According to the realist critique of political moralism, contemporary political theory has neglected the idea of the state, and the coercive power of the state exercised through positive law, in favour of ideal theories of justice and democracy developed independently of political practice. The work of John Rawls and Jürgen Habermas is often seen as paradigmatic of such political moralism. In this paper I take the realist critiques of Raymond Geuss and Bernard Williams as an opportunity for reassessing the methodological approaches of Rawls and Habermas. I begin by distinguishing William’s idea of vindicatory genealogy from Geuss’s, I argue untenable, attempt to separate the method of genealogy as critique from the project of normative justification and I claim that Rawls and Habermas can be seen as employing the methods of reflective equilibrium and rational reconstruction for just such vindicatory purposes. I proceed to offer a genealogy of the idea of the democratic Rechtstaat, to situate Rawls and Habermas within this tradition and to argue that this tradition overcomes the unsatisfactory methodological dualism of realism versus moralism. The problem of offering a self-grounding justification of the modern democratic Rechtsstaat reflects the fundamental problem for philosophy in modernity of creating its normativity out of itself, of finding immanent normative foundations within existing social practices rather than appealing to transcendent ideal principles. I conclude that Rawls fails ultimately to meet this challenge but that Habermas’s project shows how a project of normative philosophical justification can be maintained that is consistent with realist strictures.
