This article aims to analyze the constitutional affirmation of cooperative federalism as an organizational model of the Brazilian state and the difficulties of its implementation. To do so, were used the post- positivist theories, that defend the indispensability of moral values for the legitimation of institutional practices, and some sociological theories that, analyzing the consolidation of the nation-state as the archetype of social organization of modernity, were able to distinguish the categories "state" and "nation" as not necessarily complementary elements. Through this distinction, the article tried to discuss the relationship among these categories in the construction of Brazil's social fabric.