Xue Xuan 薛瑄 (1389-1464), courtesy name Xue Dewen 薛德溫, style Jingxuan 敬軒, was a Confucian scholar of the early Ming period 明 (1368-1644). He came from Hejin 河津, Shanxi 山西, and was investigating censor (jiancha yushi 監察御史), assistant superintendent of training (tixue qianshi 提學僉事) of Shandong, Minister of the Court of Judicial Review (dalisi zhengqing 大理寺正卿), and during the Jingtai reign 景泰 (1450-1456) he was transferred to the some post, but in the southern capital Nanjing 南京. Finally he rose to the office of Right Vice Minister of Rites (libu you shilang 禮部右侍郎). In his later years he retired and became a private teacher. His philosophy was influenced by Neo-Confucian thought. The aim of all philosophy was, he said, to "return to one's own character" (fuxing 復性). This was important because, according to the brothers Cheng Hao 程顥 and Cheng Yi 程頤 and the great Southern Song period 南宋 (1127-1279) master Zhu Xi 朱熹 (1130-1200), the human character was identical to the Heavenly principle (xing ji li 性即理). Xue Xuan expanded this view in the theorem that the whole world could be resumed in one word: character. Unlike substance that concentrates and diverges, the Heavenly principle is always in the same "aggregate state" (li wu ju san 理無聚散 "the principle does not coagulate or dissipate"). He also corrected the opinion of Zhu Xi that the principle was existing before matter and substance came into being. The principle was tied to substance and could not be separated from it. "Under Heaven", Xue Xuan said, "there is no principle without matter" (wu wu qi zhi li 無無氣之理), and no matter without that the Heavenly principle is embedded. Xue Xuan explained that it was the duty of the righteous man to "return to his own character" (fu xing 復性), similar to Confucius' precept to "give up the self and return to propriety" (ke ji fu li 克己復禮). It was necessary to be "controlled by reverence" (zhu jing 主敬), and to "hold up reverence" (chi jing 持敬); to study in the lower parts of consciousness, and to extend to the upper parts of it; and to cultivate one's inner parts and external behaviour.
Xue Xuan's most important writings are Dushulu 讀書錄 and Dushu xulu 讀書續錄. His collected writings are called Xue Wenqinggong wenji 薛文清公文集.