The impulses of Pope Francis concerning the unity of Christians are based on his way of thinking, which is shaped by spiritual depth, theological study and life experience. The text examines the sources of Bergoglio’s forma mentis in Jesuit spirituality, in the philo- sophy of Romano Guardini, and in the historical context of Latin America in the second half of the twentieth century. The focus here is on the antinomic understanding of reali- ty as the core of Bergoglio’s intellectual world, which allows him to formulate a pastoral programme of “culture of encounter” that becomes a means of reconciliation in society, in the Church, but also among Christians. Subsequently, the key features of Francis’ understanding of ecumenism are presented on the background of these realities. Continuity with the previous Magisterium teachings as well as new impulses of the contemporary Roman Pontiff are illustrated with the example of the antinomic perception of unity as a manifestation of Catholic universality, on the role of the Holy Spirit in the ecumenical process and on the conversion of the heart, which constitutes the spiritual precondition of any attempt at unity.