흄, 칸트의 존재ㆍ당위 이원론과 자연법비판 문제

This article aims to examine the Is-Ought dualism of David Hume and Immanuel Kant, and its critics of natural law theory. According to a well-known story in the legal academy, Hume and Kant have brought about an epistemological crisis in natural law theory by strictly distinguishing Is from Ought and proving we cannot derive Ought from Is. This paper argues that neither Kant nor Hume had argued such dualism and that the well-known story is only a slogan manipulated by Gustave Radbruch and Hans Kelsen to criticize the whole natural law theory tradition. Interpretations of Hume's views failed to reach an agreement on the question whether Hume raised the issue of the Is-Ought Question in his A Treatise of Human Nature. Traditional interpretation views that Hume argued for Is-Ought dualism, but recent interpretations believe that Hume intended to say something completely different in the context of the paragraph. In addition, contrary to the well-known story, this paper argues Hume and Kant criticized the natural law theories of their time and reconstructed the natural law theory in their way. Hume opened the way to reinterpreting the traditional theories of natural law by presenting emotions, not reason, as human nature. Kant contributed to the history of natural law theory by constructing metaphysical natural law theory. In addition, regarding Radbruch's criticism of natural law, this article pointed out that his arguments lack consistency, such as committing internal contradictions. As for Kelsen’s natural law criticism, this article pointed out that even if he followed Kant’s tradition, his arguments could not be a sound criticism because of failing to give an accurate definition of Is and Ought.