The 16th century was a epoch-making time in the intellectual history of Korea because of the appearance of two greatest scholars, Nammyeong(南冥) Jo Sik(曺植) and T'oegye(退溪) Yi Hwang(李滉) who were leaders for the direction from the time forward in the intellectrual history of Korea. The difference of academic thinkings and political ideas between them clearly exposed at the beginning was one of the origins of the prosperity from 16th to 17th century in our intellectual history as their disciples were founding principal schools. On the other hand, it also brought about such serious matters as the start of confrontations and discordances between two leading schools. As Nammyeonghakpa(南冥學派) went on disorganization as a school after 17th century as well as downfall in the political world, it had been intensively under political oppression other than T'oegyehakpa(退溪學派) even in the political position similar to it within the political world. But, the negative understandings and evaluations of Nammyeonghak(南冥學) or Nammyeonghakpa in the next generation had virtually started from the discordance and conflict with T'oegye in academic thoughts and political ideas. Yi Hwang who considered as his own duty to restore the soˇngnihak(性理學) because of his awareness of the time being as a corruption conflicted undoubtedly with Nammyeong and his school, by bringing up the dispute of deviation from soˇngnihak's orthodoxy in the academic thinkings of Jo Sik made a difference with him. It also meaned the open of harsh criticism or denial against Nammyeonghak and its school. Such criticisms or negative opinions for Nammyeonghak grew in place after the severe criticisms for Chong Yinhong(鄭仁弘) who was a follower of Jo Sik. The typical critic was the Noronpa(老論派) of soyin(西人) from Yulgok(栗谷) Yi I(李珥) to Taekdang(澤堂) Yi Sik(李植). Especially Yi Sik among them tried to build the foundation of political justification by giving a criticism for Nammyeonghakpa including Chong Yinhong. Along with it, he also tried to give a harsh criticism in a full scale against Nammyeonghak through his large number of writings. After the members of Noronpa of Soyin were influenced by or followed his critical opinions, it ended up to the peak of criticism in the line of Nong'am(農巖) Kim Changhyup(金昌協) and his disciples. Kim Changhyup took a strongly critical and negative position other than Song Siyeol(宋時烈), his master, had a flexible position against Nammyeong. In the end, his negative opinions spreaded out and developed into an intensive criticism in the line of Chong'am (正庵) Yi Hyeon'ik(李顯益) who was his loyal disciple. However, in spite of the harsh journey of Nammyeonghak which had been denied even the worth for its being in history, it came to be a comeback because of its revaluation movement by the scholars of Kyeong sang Namdo(慶尙南道) province in 19th century. As it was in the 19th century of the crisis era, a group of scholars in the province started the revaluation movement of Nammyeonghak and its actual values. The movement was growing much more and continued steady to 20th century. Those flows of Nammyeonghak in the intellectual history of Korea became one of the principal reasons of understanding newly of the merit of Nammyeonghak and its reappearance. In brief, still within such continuous circumstances in crisis up to now, we started to revaluate the worth for Nammyeonghak's being as the valid thought even in our times.