In Pope Francis’ opening address to the Synod on synodality, he referred, in passing, to the book of the French Catholic ecclesiologist and ecumenist, Yves Congar, OP (1904-1995), True and False Reform in the Church . Without explanation, Francis gives an abridged quote from Congar, “’There is no need to create another Church, but to create a different Church.’ That is the challenge.” What is the difference between “another church” and a “different church?” I presume Francis is emphasizing ecclesial sameness, such that the Church remains the same even through authentic reform. Still, unlike Congar, Francis makes no reference to the conditions for authentic reform, without schism.
Francis is somewhat sensitive to the criticism that synodality runs the risk of treating a listening and dialogical Church as an end in itself – an open-ended series of discussions about the normative content of Christianity – rather than as an instrument in the service of the teaching Church, deepening our understanding of the Church’s normative faith.
Turning to Congar, then, how does the great Dominican distinguish between true and false reform in the Church, while making clear the conditions for authentic reform without schism? There are four such conditions.
1) What does Congar mean by claiming that the challenge throughout his entire book “is not to change the church but rather [to change] something within it.” He explains, “We don’t need to create another Church; what we need to some degree is a church that is other.” In short, it is not the Church as such that is called into question. It is the Church as an existing reality that is renewed. “The Church preexists the reform effort and therefore it is not the object of discovery, retrieval, or creation.” The Church as such possesses “immutable elements divinely instituted, and [also] elements subject to change” (Sacrosanctum Concilium, no. 21).
Congar makes reference in this context to the notion of “double fidelity”:
One kind of fidelity exists only at the level of articulated forms and formulas [of the Church’s dogmatic teaching]. But there is also a fidelity that includes the possibility of surpassing these forms. . .through a deeper penetration into the [dogmatic] principle or through a more intense movement toward fulfillment.
This double fidelity alludes to the distinction between propositional truths of faith and their reformulations. Indeed, the formulations may change but not the fundamental content of the faith, because the meaning and truth of the latter remains always the same. Authentic reform excludes doctrinal relativism.
Similarly, on Catholic ecumenism, particularly on the question of ecclesial unity and diversity, Congar insists that that unity is a given, a gift, existing already in the Catholic Church, rather than something we strive after from the starting point of non-Catholic diversity of Christian confessions. Congar rightly insists, “For its part, a Catholic ecumenism cannot forget that the church of Christ and the apostles exists. Therefore, the point of departure for Catholic ecumenism is this existing church, and its goal is to strengthen within the church the sources of catholicity that it seeks to integrate and to respect all their legitimate differences.”
In short, ecumenical development “would be that of the Catholic Church – and in this sense it would not be another church, that is, an ecclesial body other than the Catholic Church, the Church of Christ and of the apostles.” Authentic reform regarding Catholic ecumenism excludes ecclesial relativism in which the Catholic Church is one among many churches.
2) Congar stipulates that in order to avoid sliding into schism, the call for authentic reform requires remaining in “Communion with the Whole Church.” He explains that the condition for knowing but also deepening our understanding of the truth:
Only through communion with the whole body, which itself is subject to the guidance of the magisterium [see Lumen Gentium, no. 12], can someone grasp a truth in its totality [emphasis added]. It is clearly impossible that individual persons might know and profess the whole truth by themselves. . . .When we are in communion with the whole body, [with the one, holy, catholic, and apostolic church] we have the benefit of corrections, clarifications, and the fullness [of truth] that the whole body offers us.
This conclusion brings us back to Congar’s first point that the Catholic Church as an already existing reality is a starting point of authentic reform.
3) History and truth: There is a historical dimension to the clarification of unchangeable doctrinal truth. According to Congar, history shows continuity, indeed, identity persisting from the apostolic deposit, which is a determinate revealed datum, to the developed assertions of Church dogma. Although the truths of the faith may be expressed differently, they must be kept within determinate bounds. That is, we must always determine whether those re-formulations preserve the same meaning and mediate the same judgment of truth. Authentic dogmatic development must preserve the material continuity, identity, and universality of those truths, unfolding and hence enriching our understanding of the truth. Significantly, Congar concludes, “It should be clear that what is true remains true, despite the flow of time.”
4) Ressourcement: “Genuine Renewal through a Return to the Principle of Tradition (Not through the Forced Introduction of Some ‘Novelty’).” Congar calls the Church to return to the authoritative sources of the faith – Scripture and tradition – for the sake of revitalizing the present, that is biblical interpretation, theology, in sum, the church today – “all under the guidance of the magisterium.” “In welcoming it [the return to the “sources” in ressourcement], the authorities test it, direct it, keep it within limits, and correct it. For a movement, especially a reform movement, to become truly an ecclesial movement, a reform of the church, and not deviant or schismatic, it has to be inserted within the established lines of the church’s structure.”
These are the necessary conditions for realizing reform inside the church. Without attending to them we’ll have schism or disruption of the church. The Synod on synodality would do well to attend very carefully to these conditions.
You may also enjoy:
Robert Royal’s Seriously, Synodal? 
Stephen P. White’s A Long View of Vatican II