The article intends to analyse the problem of the coexistence of opposite and alternative “comprehensive doc- trines” in today's Western society, on the basis of a comparison between the thought of Schmitt, Böckenförde, Habermas, Rawls and Charles Taylor. In this regard the article proposes a possible solution to avoid, on the one hand, the intolerant goal of a total homogeneity, and on the other a naive and aproblematic acceptance of a relativistic multiculturalism.