Shang Yang 商鞅 (c. 390-338 BCE) was a high minister at the court of the regional state of Qin 秦 during the Warring States period 戰國 (5th cent.-221 BCE). He is known as the earliest legalist thinker. His original name was Wei Yang 衛鞅 or Gongsun Yang 公孫鞅. For his merits in making the state of Qin stronger, Wei Yang was rewarded with the title of Lord of Shang 商君 (with land in Shang, today's Shangzhou 商州, Shaanxi). His political teachings are described in the book Shangjunshu 商君書 that has survived in parts.
Wei Yang was an offspring of the ducal house of Wei 衛 and was a disciple of Shi Jiao 尸佼 (ca. 390-330 BCE), who explained to him the need to promulgate written laws. In 365, Wei Yang went to the state of Wei 魏, where he became a retainer of chief counsellor Gongshu Cuo 公叔痤. He became acquainted with the reformist thought of Wu Qi 吳起 and Li Kui 李悝, who advocated the strengthening of the central government and its military. Gongshu Cuo acknowledged the high potential of Wei Shang and recommended him to King Hui 魏惠王 (r. 371-335), but suggested either to use Wei Yang’s skills or to kill him, to prevent other states profiting from his visions.
Yet King Hui did not take his counsellor's warning seriously, and Wei left in 361 for the state of Qin, where King Xiao 秦孝公 (r. 362-338) invited competent persons to support his government. With the support of Jing Jian 景監, Wei Yang was in 356 invited to an audience with King Xiao, and spoke to him of "the way of the king" (wangdao 王道) and the "way of the emperor" (didao 帝道), but King Xiao was not really interested in these topics. In a dispute with Gan Long 甘龍 and Du Zhi 杜摯, the young strategist thereupon spoke to the king about the skill of making a state stronger (qiang guo zhi shu 強國之術). This was an interesting topic for King Xiao, and he bestowed Wei Yang with the rank of left militia general (rank 10, zuo shuzhang 左庶長, see military ranks of honour), a position in which he carried out his first reform.
The first reform included the grouping of the whole population into groups of five and ten, with the aim of mutual supervision to prevent misdoing. Offences were avenged by collective liability (lianzuofa 連坐法) and the extirpation of the family in several generations (jiuzu 九族). The agricultural output was to be raised by doubling the taxes in kind and corvée for each family with two or more able-bodies males. On the other hand, surpassing the usual quota of grain and textile production was rewarded. Military achievements were highly rewarded, while private quarrels were strictly forbidden. The reform also included the abolishment of ranks of hereditary nobility (shiqing 世卿) including a "hereditary" fix income or salary (shilu 世祿) and their replacement by rewards for military services by granting land. Members of the royal house were subjected to the same rules as commoners, which means they had to serve in the army and could not enjoy privileges for punishment.
The effects of these measures were quite positive. Wei Yang was given the rank of supreme commander (rank 16, da liangzao 大良造). In 350, a second series of reform was implemented. The ancient well-field system (jingtian 井田) was given up according to which all land belonged to the king. It was replaced by private ownership of land in new structural arrangements of the fields in "roads and paths" (qianmo 阡陌) for all land alike. The whole country was divided in administrative units of commanderies (jun 郡) and districts (xian 縣). Weights and measures were standardized throughout the country, and a law code was compiled and promulgated, taking Li Kui’s earlier attempts as a model (see Fajing 法經). The ancient classical books (Shi Shu 詩書) were declared useless and illegal, and were burnt in public. The widespread custom of "wandering scholars" (you xue 游學) was forbidden – even if it had been the method by which Shang Yang himself had come to Qin. For the common populace, the most demanding reform was to strictly regulate the social contact of parents and children and between women and men. The common folk were expected to serve as no more than labour forces and soldiers. In 350, the royal seat of Qin was transferred from Yong 雍 (today's Fengxiang 鳳翔, Shaanxi) to Xianyang 咸陽.
Shang Yang's aim was to replace the ancient structure of ownership and privileges of the nobility by a bureaucratic system in which the whole country was administered by state officials subject to the king, and no one else. Standards in law and administration would secure fair and neutral procedures. The application of reward and punishment would strengthen the economy and the army. Wei Yang’s penal law was infamous for inflicting severe punishment even for minor crimes (qing zui zhong fa 輕罪重罰). Lord Shang explained that power of the army of Qin and its economic prosperity might eventually make it master over the other regional states.
In 338, King Xiao passed away and was succeeded by King Huiwen 秦惠文王 (r. 338-311), who was less inclined to continue the drastic reforms which Shang Yang had implemented. King Huiwen was supported by most of the former nobility whose privileges the reform had curtailed. Moreover, Shang Yang had once arranged for the punishment of King Huiwen's teachers Gongsun Qian 公子虔 and Gongsun Jia 公孫賈 when he was still a crown prince. The sovereign decided to take a drastic step, had Shang Yang arrested and punished him by being torn apart by four chariots (chelie 車裂). Following the law he had initiated himself, Shang Yang's family was extinguished (yizu 夷族). Yet many aspects of Shang Yang's law were so efficient that King Huiwen retained them.