Abstract
In this article, we use discussion of unwritten constitutional principles in Canadian public law as a window through which to introduce interested jurists to ongoing debate over the revival of the classical legal tradition in the form of common good constitutionalism. We argue that debates over unwritten constitutional principles cannot be resolved without some recourse to the philosophical or theoretical concept of a constitution: what it is, what it does, what it is for, and whom it is for. The answers to these questions are essential for any discussion of unwritten constitutional principles. We then argue that common good constitutionalism can offer a compelling framework for understanding the purpose of constitutionalism and how to instantiate its core operative principles such as the separation of powers, the rule of law, respect for human rights, and judicial independence. However, we also stress that common good constitutionalism is emphatically a theoretical and conceptual framework and not a laundry list of positions on contested questions of institutional design. Part of its attraction will be that it gives a sound and shared principled ground -- a yardstick -- for mediating and settling such disagreements.