Ut Unum Sint

Background and Occasion

Thirty years after Vatican II’s Unitatis Redintegratio, John Paul II wrote the first encyclical devoted entirely to ecumenism. It was issued on the solemnity of the Ascension 1995, with the Jubilee of 2000 in view. The Pope had already made ecumenism a mark of his pontificate: he had prayed with the Archbishop of Canterbury in Canterbury Cathedral (1982), signed common declarations with Orthodox and Oriental Orthodox patriarchs, and convened the day of prayer for peace at Assisi (1986). The title comes from Christ’s prayer at the Last Supper (John 17:21).

Structure

After an introduction, the encyclical has three chapters: The Catholic Church’s commitment to ecumenism; The fruits of dialogue; and Quanta est nobis via? (How long is the road ahead of us?). An exhortation concludes it.

Central Teaching

An irrevocable commitment

The Pope begins by stating that, at Vatican II, the Catholic Church committed herself irrevocably to following the path of ecumenism. Unity is not an optional addition to the Church’s work; it belongs to her very being, because Christ willed one Church, and division openly contradicts his will and scandalises the world.

The first chapter recalls the Council’s teaching: the one Church of Christ subsists in the Catholic Church, and many elements of sanctification and truth exist outside her visible structure, so that other Christians are in real though imperfect communion with her. Ecumenism requires conversion of heart and prayer, which the Council called spiritual ecumenism and which the Pope calls its soul. Dialogue is not only an exchange of ideas but an exchange of gifts, and it is also an examination of conscience, in which each side recognises its own faults.

The Pope stresses that ecumenism does not mean compromising doctrine. Unity willed by God can be attained only through the common adherence to the integral content of revealed faith. But the expression of truth can take different forms, and the hierarchy of truths (Unitatis Redintegratio 11) helps dialogue to concentrate on what is central.

The fruits of dialogue

The second chapter surveys what had been achieved: a rediscovered brotherhood among Christians; common prayer; the mutual lifting of the excommunications of 1054 by Paul VI and Patriarch Athenagoras (1965); Christological agreements with the Oriental Orthodox Churches; and theological dialogues with the Anglican Communion, the Lutheran World Federation and other communities. The Pope speaks movingly of the ecumenism of the martyrs: Christians of different confessions who have given their lives for Christ are already united in the communion of saints.

The road ahead

The third chapter names five areas that still require study before a true consensus of faith can be reached: the relationship between Scripture and Tradition; the Eucharist; ordination as a sacrament to the threefold ministry of bishop, priest and deacon; the Magisterium of the Church, entrusted to the Pope and the bishops in communion with him; and the Virgin Mary, Mother of God and icon of the Church.

The ministry of Peter

The best-known passage concerns the primacy. The Pope recognises that the ministry of the Bishop of Rome is a difficulty for most other Christians, whose memories are marked by painful recollections. He describes the primacy as a ministry of unity and of mercy, the servant of the servants of God. While insisting that what is essential to the mission of Peter cannot be renounced, he invites the leaders and theologians of other Churches to a patient and fraternal dialogue on how the primacy might be exercised in a way open to a new situation, so that it could be recognised by all.

Theological Significance

Ut Unum Sint applies the ecclesiology of Lumen Gentium and Unitatis Redintegratio to the concrete state of ecumenical relations. It unites two convictions that some regard as in tension: that the Catholic Church possesses the fullness of the means of salvation, and that she must seek unity with humility, conversion and openness to the gifts of others.

Its invitation on the primacy led to a substantial body of responses from other Churches and to further study, including the Catholic–Orthodox Ravenna document (2007) and the Dicastery for Promoting Christian Unity’s study The Bishop of Rome (2024). Its distinction between the substance of the Petrine ministry, defined at Vatican I, and the forms of its exercise, which may vary, is now a fixed point of Catholic ecumenical theology.

For readers of this site, the encyclical is a companion to the ecclesiology tract’s treatment of the primacy and of membership in the Church, and to Satis Cognitum, whose doctrine on unity it presupposes while adopting a markedly different tone.