In 359 BCE, Counsellor-in-chief Shang Yang 商鞅 had proposed to Duke Xiao 秦孝公 (r. 362-338) to undertake substantial reforms, mainly in the creaton of a reliable law code. Duke Xiao thereupon convened his ministers and advisors to discuss the matter.
Gan Long and Du Zhi 杜摯 belonged to the faction which voted against the need to alter the existing structure of administration, mainly with the argument that a law code would deviate from the instructions made by the ducal ancestors and the regulations of the royal house of Zhou. These included the stable and perseverant indoctrination by "Saints" and wise men. These indoctrinations by superior persons would be sufficient to guide a state successfully, while a law code would give power into the hands of bureaucrats and undermine the position of the ruler.
Du Zhi advocated to cling to transmitted customs of rites and propriety, with the precautionary argument that "if there is not a hundredfold yield, one does not change the standard; if a vessel has not yielded a tenfold use [of its value], one does not discard it" (li bu bai, bu bian fa; gong bu shi, bu yi qi 利不百，不變法；功不十，不易器).
The dispute was conducted with fierce arguments, but in the end, Shang Yang prevailed, and his reforms were carried out.