The complexity of the relationship between democracy and modern constitutionalism is revealed by treating democracy as an incomplete ideal. This refers both to the empirical incompleteness of democracy as unable to supply its own terms of application – the internal dimension – and to the normative incompleteness of democracy as guide to good government – the external dimension. Constitutionalism is a necessary response to democratic incompleteness – seeking to realize (the internal dimension) and to supplement and qualify democracy (the external dimension). How democratic incompleteness manifests itself, and how constitutionalism responds to incompleteness evolves and alters, revealing the relationship between constitutionalism and democracy as iterative. The paper concentrates on the iteration emerging from the current globalizing wave. The fact that states are no longer the exclusive sites of democratic authority compounds democratic incompleteness and complicates how constitutionalism responds. Nevertheless, the key role of constitutionalism in addressing the double incompleteness of democracy persists under globalization. This continuity reflects how the deep moral order of political modernity, in particular the emphasis on individualism, equality, collective agency and progress, remains constant while its institutional architecture, including the forms of its commitment to democracy, evolves. Constitutionalism, itself both a basic orientation and a set of design principles for that architecture, remains a necessary support for and supplement to democracy. Yet post-national constitutionalism, even more than its state-centred predecessor, remains contingent upon non-democratic considerations, so reinforcing constitutionalism’s normative and sociological vulnerability. This conclusion challenges two opposing understandings of the constitutionalism of the global age – that which indicts global constitutionalism because of its weakened democratic credentials and that which assumes that these weakened democratic credentials pose no problem for post-national constitutionalism, which may instead thrive through a heightened emphasis on non-democratic values.

This essay complements Walker’s essay with some historical and constitutional observations. It submits that Walker’s analysis is based to a large extent on reasoning derived from a particular continental European constitutional tradition. This creates certain problems of its own, that do not arise in a different constitutional tradition. This is not to say, however, that this invalidates his conclusions, but rather underpins them in an alternative manner.

This paper approaches Walker’s work from the perspective of the ubiquity of human rights language within the rhetoric of global constitutionalism. Building on Walker’s description of the relationship between constitutionalism and democracy, what I wish to suggest is that the spread of human rights discourse is intimately connected with attempts to apply constitutional discourse beyond the state. By highlighting the way in which human rights have become place-takers for political legitimacy in discussions of international constitutionalism, the paper is intended to challenge Walker to state his own position more forcefully and to develop further his insight concerning the irresolvable tension in the iterative relationship between constitutionalism and democracy.

This paper argues that Neil Walker’s analysis of the complementary relationship between democracy and constitutionalism remains one-sided. It focuses only on the incompleteness of democracy and the democracy-realizing function of constitutionalism rather than also taking into account the reverse complementary and constitution-realizing function of democracy. In this paper, I defend a fuller account that takes into account this mutual complementarity between democracy and constitutionalism. Such an alternative approach is consequential for Walker’s argument in two respects. In terms of the general analysis of the relationship between democracy and constitutionalism, my adjusted approach leads to a defence of the Habermasian thesis of the co-originality of constitutionalism and democracy which is too quickly dismissed by Walker himself. A fuller appreciation of this co-originality suggests that the relationship between constitutionalism and democracy is perhaps, after all, more singularly complementary (as opposed to being both complementary and oppositional) than Walker recognizes. In terms of the more specific analysis of the impact of globalization, this adjusted approach tilts the argument in favour of the critics of current practices of postnational constitutionalism. Without complementary postnational democratic structures, this constitutionalism remains problematic and potentially oppressive.

This paper agrees with Walker on the existence of a tension between democracy and constitutionalism, but questions whether democracy and (international) constitutionalism necessarily depend on each other. While democracy needs constitutionalism on normative grounds, as an empirical matter it may also rest on alternative political structures. Moreover, it is questionable whether democracy is indeed the solution to the incompleteness of international constitutionalism. Traditional forms of democracy do not lend themselves well to transplantation to the international level and could even intensify some problems of international governance. Attempts to democratize international relations should be carried out prudentially, with due regard for possible counterproductive effects.

This reply to critics reinforces and further develops a number of conclusions of the original paper. First, it answers the charge that it is biased in its discussion of the relative standing of constitutionalism and democracy today, tending to take the authority of the former for granted and concentrating its critical attention unduly on the incompleteness of democracy, by arguing that contemporary constitutionalism is deeply dependent upon democracy. Secondly, it reiterates and extends the claim of the original paper that the idea and practice of democracy is unable to supply its own resources in the development of just forms of political organization. Thirdly, it defends its key understanding of the overall relationship between democracy and constitutionalism as a ‘double relationship’, involving both mutual support and mutual tension. A fourth and last point is concerned to demonstrate how the deeper philosophical concerns raised by the author about the shifting relationship between democracy and constitutionalism and the conceptual reframing they prompt are important not just as an explanatory and evaluative window on an evolving configuration of political relations but also as an expression of that evolution, and to indicate how this new conceptual frame might condition how we approach the question of a democracy-sensitive institutional architecture for the global age.