This book provides a theoretical framework for explaining the choices made by international decision-makers in terms of what constitutes law. It comprehensively analyzes the practice of human rights courts in applying legal instruments outside their competence and proposes that this practice recognizes that different normative instruments coexist in an un-ordered space, and that meaning can be produced by the free interaction of those instruments around a problem. Based on this, the book advances its normative plurality hypothesis, which states that decision-makers must survey the acquis...