ki becomes emanant, i ‘rides’ ki. Though he was critical of Toegye's idea that ki follows i as being dualistic, Yulgok (Yi I, 1536 – 84 ) nevertheless embraced his notion that i ‘rides’ ki: only ki is emanant and i moves its emanation; i and ki are ‘neither two things nor one thing’, as evidenced by ‘wondrous fusion’ (myohap). For Yulgok, original nature (i) and physical nature (ki) coalesce into one human nature. Toegye and Yulgok, whose thoughts culminated in an irenic fusionism, constituted the crowning phase of East Asian neo-Confucianism by exhibiting dialectical dexterity in articulating the concepts of i and ki, left unclarified by the Chinese. Toegye also developed the neo-Confucianist concept of single-mindedness (kyung), which was a manifestation of his unequivocal humanism, as shown by his total rejection of the Mandate of Heaven (chunmyung), which still had a hold on the Chinese, including Chu Hsi. Toegye's kyung synthesized the primeval Korean sense of supreme-efforts-come-earnest-devotion (chisung) with the Confucianist notion of holding fast to mind (jik-yung); he advocated self-efforts for creating a meaningful life. In particular, his concept of single-mindedness had a lasting influence on the Japanese neo-Confucianists of the Tokugawa period. Every major Korean neo-Confucianist shared Toegye's preoccupation with single-mindedness, which signalled new stress on praxis in the development of Korean neo-Confucianism: the fusion of the metaphysical and the physical is better brought about through action than speculation, important as theory might be. That was the point of Yulgok's integration of sincerity (sung) with single-mindedness. In this respect Korean neo-Confucianism made a break with the Cheng-Chu school of Chinese neo-Confucianism, which was overly speculative. Silhak During the later Joseon period, Silhak, a form of Neo-Confucianism, emerged. One of the most prominent Silhak philosophers was Jeong Yakyong. Seohak Donghak Korea in 1890–1945 Western philosophy Those who were sent to be educated in Japan, returned with limited knowledge of Western philosophy as a whole, although the German educational influence in Japan led to the beginning of interest in German idealists in Korea through indirect knowledge, with the exception of Marx, Hegel, and the dialecticians. Christianity The strong influence of low church Christianity, through missionary schools, led to practical American YMCA-style philosophy entering into Korea from the 1890s onwards. The discussion of Korean Christianity and Korean Christian philosophy is complicated with many divisions, and discussed in articles elsewhere. North Korea South Korea Western philosophy South Korea was mostly under