Arguments on anti-heterodoxy of Kim Pyung-mook was based on the dichotomous logical structure of Sino-barbarian theory, the Neo-confucian culturalism. His thought was deeply rooted in the cultural supremacy that Chosun, Korea inherited uniquely the cultural orthodoxy of Ming, China. Therefore, he insistently asserted that neither Catholicism nor scientific technologies including astronomy and military weapons introduced from the West were worthy of embracing. He thought that ‘defending orthodoxy and rejecting heterodoxy(衛正斥邪)’and ‘stabilizing the government and strengthening the national defense(內修外攘)’amounted to the natural principle to have to be kept by saints and virtuous gentlemen, and so that all the other fields of study except Neo-confucianism must not be useful at all. His extremly exclusive attitude to the Western studies and henceforth the politically strong power of execution were originated in the internal and external circumstances surrounding Chosun at that time. Early 19th century, Chosun was pervaded by harm effects of restricted ruling clans, and western warships and merchant ships appeared frequently at rivers and coasts of Chosun. As a result, western merchan-dises were traded and western Catholic missionaries infiltrated into Chosun and in Chosun devotees spread through the country. In Qing, China, military aggression by western powers was accelerated. Under such internal and external circumstances surrounding Chosun at that time, when both in and out of government, perception of crisis was mounting, Lee Hang-ro and Kim Pyung-mook, No-ron faction out of political power, had to search for their own political line. In the course, they showed such extreme ideological tendency and political movement, where intention to grasp the political initiative may be at work.