28. If prayer is the "soul" of ecumenical renewal and of the yearning for unity, it is the basis and support for everything the Council defines as "dialogue". This definition is certainly not unrelated to today's personalist way of thinking. The capacity for "dialogue" is rooted in the nature of the person and his dignity. As seen by philosophy, this approach is linked to the Christian truth concerning man as expressed by the Council: man is in fact "the only creature on earth which God willed for itself"; thus he cannot "fully find himself except through a sincere gift of himself".51 Dialogue is an indispensable step along the path towards human self-realization, the self-realization both of each individual and of every human community. Although the concept of "dialogue" might appear to give priority to the cognitive dimension (dia-logos), all dialogue implies a global, existential dimension. It involves the human subject in his or her entirety; dialogue between communities involves in a particular way the subjectivity of each.

This truth about dialogue, so profoundly expressed by Pope Paul VI in his Encyclical Ecclesiam Suam,⁵² was also taken up by the Council in its teaching and ecumenical activity. Dialogue is not simply an exchange of ideas. In some way it is always an "exchange of gifts".⁵³

29. For this reason, the Council's Decree on Ecumenism also emphasizes the importance of "every effort to eliminate words, judgments, and actions which do not respond to the condition of separated brethren with truth and fairness and so make mutual relations between them more difficult".54 The Decree approaches the question from the standpoint of the Catholic Church and refers to the criteria which she must apply in relation to other Christians. In all this, however, reciprocity is required. To follow these criteria is a commitment of each of the parties which desire to enter into dialogue and it is a precondition for starting such dialogue. It is necessary to pass from antagonism and conflict to a situation where each party recognizes the other as a partner. When undertaking dialogue, each side must presuppose in the other a desire for reconciliation, for unity in truth. For this to happen, any display of mutual opposition must disappear. Only thus will dialogue help to overcome division and lead us closer to unity.

30. It can be said, with a sense of lively gratitude to the Spirit of Truth, that the Second Vatican Council was a blessed time, during which the bases for the Catholic Church's participation in ecumenical dialogue were laid. At the same time, the presence of many observers from various Churches and Ecclesial Communities, their deep involvement in the events of the Council, the many meetings and the common prayer which the Council made possible, also helped bring about the conditions for dialogue with one another. During the Council, the representatives of other Churches and Ecclesial Communities experienced the readiness of the worldwide Catholic Episcopate, and in particular of the Apostolic See, to engage in dialogue.