 Theories of constitutional interpretation come in a variety of forms, but they all seem, in one way or another, to ascribe importance to a number of key factors: textual or semantic meaning; political, social and legal history; intention; original understanding; and moral/political theory. The roles played by each of these factors in a theory of constitutional interpretation depend crucially on how the theorist conceives of a constitution and its role in limiting government power. Simplifying somewhat, there are two main rival views on this question. On the one side, we find theorists who view a constitution as foundational law whose principal point is to fix a long-standing framework within which legislative, executive and judicial powers are to be exercised by the various branches of government. Such theorists will tend towards interpretative theories which accord pride of place to factors like the intentions of those who created the constitution, or the original public understandings of the words chosen for inclusion in the constitution. On such a fixed view of constitutions, it is natural to think that factors like these should govern whenever they are clear and consistent. And the reason is quite straight forward. From this perspective, a constitution not only aspires to establish a framework within which government powers are to exercised, it aspires to establish one which is above, or removed from, the deep disagreements and partisan controversies encountered in ordinary, day to day law and politics. It aspires, in short, to be both stable and morally and politically neutral. To be clear, in saying that a constitution aspires, on a fixed view, to be morally and politically neutral, I in no way mean to deny that those who take this stance believe that it expresses a particular political vision or a set of fundamental commitments to certain values and principles of political morality. Quite the contrary. All constitutional theorists will agree that constitutions typically enshrine, indeed entrench, a range of moral and political commitments to values like democracy, equality, free expression, and the rule of law. But two points need to be stressed.