While Confucian influence had arrived earlier, it only displaced Buddhism as the ruling religious philosophy of Korea during the Choson dynasty (1392-1910). Entering initially as Chinese neo-Confucianism as formulated by Chu His (Zhi Xi), Korea would gradually become the isolated Hermit Kingdom that kept itself separate from outside influences, especially after suffering defeats in wars with Manchuria and Japan around 1600 that resulted in much destruction within Korea. Its ruling yangban elite gradually developed their own version of neo-Confucianism, although it is a curious fact that some of the larger changes would come from occasional interjections of outside influence from time to time (Deuchler, 1992; Cumings, 1997; Kleiner, 2001; Chung, 2006; Song, 2010), although in the early days of the dynasty it was open and a world technological leader in such areas as printing and armored ships.
One of the most important periods in the development of a distinctive Korean neo-Confucianism was the Sirhak (or Silhak) movement, usually translated as “practical learning.” This reflected influences coming from China, the one nation that Korea maintained some connection with as it became increasingly isolated, with the initial introduction after 1600 coming after Yi Su-kwang visited Beijing. It viewed itself as critical of the established neo-Confucianism of that time, with Korean military defeats making an opening for some reforms. Curiously, one of the more important parts of this influence involved Christianity,11 particularly Catholicism, which had gained a foothold in China due to Jesuit missionaries, although they would eventually be expelled. Only a few actual Europeans entered Korea to spread this influence, with more of it coming from Koreans who visited China or Catholic-influenced Chinese visiting Korea. Among the ideas this Catholic influence introduced was an emphasis on personal well-being and justice.
The figure often seen as codifying a late Choson form of Korean neo-Confucianism incorporating these Sirhak influences was Chong Yak-Yong (1762-1836), known by his pen name, Tasan (Chung, 1995). He focused on the “three bonds,”: son to father, subject to king, wife to husband, and reasserted the “five moral relationships”: affection between father and son, proper order of old and young, righteousness between king and subject, proper separation of functions between husband and wife, and faithfulness among friends, with all of these based on the Confucian harmony of jen (Deuchler, 1992). While initially focusing on practicality and fairness, this assimilation of Sirhak ideas after Tasan became the especially ossified version of Korean neo-Confucianism wielded by the yangban elite to dominate an increasingly economically backward and stagnant Hermit Kingdom as the 1800s proceeded.
This ossified Korean neo-Confucianism, which inculcated the worst of the economy-stalling anti-mercantilism and isolationism, would face a new challenge with the Tonghak movement begun by Ch’oe Cheu, who was martyred in 1864, but whose followers expanded in number after that to lead a full-scale uprising in the 1894 that would trigger the beginning of the end of the Choson dynasty (Kallander, 2013). Like the Sirhak movement, this one also drew heavily on outside Christian influences, as well as long-suppressed Buddhist and Sinkyo influences, and more strongly emphasized justice and peasant rights, fundamentally asserting the unity of the human and the divine that asserted the dignity of individual people regardless of their socio-economic status. But it would not be assimilated into the existing Confucian doctrine or system. The rebellion was so severe that the Korean government led by the yangban elite called upon the Chinese government to intervene to help put down the rebellion. The Chinese did send in soldiers to assist, however, the Japanese also did so uninvited. Their forces clashed, setting off the 1894-1895 Sino-Japanese War that the Japanese won, with Taiwan and other territories coming under Japanese rule at that time, although not Korea itself until 1910. In any case, the Tonghaks were successfully suppressed, although some of their ideas about peasant uprisings would be picked up later by the North Koreans, and it has been viewed more broadly in both Koreas as an important inspiration for Korean nationalism (Chong, 1969). Their remnant formally became the eclectic Ch’ŏndogyo religion in 1905, which not only persists in South Korea but is apparently experiencing a new popularity with as many as three million followers recently.
With the conquest of Korea by Japan in 1910 and their subsequent rule until 1945, Korean Confucianism in effect went underground, replaced as a ruling ideology by its Japanese cousin discussed above, with a Shinto overlay. This would damage Confucianism in the eyes of many Koreans for its inability to withstand the Japanese invaders, while ironically the Japanese rule in many ways continued and even reinforced the traditional Confucianism of Korean society. When the Japanese were overthrown and expelled in 1945, there would be a strong revulsion against Confucianism on both of these grounds, its identification with a weak feudalism that could not defend itself against Japan,12 and also its identification with the hated Japanese rulers. But part of this official revulsion, which would continue in both the North and the South, also reflected how strongly entrenched that influence was in Korea, the land that in the late 19th century had been “at times even more Confucian and traditionally Chinese than China itself” (Reischauer and Fairbank, 1960,. P. 426).