  Habermas's two enduring interests in political theory and rationality come together in his discourse theory of deliberative democracy. There we see him struggling to show how his highly idealized, multi-dimensional discourse theory has real institutional purchase in complex, modern societies. In that context, argumentation appears in the form of public discussion and debate over practical questions that confront political bodies. The challenge, then, is to show how an idealized model of practical discourse connects with real institutional contexts of decision-making. 