Constitutionalising Secession proceeds from the question, ”What, if anything, does the law have to say about a secession crisis?” But rather than approaching secession through the optic of political or nationalist institutional accommodation, this book focuses on the underpinnings to a constitutional order as a law-making community, underpinnings laid bare by secession pressures. Relying on the corrosive effects of secession, it explores the deep structure of a constitutional order and the motive forces creating and sustaining that order. A core idea is that the normativity of law is best understood, through a constitutional optic, as an integrative, associative force. Constitutionalising Secession critically analyses conceptions of constitutional order implicit in the leading models of secession, and takes as a leading case-study the judicial and legislative response to secession in Canada. The book therefore develops a concept of constitutionalism and law-making – ”associative constitutionalism” – to describe their deep structure as a continuing, integrative process of association. This model of a dynamic process of value formation can address both the association and the disassociation of constitutional systems.