The article explores the formation of the concepts of dialogue and pluralism as they relate to the spiritual heritage of Popes John XXIII and Paul VI. The Second Vatican Council (1962–1965) initiated the process of the so-called aggiornamento, i.e. the renewal of various aspects of Catholic teaching, and raised the question of revising the principles of relations between the Roman Catholic Church and modern society. Achieving the objectives of the Council necessitated a shift in the approach and tactics employed in communication, a transformation that could not be realized without acknowledging the indispensability of modern concepts such as pluralism and dialogue. These terms feature prominently in the vocabularies of Popes John XXIII and Paul VI, who, through their encyclicals and messages, have constructed a distinctive semantic framework around these concepts. The Catholic conception of pluralism does not imply plurality and equali ty of the components that make up society, but is divided into legitimate and illegitimate, with the criterion of legitimacy being defi ned by the unquestionable authority of the Holy See. The dialogue, which is predicated on the equality of the parties involved, is, in papal documents, reduced to a refined rhetorical and tactical device to achieve the unchanging goal of restoring the unity of the Christian world under the pope’s authority. This represents a shift in the Roman Catholic Church towards a form of realpolitik in its global relations, while maintaining its missionary objectives. However, this pragmatic approach is also characterized by a certain degree of ambivalence, as it grants the pontiff greater discretion in determining the limits of what is permissible, both in establishing the legitimacy of pluralism and in expanding or narrowing the targets, forms and methods of dialogue. This ambivalence was particularly evident during Pope Francis’s papacy, as evidenced by his openness to non-Christian spiritualities and alternative models of social organization, which elicited a range of reactions from both the general public and the Catholic clergy.