This dissertation is an exploration of the ways in which contemporary practices of pluralism are challenging, and being shaped by, concepts of state sovereignty. I explore two very different contexts; the relationship between First Nations and Settlers on that part of Turtle Island sometimes called Canada, and the relationship between the European Union and its Member-States. In both contexts, I explore how political, legal, and economic practices are generating forms of social order that depart to varying degrees from the total, exclusive authority associated with sovereignty. In particular, I show that actors in both settings have actually developed two remarkably similar practices – interpenetrating institutions or co-decision mechanisms, and conditional authority claims. Together, these practices enable actors to contest and coordinate their respective authority claims in ways that do not rely on an overarching sovereign or even a shared understanding of their relationship. Instead, practices of interpenetration and conditional authority make all parties responsive to multiple standards of conduct, allowing diverse actors to seek justice over time in conditions of persistent difference and conflict. / Graduate