This paper considers the call for the integration of legal-interpretive and social science perspectives in comparative constitutional law (CCL). It argues that two features of the field complicate how we respond to this call. First, whatever the possibilities of interdisciplinary research are at an ideal level, the practical implementation of this call depends on the field’s capacity to transcend the competing views of this issue in different national research traditions. The second complicating factor is the contrasting ways in which scholars from different disciplines and regions of the world have been defining the field’s object of study. Concluding on this score that what matters is not how we define the field, but how we interact in it, the paper maps two ideal-typical models of interdisciplinary interaction – the critical engagement and benign toleration models – and explains why the former is to be preferred.
Drawing on lessons from multiple jurisdictions, the paper argues that interdisciplinarity enables critical reflection on intellectual constructs (such as metaphors and labels) used for constitutional analysis. It also triggers reflection on every discipline’s own canons and convention; exposing how canons enable as much as limit scholarly inquiry. Furthermore, it forces reflection on the manner in which we pose our research questions. When studying the ways of illiberal rulers an interdisciplinary perspective pushes comparative constitutional scholars to move beyond asking diagnostic ‘what’ and ‘how’ questions towards exploring ‘why’ and ‘what for’ questions.
This paper illustrates the possible use of empirical methods for the textual analysis of large collections of cases with the intention to contribute to a mutually fruitful interplay of empirical and hermeneutic methods. Based on a collection of ca. 400 cases of sovereign debt litigation before U.S. courts, the paper analyzes how U.S. courts take into account the public interest of the debtor state in achieving a sustainable debt burden. For this purpose, the paper focuses on the defenses raised by the debtor state and categorizes them. It turns out that these defenses change over time broadly in line with the foreign policy preferences of the U.S. government. While sovereign immunity was an important defense in the 1980s, the 1990s saw a wealth of sometimes newly-created public interest defenses. In the 2000s, defenses articulating a public interest of the debtor state become very rare. Some explanations are offered for these findings.
Beyond the discussion of empirical and hermeneutical methodology the comparison of constitutional law can be understood from a knowledge-based approach. Based on legal knowledge of a particular legal system constitutional comparison creates an inter-legal knowledge, which is per se not part of legal order, but determines a specific interrelation between different legal systems. This comparative constitutional knowledge is the result of abstraction and interrelation. It does not create legal knowledge itself, but can be used for different purposes (like theoretical conclusions or practical legal argumentation). In a pluralistic understanding comparative constitutional knowledge transforms the knowledge of different legal orders, while using a plurality of comparative methods. The latter are determined by the purpose of the comparison itself, which shall be made transparent in the overall comparison of constitutional law.