Zhang Zai 張載 (1020-1077), courtesy name Zihou 子厚, was and one of the five great Neo-Confucian scholars of the Northern Song period 北宋 (960-1126) (Beisong wu zi 北宋五子), the others being Shao Yong 邵雍 (1011-1077), Zhou Dunyi 周敦頤 (1017-1073), and the brothers Cheng Hao 程顥 (1032-1085) and Cheng Yi 程頤 (1033-1107). Zhang was the founder of the so-called Guanzhong School (Guanxue 關學) of Neo-Confucianism.
Zhang's ancestors hailed from Daliang 大梁 (today's Kaifeng 開封, Henan), but his father Zhang Di 張迪 was prefect of Fuzhou 涪州, where he died. The children remained in Meixian 郿縣 in the prefecture of Fengxiang 鳳翔 (today in Shaanxi), a place where Zhang Zai also lived for the most of his life. The school were he assembled his disciples was in the village of Hengqu 橫渠, for which reason he is also known as "Master from Hengqu" (Hengqu Xiansheng 橫渠先生). Zhang Zai obtained his jinshi degree around 1060 and made a career as administrator for public order (sifa canjun 司法參軍) in the prefecture of Qizhou 祁州, district magistrate of Yunyan 雲巖 in the prefecture of Danzhou 丹州, notary of the administrative assistant (qianshu panguan gongshi 簽書判官公事) of Weizhou 渭州, clerk (jiaoshu 校書) in the Institute for the Veneration of Literature (Chongwenyuan 崇文院), and associate administrator (tongzhi 同知) of the Ritual Academy (liyuan 禮院) of the Court of Imperial Sacrifices (taichang 太常).
His life was influenced by the military conflicts in the border zone between the Song and the Western Xia empire 西夏 (1038-1227). For some time he served the Vice Commander-in-chief (jinglüe anfu fushi 經略安撫副使) Fan Zhongyan 范仲淹 (989-1052), who regarded Zhang Zai highly for his knowledge of Confucian principles, and urged Zhang to leave military service to study more intensively canonic texts like the book Zhongyong 中庸. Yet Zhang was not impressed by this text and began to study Buddhist and Daoist teachings and other writings of the "hundred masters", as well as books on natural science and medicine. These studies convinced him that Buddhism and Daoism were insufficient in explaining the relation between nature and social relations, and therefore returned to Confucian studies, and initiated the discourse on the relation between matter and moral ethics.
One might say the the cosmology of the Classic Yijing 易經 "Book of Changes" was the guide-rope, the Zhongyong text the corpus of his philosophy, the ritual classics its adaption, and the teachings of Confucius (Kongzi 孔子, 551-479 BCE) and Meng Ke 孟軻 (Mengzi, 385-304 or 372-289) the methodology. His commentary Mengzi jie 孟子解 is lost.
Zhang's fundamental theories are assembled in his book Zhengmeng 正蒙 "The right clarification". With concepts of the Yijing commentaries, Zhang explains that the universe was based on the shapeless "great void" (taixu 太虛) that was filled with formless matter (qi 氣), out of which the ten thousand beings gained shape by the agglomeration of matter and the exchange of the "energies" or potentials of Yin and Yang 陰陽, leading to a kind of dualism in each single object and being (yi wu liang ti 一物兩體 “two physics in one object”). These objects might, following a temporal circle, disintegrate into elements of matter, and return to shaplessness.
Humans were made of the same stuff as objects, and could therefore be called children of Heaven and Earth, and all men could be regarded as siblings, and the animate and inanimate nature as companions. The sovereign was the oldest brother of all men. In his book Ximing 西銘 "Western inscription", Zhang Zai thus went beyond the traditional view of kinship by blood and ancestry – even beyond the view of Confucius, and claimed that moral duties like kindness and righteousness were not just used with respect to kinspeople, but towards every human person as members of one great family. Zhang was convinced that all men and even men and objects were cognates (min bao wu yu 民胞物與), and thus bound by feelings surpassing the traditional social order of Confucianism.
His intensive studies of Buddhism and Daoism made Zhang Zai one of the most vehement critics of the time. The Daoist belief that matter came out of of veritable voidness, or the Buddhist view that all objects were just illusion of the mind and could terminate in nirvana was unsubstantiated in Zhang's view. The Buddist concept of inherited karma (yinyuan 因緣) was too vague in his eyes to converge with the natural principles of Heaven (tiandao 天道) given to man by way of the substance of his body.
The duty of a superior man (daren 大人, junzi 君子, shengren 聖人) was to find out the universal "Heavenly principle" (tianli 天理) in substance. This was possible because all objects, creatures, men, and their activites were equipped with this principle in the form of a naturally "good character" of Heaven and Earth – "everying is good by nature" (wu bu shan 無不善). Yet the original character of Heaven and Earth (tiandi zhi xing 天地之性) was obscured if objects and beings took shape, and the character of substance (qizhi zhi xing 氣質之性) was therefore somehow tainted. The human body and its organs acquired the character of objects (gong qu zhi xing 攻取之性), but might not be able in this way to grasp the Heavenly principle. Knowledge about the virtues embedded in the natural character could originate in sensual impressions. Only by studying and keeping perfectly to rites, etiquette and propriety, this natural character would perfectly come to light (zhi li cheng xing 知禮成性). Whoever wished to enlighten sincerity out of himself (zi ming cheng 自明誠) would first have to found out about the nature of the universal principle (xian qiong li 先窮理) before he would fully understand its character (zhi yu jin xing 至于盡性). The right way was to give up selfish desires (renyu 人欲) and self-centered thoughts (wu wo 無我 "not know oneself") and see oneself part of a great unified world were all objects were joined by a great universal mind (da xin ti wu 大心體物). The superior man would store this spirit in his own heart and continue along the transformations of the world (cun shen shun hua 存神順化). The ideal of human activities was to bring profit to others (li yi min 利于民). Zhang Zai defined this mode of "profit" (li 利) as in accordance with the righteousness (yi 義) of Heaven and Earth, while selfish profits or profits for the state could not be called "profit" in this sense (jie fei li ye 皆非利也).
With regard to the study of the classical texts, Zhang Zai stressed the importance of "comprehension within the heart" (xin jie 心解) or "enlightenment of the heart" (xin wu 心悟). This enlightenment was to come from within oneself, and as soon as the "principles of righteousness" (yili 義理) were understood, man had clear objectives and could live in peace. Any doubt made the discarding of old views necessary and their replacement by new views.
The ritual classic Zhouli 周禮 was of great interest for practical application in the eyes of Zhang Zai. In his lectures, he dreamt of reintroducing the ancient well-field system with its fair distribution (junping 均平) of landed property, and particularly purchased land to test it in practice.
Zhang's studies of the books Lunyu 論語 "Confucian Analects" and Mengzi 孟子 "Master Meng" initiated the intellectual turn from the Five Classics (Wujing 五經) to the Four Books (Sishu 四書), which became the canon of Neo-Confucian philosophers.
The teacher Zhang Zai saw the role of eduction as something to transform human "substance" to perfect morality. In order to achieve this, education had to start as early as possible. Another precondition was a strong will while would lead to great talents and great works (shiye 事業). Such persons could be expected to "become great" (ke da 可大) and "possess fortune" (fuyou 富有). A long-lasting will corresponded to long-lasting substance, and enduring moral character (de xing 德性) that brought about novel spirits day by day (ri xin 日新). A good teacher had to use all his talents (jin qi cai 盡其材), keep to the right order (xun qi xu 循其序) of easy things first and difficult ones later, meeting the right moment and occasion (dang qi ke 當其可), and develop answers out of questions (zhong qifa 重啟發).
Apart from the books Zhengmeng and Ximing, Zhang Zai wrote a commentary called Hengqu Yishuo 橫渠易說 and the theoretical text Jingxue liku 經學理窟. His collected writings are called Zhangzi quanshu 張子全書, edited by Shen Zizhang 沈自彰 (jinshi degree 1601), or – in a modern version – Zhang Zai ji 張載集. The discourses of Zhang Zai with his disciples are found in the compilation Zhangzi yulu 張子語錄.