The article discusses the stages of reception by Catholic theology of the concept of “sobornost”, which was included in the Dogmatic Constitution on the Church “Lumen Gentium” (“Light to the Peoples”). The author briefly describes the history of the emergence of this term in the writings by A. S. Khomyakov and analyzes the works by Cardinal Yves Congard, Fr. Bernhard Schultze, Abbot Albert Gratieux, Fr. Paul Patrick O’Leary, Fr. Hyacinthe Destivelle, in which this concept was critically comprehended, and thanks to which it was assimilated by the Roman Catholic Church in an updated format. The article analyses the relationship between the concepts of sobornost, catholicity, synodality, conciliarity and collegiality, which are closely connected in contemporary Catholic ecclesiology. These categories are compared with the principle of primacy and the ecclesiastical authority of teaching. The author notes the insufficiency of sobornost without the reality of the sacrifice on the cross, so it must take into account aspects of the relationship between love and the law. The path taken by the concept of “sobornost” from the desk of A. S. Khomyakov to the documents of Vatican II can be viewed as a miracle and an opportunity for dialogue between East and West. The comprehension of Khomyakov’s works by leading Catholic theologians certainly contributes to a deeper analysis of his legacy in Orthodox theology.