韓元震（1682-1751）由「氣」見「理」，以「氣」論「心」，立場鮮明，為栗谷學派後起健將，與同門李柬（1677-1727）針對「人物性同異」問題，產生相異的見解，往復辯論，形成朝鮮後期一場重要的學術論爭，稱為「湖洛論爭」或是「湖洛是非」。事實上，韓氏撰有《朱子言論同異考》，全書六卷，共計三十九門，並附以《論孟輯註或問》，由義理而及於經解，乃至於史傳文字等，朱熹學術無不涉及，牽涉既廣，體系龐大，本文以《四書》為範圍，考察韓元震於朱熹書信、語錄、經解文字當中，分析相歧說法，以定朱熹學術究竟。韓氏推斷細密，成果斐然，細節之間，得見朱熹反覆錘鍊，一生思索的歷程，終於在後人以朱證朱的詮釋方式當中，甚至援朱以附陸的情況下，引導回歸於朱熹學術思考正途，在理學、心學之分，漢學、宋學之辨，門戶歧出之中，具有平抑作用，不僅樹立朝鮮朱學主體意義，對於朱學更有推進作用。

Han Yuanzhen (1682-1751), an outstanding scholar of Ligu School, learns ＂principle (li)＂ from ＂material-force (qi),＂ and discusses ＂mind (xin)＂ based on ＂principle.＂ He has a clear theoretical standpoint, his argument with his fellow, Li Jian (1677-1727), is recorded in ＂Sameness or Differences between Human Nature and Animal Nature.＂ Their arguments are known as Huluo Debate, an important academic discussion in Korea. Through his studies on Confucianism, annotations of classics and historical texts, Han composes Survey on the Sameness and Differences of Zhu Xi's Discourses (Zhuzi yanlun tongyikao). There are six volumes and thirty-nine categories in this book, which also includes Questions on Annotations of Analects of Confucius and Mencius (Lunmeng jizhu huowen). Since the doctrine of Zhu Xi covers an extensive range of knowledge, in this paper I mainly focus on the Four Books in order to analyze how Han Yuanzhen discusses Zhu Xi through Zhu's letters, dicta, and annotations on classics. Zhu Xi's academic achievement and lifelong thinking process will be further clarified through the studies of Han, who examines Zhu's ideas with Zhu's own texts, and even quotes Zhu's words to comparewith Lu Jiuyuan's texts. These studies help readers to understand more about Zhu Xi's thoughts among studies which distinguish between Philosophy of Principle (lixue) and Philosophy of Mind (xinxue), as well as Han School and Song School. And this further establishes the studies of Zhu Xi in Korea.