On this day, 886 years ago, on March 26, 1139 (February 24, the 1139 lunar calendar), Xiangshan opened Jingshe, and Lu Jiuyuan, the founder of Ehu Lake, was born. Lu Jiuyuan (1139~1192), named Xiangshan, and the word Zijing. A famous philosopher and educator in the Southern Song Dynasty. Han nationality is from Jinxi, Fuzhou (now Jiangxi). As famous as Zhu Xi, the famous Neo-Confucianism scholar at that time, he was known as "Zhu Lu" in history. Lu Jiuyuan is the founder of China's "Mind Learning". Wang Yangming developed his theory in the Ming Dynasty and became the famous "Lu Wang School" in the history of China philosophy, which had a profound impact on Neo-Confucianism in modern China. He was later called "Lu Zi". Lu Jiuyuan was born on the second day of February of the ninth year of Shaoxing (i.e. March 26, 1139 AD). He died on the mid-day of December 14 in the winter of the fourth year of Shaoxi (i.e. January 18, 1193 AD). He was fifty-four years old. Lu Jiuyuan once built a thatched house on Longhu Mountain in Guixi to gather disciples to give lectures. Because the mountain shape was like an elephant, he called himself Xiangshan Weng, and was known as Mr. Xiangshan and Lu Xiangshan in the world. "I have lived in the mountain for five years and read its book, and more than thousands of people came to see it." In the eighth year of Qiandao (1172), he was admitted to the Jinshi. He admitted that Wang Anshi was extremely talented and unorthodox, but believed that Wang Anshi had not touched the fundamentals academically and disagreed with his political reforms. With the great righteousness of revenge and humiliation in mind for the "Jingkang Change", he visited and sought intelligent and brave people to jointly restore lost territory. When he served as a local official, he had achieved great achievements in political achievements, but he did not forget education and often taught students. After leaving Guangui, he set up a lecture hall in the academy, and all the noble and humble people came to listen to the lecture. According to the "Xiangshan Chronicle","I have never seen such a thing in the heyday of travel." He is the author of "The Complete Works of Xiangshan". In the first year of Shaoxi, Guangzong of the Southern Song Dynasty (1190), 50-year-old Lu Jiuyuan was appointed as the Jingmen Zhijun on Jinghu Road. On the third day of September of the following year, Lu Jiuyuan traveled all the way from Jiangxi to Jingmen to take office. At that time, the Jin soldiers invaded the south, and Jingmen was located on the frontier line of the Southern Song Dynasty. Lu Jiuyuan saw that Jingmen had no city walls and believed that this administrative area was located in the Jianghan Plain, with roads extending in all directions. It defended Jiangling in the south, supported Xiangyang in the north, guarded Suizhou and Zhongxiang in the east, and guarded Yichang in the west. Only when Jingmen were consolidated would the neighbors have some support, otherwise they would be attacked from both sides. Therefore, he made up his mind to build the city wall. Lu Jiuyuan boldly reformed the Jingmen Army's tax shortcomings, unreasonable system, and official stereotypes. Vendors from other places have come to Jingmen to do business, which has increased the tax revenue in Jingmen. He recommends or promotes subordinates and does not value qualifications and origins. He believes that in ancient times, since the recruitment of local officials was not limited by qualifications and origin, it was easy to distinguish between good and bad performance. Later generations cared about qualifications and origin, and it was not easy to determine whether they had political achievements. Lu Jiuyuan was honest and upright, and enforced the law impartially. When someone complained, he personally met and accepted it, regardless of whether it was morning or evening. Mediation is the main focus in resolving cases. If the content of the complaint involves privacy, violates human ethics and is indecent, the complainant is persuaded to automatically withdraw the appeal in order to maintain the integrity of social morality. Only those who commit serious crimes, serious circumstances, and who refuse to change after repeated persuasion will be punished in accordance with the law. Therefore, there are fewer and fewer civil lawsuits. By the second year of taking office, there are only two or three lawsuits filed every month. Lu Jiuyuan built a pavilion on the east slope of Xiangshan Mountain to preach Neo-Confucianism, with an audience often reaching hundreds of people. The originally isolated folk customs and humble customs in Jingmen have changed significantly. Competent departments at all levels reported Lu Jiuyuan's political achievements in Jingmen to the court. Duke Yiguo and Prime Minister Zhou Bida once emphasized that the Jingmen Army has achieved outstanding results in governance and can set an example for local officials to "practice". The glory of Lu Jiuyuan's life lies in founding a school and engaging in teaching activities. Thousands of students were educated by him. With "mind is reason" as the core, he created "mind learning", emphasizing "self-determination" and promoting the dynamic role of spirit. His theory was unique and competed with the authentic Neo-Confucianism represented by Zhu Xi at that time. In April 1145, he and Zhu Xi met at Ehu Temple in Shangrao, Jiangxi Province to discuss academic methods and attitudes. Zhu Xi holds the view of objective idealism and advocates enlightening inner knowledge through extensive reading and observation of external objects; Lu Jiuyuan holds the view of subjective idealism and believes that one should "first invent the person's true heart and then make it read". The so-called "mind is the reason", so there is no need to spend too much effort in reading and studying. Both sides wrote poems and debated. Lu accused Zhu of "splitting", and Zhu ridiculed Lu for "Zen". The academic opinions of the two schools could not be settled. This is what historians call the "Goose Lake Meeting" and the "Goose Lake Debate". Lu Xue is directly related to Mencius's "Mind Study" that "all things are prepared for me", believing that "the human heart is the spirit, and this theory is the most clear; all people have a heart, and all hearts have principles";"the universe is my heart, and my heart is the universe"; "What is in the universe is what you do, and what you do is what you do is what you do in the universe." He believed that people's hearts and principles were innate and eternal, and feudal morality such as benevolence, righteousness, courtesy, wisdom and trust were also inherent in human nature and not external. The purpose of learning is to solve this principle and fulfill this intention. It is inevitable that people will be deceived by material desires. If they are deceived, their hearts will become ineffective and the truth will become unclear. They must give lectures through teachers and friends, carefully ponder and spur themselves to restore their original nature. Cultivation lies in seeking the inner soul and deliberately nourishing the heart. The specific method is to carefully observe oneself, seek reassurance, and clarify the distinction between righteousness and benefit. Self-proclaimed this method as "simple kung fu", which is "based on its greatness","understanding the root", and "understanding the true heart". As for reading, they attach the most importance to "Da Xue","The Doctrine of the Mean","The Analects of Confucius" and "Mencius", requiring satirical and self-satisfied connection with daily things, and opposing the study of annotations and chapters and texts in order to seek benefits. The most famous students of Lu Xiangshan are Yang Jian, Yuan Xie, Shu Lin, Fu Ziyun, etc. Among them, Yang Jian further exerted his subjective idealistic world view. The Xiangshan School did not spread widely until Chen Xianzhang and Wang Shouren in the Ming Dynasty that it was re-promoted. Lu Jiuyuan's thoughts have been enriched and developed by later generations, becoming the main philosophical trend of thought since the Ming and Qing Dynasties, and have always influenced the ideological world of modern China. Famous scholars Guo Moruo and Ma Yifu both believe that they were deeply influenced by Lu Jiuyuan's thoughts. Lu Xiangshan was the founder of subjective idealism in the Song and Ming dynasties. Scholars generally believe that Lu Jiuyuan's learning is passed down from his family. However, family learning actually only created the atmosphere and conditions for the formation of this theory.