The Boundary Between Legislation and Adjudication: The Limits of Legal Interpretation

What is the relationship between legislation and adjudication? Traditionally, it is believed that judges should simply apply the law to specific facts and render judgments accordingly. Montesquieu encapsulated this view by describing judges as "the mouthpieces of the law." In contrast, the Free Law Movement posits that judges are not strictly bound by the text of the law and have the freedom to discover or even create law as needed. Between these two extremes, there exists a range of perspectives on the relationship between legislative and judicial powers. This relationship is crucial because it defines the limits of legal interpretation, making it a central issue in judicial decision-making. This paper begins by exploring the objectives and methods of legal interpretation. It then examines how the Supreme Court of Korea, particularly through its en banc decisions, navigates the relationship between legislation and judicial precedent, or between legislative theory and interpretive theory. The Supreme Court cases discussed in this paper — covering topics such as the gender correction for transgender individuals, parental status of children born through artificial insemination, nominee trusts and unconscionable legal transactions, special limited approval for minor heirs, and judicial reduction of penalty clauses — all address challenging issues that sit at the intersection of legislation and adjudication. The judiciary is vested with the authority to interpret the law, determine its meaning, define its scope, and apply it to specific cases. However, this authority is not without limits. Judges must interpret laws in a manner that respects the legislative power to create laws and must avoid distorting, altering, or replacing the legislator' s decision that can be ascertained from relevant statutory text. This approach is consistent with the constitutional principles of separation of powers and the rule of law, which delineate the distinct roles of the legislative and judicial branches. A legislator's legislative decision cannot be overturned by a judge's judicial decision. Judges must also fulfill their constitutional duty to adjudicate independently according to their conscience (Article 103 of the Constitution of Republic of Korea). It is the judge's role to ascertain the just meaning of the law, grounded in the Constitution and statutes, and to apply it to individual cases. When interpreting and applying laws, judges must confront the critical question of whether to prioritize the intent of the legislature, adhere strictly to the text of the law, or pursue the broader objectives of the law. This question forms both the starting and ending points of legal interpretation and influences views on the boundary between legislative and judicial functions. Whether there has been a legislative decision is a question of the boundaries of statutory interpretation. Legislative solutions, within the constitutional framework, offer the advantage of providing comprehensive resolutions and selecting the best option among various alternatives. However, it is not always possible or appropriate to defer to legislative solutions. The judiciary must, therefore, seek the optimal resolution within the boundaries established by the Constitution and statutes, guided by judicial conscience.