"Public rationality" of J. Habermas in the context of the idea of value pluralism

The article focuses on the attempt of Jurgen Habermas to solve the so-called «dilemma of I. Berlin» (of pluralism and justification of norms and principles): how can one rationally prove his devotion to certain position and at the same time has pluralistic beliefs? The authors analyze the argumentation of Habermas in the context of modern problems of philosophy of science (especially, methodology of conventionalism), trying to show the narrowness of his concept of public rationality.