From her early days writing a book on Civil Procedure in Sweden, to her time as law professor, judge, and justice, Ruth Bader Ginsburg has always been acutely sensitive to the fact that legal systems are not hermetically sealed from each other. Always there must be ways of negotiating the interactions among such systems. In the United States, of course, such interactions often involve navigating a federalist structure of fifty-one different sovereignties, in addition to tribal governments. Internationally, the interaction of legal systems may involve the degree to which U.S. constitutional norms govern U.S. officials abroad, the impact of foreign judgments in the United States, and the potential influence of international or transnational law in domestic cases.

This chapter begins with some general observations about the reality of this legal pluralism and various possible approaches to the systemic interactions that inevitably result. Then, it surveys some of Ginsburg’s key writings on the interaction of legal systems, both in law journals and in judicial opinions. This analysis reveals a consistent theme in Ginsburg’s jurisprudence. Across a variety of substantive legal areas, Ginsburg often chooses a path that provides maximum play among the legal systems at issue. Beginning with her earliest scholarly writings, she has tended to oppose doctrines allowing one legal system to block another from adjudicating a dispute, and throughout her later career Ginsburg likewise tends to reject bright-line rules that choose one legal system over another. Instead, she often seems to prefer procedural arrangements that seek accommodation and flexibility in order to ensure that multiple legal systems and a variety of norms and processes are respected. These principles also carry over to Ginsburg’s views about international and transnational law. A committed internationalist, Ginsburg advocates the importance of seeking wisdom from others. This nondogmatic, deferential approach to plural legal systems characterizes much of her jurisprudence on intersystemic conflicts, though interestingly such deference does not always apply with as much force in Ginsburg’s opinions concerning tribal communities. By taking stock of Ginsburg’s navigation of legal pluralism in a set of representative writings, we can better theorize her contribution to a jurisprudential approach that seeks ongoing negotiation in an interlocking world of multiple jurisdictions and multiple legal norms.