bi 比, comparative legal cases

Bi 比 were comparison-based adjudication instruments, a judicial system used to adjudicate crimes not explicitly covered by existing laws by referencing similar statutes or precedents. This practice became an essential source of law in ancient China.

The origins of bi date back to early times. The ritual Classic Zhouli 周禮 (part Qiuguan 秋官, chapter Da sikou 大司寇), states that for lawsuits among commoners (shumin zhi yusong 庶民之獄訟), judgments shall be based on established legal precedents of the state (yi bang cheng bi zhi 邦成弊之). Jia Gongyan 賈公彥 (7th cent.) explains that for cases with prior rulings (you duan shi 有斷事), judgments should follow established decisions (yi jiu shi duan zhi 依舊事斷之). If there is no specific statute, similar cases should be referenced to determine the verdict (qu bi lei yi jue zhi 取比類以決之).

By the Qin period 秦 (221-206 BCE), this system evolved into the practice of "referencing statutes for analogous application" (yin lü tiao bi fu 引律條比附). The Yunmeng Qin Bamboo Slips 雲夢秦簡 (part Falü dawan 法律答問) records examples of such application. If a servant commits adultery with the master's wife, it should be judged by comparing (bi) it to the crime of assaulting one's master. If people fight and someone injures another person's lips, it should be judged in comparison to causing bodily harm.

By the early Han dynasty 漢 (206 BCE-220 CE), this practice was formally institutionalised. Cases that the Chamberlain for Law Enforcement (tingwei 廷尉) could not resolve were required to be submitted along with applicable legal statutes for analogous comparison (bi). Over time, this led to the establishment of specialised legal provisions such as: jue bi shi 決事比 "judgment by analogy", si zui jue shi bi 死罪決事比 "judgment by analogy for capital cases" or ci song bi 辭訟比 "comparison-based adjudication for disputes". These precedents accumulated into a structured legal framework, making bi one of the formal sources of law, standing alongside the statutory law (lü 律) and administrative orders or sub-statutes (ling 令).

By the Tang period 唐 (618-907), the term bi was no longer used explicitly. However, the Tang Code (see Tanglü shuyi 唐律疏義) included a provision in the chapter Mingli 名例 "General principles", namely the section Zhu duan zui wu zhengtiao 諸斷罪無正條 "For all crimes without direct statutes". This comparison-based adjudication system worked with the guiding principle that if the ruling may acquit the defendant, a more severe case shall be referenced to clarify the lighter one. If the ruling may convict, a lighter case shall be referenced to clarify the more severe one (qi ying chu zui zhe, ze ju zhong yi ming qing; qi ying ru zui zhe, ze ju qing yi ming zhong 其應出罪者，則舉重以明輕；其隱入罪者，則舉輕以明重).

From the Song dynasty 宋 (960-1279) onward, the term bi was replaced by li 例 „precedent“. The Ming 明 (1368-1644) and Qing 清 (1644-1911) dynasties further developed this system under new terms such as tiaoli 条例 "regulations" and fuli 附例 "supplementary provisions", which were essentially evolved forms of bi.

The difference between bi and li is a chronological and statutory one. When there is no direct legal statute (lü wu zeng tiao 律無正條), a similar law is referenced and applied by analogy—this is called bi. In contrast, li refers to applying past cases (precedents) as a basis for the judgment of actual cases.