or light and their methods were not always the same. This is not because they were deliberately trying to be different, but because they changed with the evolving times and shifted as customs changed. (Guanzi)
A sage is someone who knows what causes a state to enjoy stability or fall into turmoil, someone who is aware of changing customs. When a sage rules, he hopes only to do what is good for his people. Thus he establishes appropriate principles, neither worshipping the past nor allowing himself to be bound by the present. He changes along with the evolving times and shifts along with changing customs. (Guanzi)
Thus when a sage rules, laws change with the evolving times and rites shift along with changing customs. Clothes and instruments are made to suit their uses, laws and edicts are adopted to meet actual needs. (Huainanzi)