Deng Xi (/ˈdʌŋ ˈʃiː/;[1] Chinese: 鄧析; Wade–Giles: Têng Hsi, c. 545 – 501 BCE) was a Chinese philosopher and rhetorician who was associated with the Chinese philosophical tradition School of Names. Once a senior official of the Zheng state, and a contemporary of Confucius, he is regarded as China's earliest known lawyer, with clever use of words and language in lawsuits. The Zuo Zhuan and Annals of Lü Buwei critically credit Deng with the authorship of a penal code, the earliest known statute in Chinese criminology entitled the "Bamboo Law". This was developed to take the place of the harsh, more Confucian criminal code developed by the Zheng statesman Zichan.
Deng is regarded as the first proponent to advocate following the li, or pattern of things. A term which refers to the processing of jade, it would be utilized by the neo-Mohists as the term identifying the logic and history of a thing in the growth of a proposition. With arguments pertaining to forms and names, Deng Xi is cited by Liu Xiang for the origin of the Xingmingjia school of names principle of xingming, as referring to the matching of words and results. Similarly utilized by Shen Buhai and Han Fei as pertaining to administration, or "Legalism", this would likely make him an important contributor to both Chinese philosophy, as especially the school of names, and the foundations of Chinese statecraft.
Associated with litigation, he is said to have argued for the permissibility of contradictory propositions, engaging in hair-splitting debates on the interpretation of laws, legal principles and definitions. However, the purpose of his concept of bian is specifically to examine and distinguish categories so as to prevent hindrances or disturbances, with inferences are then made categorically. He distinguishes great and small bian ethically rather than logically, as Xun Kuang would later (although the Mohists also had ethical discussions). Under the influence of the Mohists, Xun Kuang would suggest categorization as a key to the understanding of things.[2][3]