Introduction of Western International Law into East Asia - Mergence or Conflict and Substitution: YU Kil-chun's Argument of the Yangjul (Twice Folded) System

When international law of Western origin was introduced into East Asia, conflict with the Sinocentric order, which already existed there, was a more conspicuous feature than mergence. For Korea, this conflict raised the problem of her legal status under international law, as Korea had been a tributary state to China under the Sinocentric order and this fact might have been reflected to the eyes of international law as vassalage. This problem of re-comprehension of the status of Korea in the framework of international law had a very practical significance, because Korea might or might not conclude treaties with Western states, send and receive diplomatic missions to the Western states and owe responsibility for the legal problems that occurred between Korea and Western states according to the answer to this question. YU Kil-chun’s theory of the ‘Yangjul System’ (Twice Folded System) was a response by a Korean intellectual to this problem. The theory, suggested in Chapter 3 of ‘Seoyugyenmun’ (Observations on Travels in the West), argues that both Korea and China were under two different normative systems. According to one system, the Sinocentric System, Korea was a tributary state to China. However, this could not affect the sovereign and independent status of Korea under another system, the system of international law. Therefore, Korea was a state with full fledged rights bestowed by international law. This was what YU tried to demonstrate in his book using the concept of ‘Yangjul’, a concept which is called a intuition of genius. This concept is a theoretical concept as it conceptualizes the unique state of the relationship between Korea and China under the two competing and conflicting orders of Sinocentrism and international law. At the same time, it is a practical concept as it is a concept invented to contribute to demonstrating Korean sovereignty and independence. It is a descriptive concept as it states that the relation between Chosun and Qing was an unequal one as the former had paid tribute to the latter. However it is also a concept of prescription as it asserts that the legal status of Chosun under international law should not be misunderstood as vassalage. It is both a theoretical and a practical concept and both a descriptive and a prescriptive concept. In this sense it in itself is a twice folded concept.