In late June 1943, in the teeth of the Second World War, Pope Pius XII issued the most important 20th-century document on the Church prior to the Second Vatican Council (1962-65), namely his encyclical letter on the “Mystical Body of Christ” (Mystici Corporis Christi). We observed its 65th anniversary less than two weeks ago.
Although Pius XII became an especially controversial figure after his death in 1958 because of his allegedly passive role during the Holocaust, he did open Catholic theology to the fruits of modern biblical scholarship with another encyclical published later the same year, Divino afflante Spirit (“Inspired by the Holy Spirit”), which Catholic biblical scholars embraced with enthusiasm. And in 1947 his encyclical Mediator Dei (“Mediator of God”) prepared the way for the liturgical renewal and reforms promoted by Vatican II.
Mystici Corporis, however, represented the most significant shift in ecclesiology (the theological understanding of the nature and mission of the church) since the Counter-Reformation of the late 16th and early 17th centuries.
For perhaps the first time in modern church history, a pope rooted his teaching on the church in Scripture, especially the writings of St. Paul on the church as the Body of Christ. The encyclical did qualify the expression with the non-Pauline adjective “mystical,” but only to distinguish the ecclesial Body of Christ from the Eucharist and from his earthly, risen and glorified bodies.
Although a residue of juridical and legalistic thinking still permeated the encyclical, it nonetheless marked a point of transition in 20th-century Catholic doctrine and theology, and prepared the way, at least to some extent, for Vatican II.
To be sure, a revival of the theology of the church as the mystical body of Christ had begun already in the 1930s in the writings of the Belgian theologian Émile Mersch, who retrieved the thought of the Eastern Fathers. Cyril of Alexandria, for example, had stressed the physical and organic union between Christ, the head of the church, and every member of the church.
The encyclical Mystici Corporis rejected two extreme ways of viewing the church. The one saw it as an exclusively hierarchical reality; the other as a purely charismatic entity.
There can be no real opposition or conflict, Pius XII insisted, between the invisible mission of the Holy Spirit and the juridical commission to teach and govern received from Christ. On the contrary, they mutually complement and perfect each other, as do the body and the soul in every person.
The church, the encyclical continued, does not consist of the hierarchy alone but of all the baptized, laity as well as clergy and religious. And all of them are called to holiness.
The source of this holiness is the Holy Spirit, who is the very heart and soul of the church. It is the Holy Spirit who creates and sustains its unity.
Indeed, the Holy Spirit is available to, and guides, every baptized member of the church, not just the hierarchy or the clergy and religious.
The encyclical also made the important point that, while Peter and his successors in the primacy are vicars of Christ, the church has only one head, namely Jesus Christ. Bishops, however, are “subordinate to the lawful authority of the Roman Pontiff, although enjoying the ordinary power of jurisdiction which they receive directly from the same Roman Pontiff” (n. 42).
To be sure, these words were written some two decades before Vatican II’s Dogmatic Constitution on the Church and its teaching on episcopal collegiality. Another residue of Counter-Reformation ecclesiology was the encyclical’s insistence that only Catholics are true members of the church (n. 22).
This teaching was taken to its logical extreme a few years later by Father Leonard Feeney, SJ, who interpreted the medieval axiom literally: “Outside the church, no salvation.” The Vatican was compelled to distance itself from Father Feeney’s interpretation, insisting that there are various ways of being in a saving relationship with the church, including, in Pius XII’s words, “an unconscious desire and longing” (n. 103).
The encyclical also anticipated the council’s Declaration on Religious Freedom by condemning the use of compulsion to bring people to embrace the Catholic faith against their will (n. 104).
Vatican II would later set aside the category of membership (one is either in or out of the church) entirely in favor of “degrees of communion,” as exist, for example, in an extended family.
Whatever the encyclical’s strengths and weaknesses, Mystici Corporis did signify an important transition from the prevailing ecclesiology of the Counter-Reformation to one more biblically based and open to the role of the Holy Spirit in the church’s life and mission.
Father McBrien is a professor of theology at the University of Notre Dame.
