The "Teachings of the Heart" or the human mind (xinxue 心學) was the lesser one of the two great Neo-Confucian schools. Lu Jiuyuan 陸九淵 (1139-1193) is usually regarded as its founder, while Wang Shouren 王守仁 (Wang Yangming 王陽明, 1472-1529) was one of the few important adherents of it during the Ming period 明 (1368-1644). For this reason, the schools is also known as Lu-Wang xinxue 陸王心學, in contrast to the Cheng-Zhu lixue 程朱理學, the "teachings of the universal principle" that were founded by the brothers Cheng Hao 程顥 (1032-1085) and Cheng Yi 程頤 (1033-1107) and refined by Zhu Xi 朱熹 (1130-1200). Lu Jiuyuan's teachings were refered to as Nansong Luxue 南宋陸學.
The idea of the heart as a place where the prefect man was able to understand human relationships and the intentions of Heaven was the book Mengzi 孟子. The book explains (ch. Jinxin A 盡心上) that the perfect man (junzi 君子) or great man (da zhangfu 大丈夫) "exhausted all mental constitution" (jin qi xin 盡其心) to understand his nature (zhi qi xing 知其性). Knowing his nature, he knew Heaven (zhi tian 知天). In consequence, the perfect man would not be dissipated by wealth and power, not be swerved by poverty and meanness, and not be bend by force and power (ch. Teng Wengong B 滕文公下). In the Lunyu 論語 "Confucian Analects", Confucius' (Kongzi 孔子, 551-479 BCE) disciple Zengzi 曾子 (505-436) is the person whose thoughts are engaged most with the human heart or mind.
As other Neo-Confucian scholars, Lu Jiuyuan was convinced that there was one principle which held the cosmos together and was inherently embedded in all objects and living beings. The "ten thousand beings" (wanwu 萬物) were tied together (tongyi 統一) by this principle. This concept is similar to Daoism, a philosophy seeing the Way (dao 道) and the basic and universal principle. For this reason, Neo-Confucianism is also called daoxue 道學 "Teachings of the Way", even if the more widespread term for the universal principle is li 理 or tianli 天理, literally "Heavenly order" or "structure". Lu Jiuyuan identified the human heart or mind (xin 心) as the place there the universal principle was found in human beings.
Yet while Daoists attributed to the Way a neutral and "natural" (ziran 自然) character, the Neo-Confucians held that the universal principle determined social hierarchies and the goodness of man (ren shan 人善), expressed in the five Confucian virtues (wuchang 五常) kindheartedness (ren 仁), righteousness (yi 義), rites (li 禮), wisdom (zhi 智), and trust (xin 信). Lu Jiuyuan's way to find out about these modes of conduct was "to search the truth by contemplation" (shen si qiu shi 深思求實), as Zengzi had proposed, and not following the cultivation of behavior by practice, as Confucius' disciple Ziyou 子有 (522-489) had preferred. Lu Jiuyuan even used a term from the Daoist book Zhuangzi 莊子 (ch. Ren jian shi 人間世), namely xin zhai 心齋 "fasting of the mind", laid into the mouth of Confucius, who urged not to wait for the hearing of the ears, but to trust into the "hearing of the mind" (ting zhi yi xin 聽之以心).
By the hearing of the mind, every sacred man (shengren 聖人) would be able to understand the meaning of the universal principle. It was the same for everyone and through space and time because the heart of every human being was identical, and each heart or mind was equipped with the universal principle, which means that each and every heart or mind was identical to the universal principle (ren jie you shi xin, xin jie ju shi li, xin ji li ye 人皆有是心，心皆具是理，心即理也). This kind of practice is similar to the "self-divinization techniques" (Puett 2004: 24) of Daoism.
In this way, the human mind was not an individual and subjective matter because it was derived from the universal principle, which was a general and objective matter. The search for the universal principle was an easy task (jianyi gongfu 簡易功夫) because it became apparent in one's heart (fa ming ben xin 發明本心) in search for the lost mind (qiu qi fang xin 求其放心). Lu Jiuyuan's most important disciples were Yang Jian 楊簡 (1141-1226) and Yuan Xie 袁燮 (1144-1224). The former created the formula "the ten thousand beings are nothing else than me" (wanwu wei wo 萬物唯我).
Wang Shouren was educated according to the tenets of the dominant Neo-Confucian school, the teachings of the brothers Cheng and Zhu Xi who advocated to "investigate matters in order to perfect one's knowledge" (ge wu zhi zhi 格物致知). According to a famous story, Wang tried to perfect his knowledge about the universal principle with the help of a bamboo stalk, but when he found he was unable to do so, he turned to the teachings of Lu Jiuyuan which he found much more applicable. Wang even went so far to interpret the existence of the ten thousand beings, including Heaven, earth, spirits and humans, as inseparable from one's heart. Having left one's mind, they did not exist (lique wo de lingming, bian mei you 離卻我的靈明，便沒有). He thus mixed up the physical, objective world with the ideal, subjective world in the human mind.
The mind or heart was the centre of the human body (shen zhi zhuzai bian shi xin 身之主宰便是心), and of his activities. Each action – seen as a physical thing (wu 物) – was the result of thoughts and intentions in the mind (xin zhi suo fa bian shi yi 心之所發便是意). In this way, human conduct including Confucian virtues like filialty were embedded in man's heart.
In his idealist interpretation, Wang Shouren deviated from Zhu Xi's proposition that things per se included the universal principle (zai wu wei li 在物為理). Wang held that only when the human mind produced thoughts about something, it was endowed with the universal principle (xin zai wu ze li 心在物為理) because if things could not exist without being bound to the human heart or mind (wanshi wanwu zhi li, bu wai yu wu xin 萬事萬物之理，不外于吾心), how could they be endowed with any universal principle. Zhu Xi's approach to engage in objects to study thoroughly the universal principle within them (ji wu qiong li 即物窮理) was therefore not possible in Wang's eyes. Filial piety, for instance, was in the son's heart, and not in the person of the father. The universal principle could not be found in the father (particularly not after his passing away), but in the son's own heart (xiao zhi li zai yu wu zhi xin 孝之理在于吾之心). Outside of the human heart, no objects did exist, nor actions, nor the universal principle, nor righteousness, nor moral goodness.
Because the universal principle was endowed in everyone's heart and mind, every person was in possession of innate knowledge (liang zhi 良知) about the Heavenly principle and the moral question of right and wrong. In consequence, knowledge and action were unified (zhi xing he yi 知行合一) as a continuous duality. This was in contrast to the mainstream Neo-Confucians who requested that knowledge must be acquired before action could take place (zhi xian xing hou 知先行後).
The most important disciple of Wang Shouren was Wang Gen 王艮 (1483-1541). Because everyone was able to perceive the universal principle in his own heart, Wang Gen proposed that every person had the potential to become a "saint" (shengren) or wise man (xianren 賢人).
Even if the teaching of the mind was a minor trend among philosophers, the attacks of Lu Jiuyuan and Wang Yangming on the prevailing mode of Neo-Confucianism yielded results in the requests of some scholars to deviate from the wording of the "Confucian Analects", or even to suspect the rightfulness of imperial edicts. Li Zhi 李贄 (1527-1602) urged not to follow each "right and wrong" of Confucius, and even doubted that it was possible to tell what was right and wrong (shi fei wu ding zhi 是非無定質).
Huang Zongxi 黃宗羲 (1610-1695) criticized the strict obedience to the Son of Heaven, but on the other hand strictly criticized the arbitrariness of Wang Gen, Yan Jun 顏鈞 (1504-1596) and He Xinyin 何心隱 (1517-1579). Traces of Lu's individualist thought are found in the critical writings of the reformist thinker Tan Sitong 譚嗣同 (1865-1898). Wang Shouren's philosophy influenced the Japanese thinkers Nakae Tōju 中江藤樹 (1608-1648) and Satō Issai 佐藤一斎 (1772-1859).
The Republican philosopher He Lin 賀麟 (1902-1992) is seen as the founder of "New Idealism" (xin xinxue 新心學). He re-interpreted Wang Shouren's distinction between mind/heart and objects in a Hegelian way and defined the mind/heart as the place where objects had their virtual body or substance (xin wei wu zhi ti 心為物之體), while objects themselves were the substantial application or expression of the mind (wu wei xin zhi yong 物為心之用).
On the other hand, the individualist aspect of Wang's teachings brought about the belief that everyone was able to acquire knowledge without experience and without practical work, as could be seen during the Great Leap Forward and the Cultural Revolution.