The years from 1919 to 1959 saw the publication of five “Mission Encyclicals”
published by Popes Benedict XV, Pius XI, Pius XII, and John XXIII.5 These are important
documents for understanding the development of missionary thinking in the Catholic
Church, particularly in terms of appreciating the values of local cultures and the call for
the establishment of an indigenous clergy. One might make the argument that these
encyclicals presaged the Council’s statement that the “church is missionary by its very
nature.”
6 However, it might be more exact to conclude that although mission was of
supreme importance in the church, for its task was to establish or “plant” the visible
church with its hierarchy in all parts of the world, it was not yet seen as constitutive of the
church itself.7 Such a perspective would depend on the Council’s more biblical, patristic,
and Trinitarian perspective of ecclesiology, developed, in part, at least, as a result of the
church’s growing ecumenical openness throughout the first half of the twentieth century.
Yves Congar intimates, for example, that the pivotal statement on the church’s missionary
nature quoted above— that “the pilgrim church is missionary by its very nature, since it is
from the mission of the Son and the Holy Spirit that it draws its origin, in accordance with
the decree of God the Father” (AG n.2)—is influenced as much by the Missio Dei theology
of Willingen as it is by more traditional Catholic theology.8
This powerful statement of the church’s missionary nature as rooted