History of Catholic Ecumenism
from Pope Leo XIII to Pope John XXIII
The Church of God, by a wondrous act of Divine Providence, was so fashioned as
to become in the fulness of time an immense family which embraces all men. - Pope Pius XI, Ecclesiam Dei, Art. 1.
The "ecumenical movement" would not have to exist if all things were in
accordance with Gods Will; if not for the human sins on all sides that caused
division, reunion attempts would not be necessary. But these divisions do exist, and to
fulfill the prayer of Jesus to his Father, men and women have striven to reunite the
separated Body of Christ. Included in those who have sought reunion is the Catholic Church
and her popes, especially in the century leading to Vatican II. Recognizing the great
number of difficulties that exist between believers, the Church attempted a prudent path
that at times was cautious and even suspicious, but always with an eye toward a return to
one fold under Christ. Also, since the divisions occurred for different reasons, popes
reacted accordingly. Knowing that the non-Catholic Eastern churches are indeed very close
to the bosom of the Catholic Church, Rome was quick to praise them and extend a hand of
reconciliation toward them. A great love for the Eastern churches is evident in the
writings of many popes this century, especially Leo XIII, Pius XI, and John XXIII, and
this love translated into many attempts to lessen the distance that separates East and
A greater distance, however, exists between Catholics and Protestants. This obvious
fact was clearly stated in many ways by Rome during the first half of this century. Though
still admitting of these differences, the Church in the immediate years preceding Vatican
II more deeply realized the need to strive earnestly for reunion, and thus began to
acknowledge the many true beliefs and virtues that Protestants possess.
Two popes especially distinguished themselves for their willingness to initiate
ecumenism. Leo XIII, in regards to the East, and John XXIII, in reference to Protestants,
were pioneers in encouraging official Catholic involvement with non-Catholic Christians.
The culmination of these efforts was realized in Unitatis Redintegratio. This
historic document of the Church introduced a new era of ecumenism within Christianity.
Much of the distrust which had existed was removed by its openness toward the separated
brethren. Although many commentators believe this was the first ecumenical action of the
Catholic Church, a closer look reveals that the Church, including many popes, took a keen
interest in ecumenical affairs even before Vatican II. The result is that this century saw
popes and the entire Catholic Church attempt to follow the prayer of Jesus that "they
may all be one".