Shenzi 申子 "Master Shen" is a book attributed to the legalist philosopher Shen Buhai 申不害 (420-337 BCE), who acted for a long period as chief counsellor of Marquis Zhao 韓昭侯 (r. 358-333) of Han 韓 during the Warring States period 戰國 (5th cent-221 BCE).
Shen Buhai laid stress upon the use of punishment in order to strengthen the state and the position of the ruler. His book consisted of 6 chapters in two juan. The largest part of the book is lost. It is known that there existed a chapter called Junchen 君臣篇 "Lord and minister", and probably one called Sanfu 三符 "The three tallies". The chapter Dati 大體 "Great embodiment" is preserved in the collection Qunshu zhiyao 群書治要. Several other fragments are collected in various books quoting from the Shenzi. The commonly used version is the compilation by the Qing-period 清 (1644-1911) scholar Ma Guohan 馬國翰 (1794-1857) in his series Yuhan shanfang jiyi shu 玉函山房輯佚書.
Although the most important contribution of Shen Buhai to the state philosophy of legalism is the penal law (fa 法), his vicinity to Daoist thinking is clearly seen in his interpretation of the ruler's role as a kind of non-moving pivot in the state system, signifying the dao 道 "Way" (or fundamental principle of nature and cosmos). Without revealing his proper thought the sovereign was, by his own "skill of governing" (shu 術), able to make use of his ministers. Competent ministers would be remunerated, wile the incapable would be punished. Yet the very personal or "subjective" art of governing was not sufficient to govern a state efficiently: What Shen Buhai's state still lacked were "objective", universal, and reliable laws.