Unitatis Redintegratio

Background and Occasion

John XXIII named the restoration of Christian unity as one of the chief aims of the Council, and in 1960 he created the Secretariat for Promoting Christian Unity under Cardinal Augustin Bea. Observers from the Orthodox Churches and the Protestant communities attended the Council’s sessions, a striking change from the absence of any such presence at Trent or Vatican I. The modern ecumenical movement had grown up largely outside the Catholic Church, through the World Council of Churches founded in 1948, and Pius XI’s Mortalium Animos (1928) had kept Catholics at a distance from it.

Unitatis Redintegratio was promulgated on 21 November 1964, the same day as Lumen Gentium and the decree on the Eastern Catholic Churches, after a vote of 2,137 to 11. It is meant to be read with Lumen Gentium, whose teaching on the Church it applies.

Structure

After an introduction, the decree has three chapters: Catholic principles of ecumenism; the practice of ecumenism; and the Churches and ecclesial communities separated from the Roman Apostolic See, divided into the Eastern Churches and the separated Churches and ecclesial communities of the West.

Central Teaching

Catholic principles

The decree begins from Christ’s will that his Church be one, and from the Church’s unity in faith, sacraments and the government of the successors of the apostles under Peter (UR 2). It then describes the situation of divided Christians. Those who are now born into separated communities and are brought up in the faith of Christ cannot be charged with the sin of separation, and the Catholic Church accepts them with respect and love as brothers. Justified by faith in Baptism, they are incorporated into Christ and rightly called Christians (UR 3).

Many elements of sanctification and truth exist outside the visible boundaries of the Catholic Church: the written Word of God, the life of grace, faith, hope and charity, other gifts of the Spirit and visible elements. These belong by right to the one Church of Christ, and the Spirit uses the separated Churches and communities as means of salvation, whose power derives from the fullness of grace and truth entrusted to the Catholic Church (UR 3). Yet the fullness of the means of salvation is found only in the Catholic Church.

The practice of ecumenism

The second chapter treats renewal of the Church as the basis of ecumenism (UR 6) and calls for interior conversion, since there can be no genuine ecumenism without a change of heart (UR 7). It names spiritual ecumenism, prayer for unity together with conversion and holiness of life, as the soul of the whole movement (UR 8).

It also introduces the principle of the hierarchy of truths: in comparing doctrines, Catholics should remember that truths vary in their relation to the foundation of the Christian faith (UR 11). This does not mean some revealed truths may be denied; all are held with the same divine faith. It means that some truths are more central, and that others are understood in relation to them. The same article insists that doctrine must be presented clearly and in its entirety, since a false irenicism harms the purity of Catholic teaching.

The Eastern Churches

The decree speaks with special warmth of the Eastern Churches. They possess true sacraments, above all, by apostolic succession, the priesthood and the Eucharist, by which they remain joined to the Catholic Church in a very close relationship (UR 15). The Council recognises the legitimacy of their own disciplines and theological traditions and recalls that a diversity of customs is no obstacle to unity (UR 16–17).

The Western communities

Of the communities that arose from the Reformation, the decree singles out the Anglican Communion as holding a special place, because it preserves Catholic traditions and institutions in part (UR 13). It honours their love for Scripture and their baptismal life, but notes that, because of the lack of the sacrament of orders, they have not preserved the proper reality of the Eucharistic mystery in its fullness (UR 22). It calls for dialogue on the Church, the sacraments and the moral life.

Theological Significance

Unitatis Redintegratio committed the Catholic Church irrevocably to the ecumenical movement, as John Paul II later said in Ut Unum Sint (1995). Its distinctive contribution was to describe divided Christians not as simply outside the Church but as in real, though imperfect, communion with her. This rests on Lumen Gentium 8, where the Church of Christ is said to subsist in the Catholic Church, with many elements of sanctification found outside her structure.

The decree also produced a body of later clarification. The Directory for the Application of Principles and Norms on Ecumenism (1993) governs practice, and the Congregation for the Doctrine of the Faith’s Dominus Iesus (2000) and Responses to Some Questions (2007) explain the distinction between Churches with valid sacraments and apostolic succession and ecclesial communities without them.

For readers of the ecclesiology tract on this site, the decree is the modern complement to the classical treatment of the marks of the Church and of membership in the Church in Pohle and the manuals. The manuals’ distinction between belonging to the Church in reality and in desire is developed here into a theology of degrees of communion.