Yan Yuan 顔元 (1635-1704), courtesy name Hunran 渾然 or Yizhi 易直, style Xizhai 習齋, was an early Qing period 清 (1644-1911) philosopher. He hailed from Boye 博野, Zhili (Hebei) and was one of the founders of the Yan-Li School 顏李學派 of philosophy - the other was Li Gong 李塨 (1659-1733). Yan obtained the xiucai grade at the age of nineteen sui, but soon decided to become a private teacher (see schools) instead of pursuing an offical career. During the Kangxi reign 康熙 (r. 1661-1722), Li Gong enrolled in Yan Yuan's school and became his most important disciple.
In his earlier years, Yan Yuan obtained instruction in Daoist methods of prolonging life, and was also educated according to the propositions of the Neo-Confucians Lu Jiuyuan 陸九淵 (1139-1193), Wang Yangming 王陽明 (xinxue 心學), the brothers Cheng Hao 程顥 (1032-1085), Cheng Yi 程顥 (1032-1085) and Zhu Xi 朱熹 (1130-1200). When his mother died, for instance, he expressed his mourning according to the Family Rites of Zhu Xi (Zhuzi jiali 朱子家禮) and refused to eat and to drink. He became so sick that he nearly died.
This experience demonstrated that the ritual laws of the Neo-Confucians were too strict, and even harmful, to the body. Yan Yuan therefore went over to a more realistic interpretation of the world, with "practical writings, practical activities, practical implementations, and practical use" (shiwen, shixing, shiti, shiyong 實文,實行,實體,實用), and criticized the Neo-Confucian doctrine of "quietly sitting" and studying books, and to nourish one's character by preserving the mind. He constated that with such void teachings it would be impossible that the Heavenly principle (li 理) would be found anywhere outside the own mind (xin 心) and character (xing 性), and scorned Zhu Xi's teachings as "a mouthful of nonsense" (mankou hushuo 滿口胡說). The exclusive studies of books would produce a race of week, sick and useless people, a result that was in fact contrary to the image of man that Confucius and Mengzi 孟子 had created.
It was the duty of the Confucian scholar, he said, to enlighten the "six virtues" (liude 六德) and "six conducts" (liuxing 六行) of the ancient sages Yao 堯, Shun 舜, King Wen of Zhou 周文王, and Confucius. The method of enlightening the Great Way of the saints was not to study ancient writings, just like learning was not really perfected by reading old books, but by finding out how Confucius and his disciples had lived according to moral principles that they practiced each day for their whole life. Yan Yuan stressed that it was highly important to learn and to train the "six arts" (liuyi 六藝), but also applied techniques like warfare, agriculture, the crafts, monetary matters, and hydrology.
Concerning the human character, Yan Yuan criticized the Neo-Confucian concept of the Heaven-bestowed character and the relation between character and substance. Instead, he followed Mengzi's theorem of the goodness of human nature by itself, and not as a result of a Heavenly principle, substance or physical shape. Any evil behaviour was the result of a "contamination" by social circumstances, and not part of human nature. Character (xing 性), emotion (qing 情) and talent (cai 才) were parts of one and the same person and could not be separated. With regard to the relation between righteousness (yi 義) and profit (li 利) he transformed an old saying of the Han period 漢 (206 BCE-220 CE) philosopher Dong Zhongshu 董仲舒 (179-104 BCE) to the statement that one had to "rectify one's righteousness to calculate for benefits, and to enlighten one's way to plan for merits" (zheng qi yi yi mou qi li, ming qi dao er ji qi gong 正其誼以謀其利，明其道而計其功".
Yan Yuan was of the opinion that the well-field system (jingtian 井田) according to the "way of the kings" (wangdao 王道) of ancient times was the best economical unit, but he also admitted that only the opening of new fields, an equal allotment of land, and hydrology would make a country prosperous.
The most important writings of Yan Yuan are Sicunbian 四存編 (in four parts: Cunxingbian 存性編 "On the preservation of the character", Cunxuebian 存學編 "On the preservation of the teachings", Cunzhibian 存治編 "On the preservation of the government", and Cunrenbian 存人編 "On the preservation of humaneness"), Sishu zhengwu 四書正誤, Zhuzu yulei 朱子語類評, Liwen shouchao 禮文手抄.