Where Does Public Reason Reside? The Justificatory Task in Constitutional Democracy

Public reason (PR) or public justification (PJ) theorising is now a well-established approach to the problem of legitimacy of political rule, including the legitimacy of law. One recurring issue concerns the locus of PR in a constitutional democracy. Which part of the political system is to be expected – required – to exemplify the imperatives of public reason? The common answers in political and constitutional theory have been (1) constitutional courts and (2) parliaments (I leave aside “deliberative civil society” here as it does not constitute an official state institution). My aim in this paper is twofold: I will first show that answers to this question depend on fairly specific answers to a logically prior one, namely what kind of PJ one expects a constitutional democracy to produce or exhibit. Second, I want to argue that insofar as the subject matter is constitutional democracy, there are good reasons to consider the legislative bodies, rather than highest judicial institutions, as primary repositories of justificatory capacity. These reasons have to do, among other things, with a more inclusive menu of justificatory methods parliaments can employ (which is why I prefer the term public justification to public reason); their relation of political representation to the citizens; or the relative cognitive homogeneity of constitutional courts (which is, arguably, epistemically disadvantageous, given the justificatory task). In defending the worth of parliaments, the paper also links PJ theorising to recent contributions highlighting the systemic role of political parties in a constitutional democracy.