In response to Du Zhi's statement that "learning from the ancients is infallible, and there is no good or evil in conservative manners", Shang Yang said: "In ancient times, politics and religion were different. Which ancient people should we imitate? If the king doesn't follow suit, whose etiquette shall we observe? Etiquette should keep pace with the times and meet the actual needs. So I said, governing the people is not the way; For the benefit of the country, it is not necessary to imitate the ancients. "

"Three generations of monarchs have different rituals, and five tyrants have different laws" and "Don't rule the world together, don't forget the past" became the famous saying of Shang Yang advocating political reform.