Karl Rahner and the Elusive Search for Christian Unity

Despite his prominence within the landscape of theology, Karl Rahner is largely absent in ecumenical discourse. This is surprising considering the concern he shows for both the church’s unity and ecumenism throughout his writings. Rahner’s understanding of unity and diversity and their relationship to one another has the potential to provide important resources for the contemporary ecumenical movement and the goal of visible unity. This article examines Karl Rahner’s theological understanding of ecumenism and the relationship of ecumenism to the realities of unity and diversity. This article explicates Rahner’s theologies of symbol and unity as prerequisites for understanding and developing the relationship between unity and diversity. The unity of the Church is fundamentally a symbolic reality in the process of “becoming”.


Introduction
Unity, from the earliest writings of Paul up through the contemporary ecumenical movement, is a reality that Christians have struggled to establish, maintain, develop, and achieve.As David Chapman observes in his article Ecumenism and the Visible Unity of the Church, "[f]rom the time of the apostles, Christian history has been marked by the tension between confessing the essential unity of the Church and the historical reality of disunity among Christians."(Chapman 2015, p. 352).While experienced with varying intensity, divisions are not unique to any one particular period of Christian history.On the one hand, Christians throughout history affirm that the fullness of the church's unity will be realized as an eschatological goal.On the other hand, most Christians affirm that unity exits, albeit imperfectly, through common baptism.The criteria for what exactly constitutes the essential visible unity of the Church and what kinds of diversity warrant disunity vary throughout history and between particular churches.Despite the opaque nature of a precise articulation of what entails visible unity and possible disunity, it is clear that the unity of the Church involves the realities of unity and diversity and their relationship to one another.John Zizioulas writes: The most important condition attached to diversity is that it should not destroy unity.The local church must be structured in such a way that unity does not destroy diversity and diversity does not destroy unity.This appears at first sight to be a totally unrealistic principle.And yet, the carful balance between the "one" and the "many" in the structure of the community is to be discovered behind all canonical provisions in the early church.(Zizioulas 2010, p. Kindle Location 1457-60) The relationship between unity and diversity is one that is both fraught with tension and requires careful discernment as to what constitutes "legitimate unity" and "acceptable diversity".In a particularly poignant way, questions of legitimate unity and acceptable diversity and their relationship to one another lie at the heart of the contemporary ecumenical movement's work.
The following looks to the writings of Karl Rahner as a resource for the contemporary ecumenical movement's work in discerning the relationship between unity and diversity and their relationship to one another.In particular, the following takes up Rahner's theology of unity and symbol as potential sources for discerning the ecumenism's goal of "visible unity in one faith and one eucharistic fellowship, expressed in worship and in common life in Christ."(World Council of Churches 2018)

Karl Rahner: Unity and Symbol
As is typical of Rahner's theology in general, the nature of his writings on Ecumenism are tentative insofar as they address particular questions that arise at a particular time.When viewed together, Rahner's works demonstrate an ever-increasing concern for ecumenism and its necessity for the church of the future.His writings on ecumenism, like much of Rahner's work, develop and mature over the course of his life and career.His first writings on the topic of ecumenism appear as lectures given in the late 1940s and began as isolated investigations into questions surrounding conversion.However, the topic of ecumenism continued to appear with ever greater frequency and depth throughout the course of Rahner's life and work, culminating with his final work The Unity of the Churches: An Actual Possibility.While never developing a complete theology of ecumenism, a considerable amount of Rahner's work directly or indirectly responds to concerns vis-à-vis ecumenism.Notwithstanding the complexities and developments in Rahner's theological investigations on the topic of ecumenism, a common thread that runs throughout his work on the topic are the concepts of symbol and unity.This section provides a brief analysis of the interrelated concepts of symbol and unity as a preliminary discussion to articulating the contours of Rahner's ecumenical thought.

Theology of Symbol: Church, Word, and Sacrament
The reality of being, according to Rahner, is not a static principle or substance.Instead, being obtains through a complex plurality of origin and expression.Unity-in-difference characterizes existence for Rahner through a process of emanation and return where being moves towards expression to be realized and known both for itself and for the other.Firstly, Rahner holds that "all beings are by their nature symbolic, because they necessarily 'express' themselves in order to attain their own nature."(Rahner 1966a, pp. 221-52) Hence, being is fundamentally self -expressive insofar as there is an ontological affinity between being and its expression.The notion that being is self-expressive challenges traditional Western metaphysical convictions that explicitly or implicitly suggest that plurality and difference somehow threaten unity.In place of an interpretation that accords the primacy of the one over that of the many, the original unity of the symbol provides for the possibility of difference and difference provides for the possibility of original unity's expression.As such, difference owes itself to unity and the expression of unity owes itself to difference.Secondly, Rahner contends that being's expressive movement into its own other is completed by its return to itself and that it is through the return to self that being realizes itself.Accordingly, "[t]he symbol strictly speaking is the self-realization of a being in the other, which is constitutive of its essence."(Rahner 1966a) Succinctly put, "a symbol is effective because it brings a being to reality" both for itself and for others.(Vorgrimler 1992).In sum, beings consist of three aspects: an original unity, an "other", and a perfected unity.
Rahner begins his analysis on the symbolic and sacramental nature of the Church by asserting that, "[t]he Church is not merely a religious institution . . .But neither was it simply founded from above by Christ as a spiritual welfare establishment."(Rahner 1964, p. 193).If the salvific presence of God's grace is to be really present in the world through the human being, it must arise in the world in what is other than God.In short, it must come to the human being in a manner that is in accord with the experience of the human person.The Church brings itself to expression and realizes itself fully in both word and sacrament.In his essay, Word and Eucharist, Rahner demonstrates the hermeneutical significance of a theology of symbol in relationship to the fundamental activities of the Church.Here, he develops six guiding theses.
(1) "[t]he word of God is uttered by the Church, where it is preserved inviolate in its entirety, and necessarily so, in its character as the word of God." (Rahner 1966b, p. 257).The Church and the word, while distinct, are united with one another in such a way that wherever the word is preached the Church is present and wherever the Church is the word is present.The Church cannot exist without the word of God and the word of God is a reality insofar as the Church preaches it.( 2) "[t]his word of God in the Church is an inner moment of God's salvific action on man." (Rahner 1966b, p. 257).There is an intrinsic relationship between the inner word of God's grace and the event of God's word spoken externally to the human being.The inner word is illuminated by the proclamation of God's word whereby, "[t]he proclamation of the word of God, that is, the word insofar as it is conveyed by the historical, external salvific act of God as an intrinsic moment of this act and by the community of believers, belongs necessarily to the inner moments of God's action on man." (Rahner 1966b, p. 259) (3) "As an inner moment in this salvific action of God, the word shares in the special character of the salvific action of God in Christ (and in the Church)."(Rahner 1966b, p. 259).Rahner affirms that the transcendental experience of the human being, as an inner moment of God's grace, must find expression in human terms.In other words, the gift of justifying grace that is extended to all of humanity and forms the supernatural existential of the human being, must have a categorical expression. 1 "Should this kind of expression be lacking salvation would be just some 'secret depth' within the soul."(Vass 2005, p. 17) (4) "[t]his word of God . . . is the salutary word which brings with it what it affirms."(Rahner 1966b, pp. 259-60).Here is where the full weight of Rahner's understanding of symbol is brought to bear on the discussion.The expression and what is expressed are united in their difference.The word of God really brings about the salvation that it proclaims.( 5) "This word . . .takes place in the Church in essentially varying degrees of concentration and intensity."(Rahner 1966b, p. 263).Here, Rahner makes an important observation that should not be overlooked nor minimized; he recognizes that not all symbols are equal.The efficacy of the symbol is in some sense determined both by its proclamation and by its reception.Rahner writes that word of God that is proclaimed by the Church "can realize its essence only in a historical process, it is not always and at every moment fully its whole self: it grows, it becomes what it is and must be, it can be deficient, provisional and preparatory phases and moments."(Rahner 1966b, p. 264) (6) "The supreme realization of the efficacious word of God, as the coming of the salvific action of God in the radical commitment of the Church . . . in the situations decisive for the individual's salvation, is the sacrament and only the sacrament."(Rahner 1966b, p. 265) Sacraments are most properly understood as symbols or events of God's self-communication in the world of which the Church is fundamentally related.Rahner writes: By such "natural symbols" or intrinsically real symbols, we mean for our purpose here, the spatio-temporal, historical phenomenon, the visible and tangible form in which something that appears, notifies its presence, and by so doing, makes itself present, bodying forth this manifestation really distinct from itself.With natural symbols, the sign or symbol as a phenomenon is intrinsically linked to what it is a phenomenon of, and which is present and operative, even though really distinct.In fact we must distinguish between two aspects: the dependence of the actual manifestation on what is manifesting itself, and the difference between the two.(Rahner 1964, pp. 219-20). 1 The supernatural existential is a term Rahner employs to explain the relationship between nature and grace.The term is used to navigate the extremes of extremism on the one hand and the gratuitous nature of grace on the other.See: (Duffy 2005).
Whenever and wherever the Church actualizes its essence, it does so as the real symbol of Christ's redemptive grace.

Theology of Unity
As is evidenced by his articulation of the symbolic nature of being, Rahner maintains that, "plurality as such is not a ground of unity" and with the scholastic tradition affirms that unity precedes plurality. 2(Rahner 1981, pp. 154-72).While maintaining that unity is logically prior to plurality and difference, unity does not strip plurality and difference of its importance and significance.Instead, as with symbol, Rahner advances unity as a reality that entails difference.He articulates three fundamental ways that unity obtains: (1) as existing, (2) as becoming, and (3) as unifying unity.
When Rahner speaks of unity as existing, he means that "[i]n the individual existent there is a unity already present which implies both the positivity of the sensible unitedness of the plural essential constitutive elements together with the unity of quiddity and actuality."(Rahner 1981, p. 155).Furthermore, the unity of oneself and the unity of oneself with another is "already" a reality, but "not yet" at its goal; it is already insofar as it exists and not yet insofar as it has a transcendental goal.The reality of unity, thus, entails a process of becoming.Rahner writes: If and in so far as each individual existent with its initial unity belongs to the world of becoming and unity is a transcendental determination of every existent as such . . .then to every existent there belongs also a unity imposed on it as a task, a unity still to be realized as telos (goal) of its becoming.(Rahner 1981, p. 154) Unity is not only given as existing; it is also to be acquired as a task.Unity is realized as a task through human freedom and in human history.As such, unity as a task is always provisional and tentative insofar as it is unity in the process of becoming and not unity at its transcendental goal.Unity develops, as a task, in relationship to the concrete decisions of human beings as free and responsible subjects.Thus, unity is expressed and unfolds within humanity's history while also being determined by history to some extent.Unity's concrete expression, as both free chosen and also contingent, can legitimately vary from one context to another.Rahner writes: There are processes within a historically existing reality which . . .can be recognized as legitimate by the nature of this existing reality even though they spring from a free decision and even though these processes and decisions cannot be proved to be the only possible ones . . .and hence cannot be proved to be the only obligatory means for the nature of the historically evolving reality.(Rahner 1966c, p. 228) Unity as a task, obtains through the concrete choices and activity of human beings.Hence, when unity obtains a concrete and visible expression, it does so in accord with its nature, but this need not imply that all expressions of unity are identical.In short, it is possible to manifest unity through a variety of expressions and choices that are all in accord with the nature of unity.Thus, it is possible for unity as a task to unfold and develop along a variety of paths with respect to different and legitimate processes and decisions.
Lastly, Rahner attends to what he terms "unifying unity."Both unity as task and unity as existing are sustained by God's unifying activity."[T]he already present unity of the individual existent and the unity to be acquired of the existent coming to be" writes Rahner, "presuppose an ultimate unifying unity."(Rahner 1981, p. 156).Hence, the "'superessential' unity which . . .becomes more interior to us than the unity of our being . . . is not our own . . .In this unity . . . the conflict which takes place within our 2 (Fletcher 2000).Rahner maintains the Thomistic claim of God's simplicity to ensure God's unity of Being, but this does not rule out the idea that from the human perspective this infinite simplicity contains all that we see as endless complexity.Read as the inexhaustible source of complexity, God's incomprehensibility encountered in transcendence opens one up to the unlimited expanse of all possible reality.own being between diffusion and compression, extroversion and introversion . . . is reconciled without thereby disappearing altogether."(Rahner 1977, p. 233) God as ground and telos is not a solution to the "problem" of unity.Instead, the Trinity is the source and the goal of all that exists as the mystery that unfolds in human history like the ever-receding horizon.To use a pithy expression, God's simplicity is not so simple for us.Rahner writes: The unity to be achieved of an increasing interiorization and the increasingly far-ranging quest to include a wider environment are correlative.But this implies that the increasingly close approach to the unity to be achieved carries with it a continual growth of internal and external elements of that unity.In this way unity as task remains within the world of becoming and of history as such always as a goal approached merely asymptotically, never finally attained, since advancing unity is always producing new material that has still to be integrated into unity.(Rahner 1981, p. 156) As the ground and transcendent goal of unity, God is never fully grasped, comprehended, or conceptualized, but the human being does really experience and encounter God even via unthematic involvement.
As the above demonstrates, Rahner's logic of symbol is closely linked to his theology of unity.Unity as existing is distinct from the unity in the process of becoming which is always realized in time and space as a task via the free activity of human beings aided by the unifying grace of God.The task, which visibly manifests the unity that already exists, really does effect what it signifies.Simply put, unity as a task is not identical to unity as existing or unifying unity, but unity as a task really brings about or affects the unity that it signifies; unity is realized or becomes a categorical and concrete reality as a task.However, the task and goal of unity is not the homogenization of diverse subjects, but instead the task and goal of unity is the reconciliation of "innumerable subjects, each different from others and simultaneously possessing the whole in each individual and each in a unique way." (Rahner 1981, p. 157).Unity is always a unity-in-difference not a unity-in-conformity.
Further, Rahner maintains that as free personal subjects, human beings only asymptotically realize unity in history by loving the other, where love is understood as "the consummation of unity in accepting the absolute otherness of everyone else (in accepting this other as one's very own) and thus the reconciliation between universal unity and enduring plurality, which itself is accepted as good, as its own, by the loving subject."(Rahner 1981, p. 157).Theologically speaking, one can achieve authentic unity by loving one's neighbor.Rahner argues that recognizing the unity between love of neighbor and love of God is essential for the mission of the church insofar as "[a]ll merely theoretical talk . . ., all worship even, everything explicitly religious would no longer appear credible to people today unless it were based on, comprised in and attested by genuine love, and that means love between human beings."(Rahner 1968, p. 105).The call to love one's neighbor, is rooted in the Christian conviction that God calls all of humanity along with its plurality and difference into existence (existing unity) and that God also calls all of humanity towards a common salvific destiny (unifying unity).However, in between origin and end, human beings realize in history God's loving self-communication whenever they in freedom and responsibility manifest God's command to love the other.

Rahner and the Nature of Ecumenism
As the above anticipates, Karl Rahner's understanding of the ecumenism is a logical outgrowth of his theological investigations on symbol and unity.Rahner's writings on the subject were deeply influenced by his observations on the changing context of the world and the effects of globalization."The emergence of the Church as a world-church" Rahner writes, "is in fact . . .brought about by a newly emerging unity of humankind and by the ensuing development of global social activity and planning for this unified humankind."(Rahner 1991a, p. 109).The emerging unity of humankind to which Rahner refers is a unity that he recognized both flourishes and is indebted to difference.Rahner's writings are often permeated by a hopefulness that the church is beginning to recognize that its unity is not achieved by conformity to identical expression; instead, the unity of the Church is better understood and explained as a unity-in-difference.In fact, Rahner acknowledges that the ecumenism emerges within the context of a globalized and pluralistic world, but rightfully maintains that the present state of things is not the raison d'être of ecumenism.Rahner explains: . . . it must be unreservedly conceded that for ecumenical dialogue and ecumenical theology in the form in which it appears today a liberal humanism, with its defense of freedom of opinion and faith within a pluralistic society, has been, and still is, the occasion and the context without which the pursuit of ecumenical theology as it de facto exists today is inconceivable . . .This liberalism, however, is hardly the true ground . . . of the ability which the separated parties have of conducting a dialogue today.So we must not confuse the essential basis for a given phenomenon with the historical situation in which such an essential basis becomes effective.(Rahner 1974, p. 33) While he admits that the present sociocultural and philosophical milieu provides the awareness and the resources for ecumenism to emerge, the source and foundation of ecumenism "is that unity, apprehended in hope, which consists in a belief in justifying grace, a belief which, even though in its theological formulation and its explication in creedal form it is still in process of being arrived at, is nevertheless already in existence as one and the same belief in both of the parties involved in ecumenical theology."(Rahner 1974, p. 33).By way of initial observation, four features can be identified as characteristic of Rahner's understanding of ecumenism.
(1) All churches are in the process of becoming.As such, no particular church can claim to have a monopoly on the church of Christ.
(2) Churches are realized both ad intra and ad extra symbolically and, as such, each particular church brings about the justifying grace of God within the diversity of concrete circumstances of the world.(3) There is a preexistent unity among churches despite the present state of visible disunity.(4) The unity that the church strives to realize has a vertical and horizontal dimension.The church endeavors to unite all of humanity with God.Thus, the church is a communion of human beings in communion with God.
Jeannine Hill Fletcher provides a valuable summary of Rahner's understanding of unity and difference and the significance of their interrelated roles within ecumenism.She writes: . . . in the ecumenical process, Rahner saw difference as a valuable quality reflecting the diverse receptions of God's presence in Christ.Here "the treasure of all the churches together is not only quantitatively but qualitatively greater than the actual treasure that can be found in a single church."The particularities engendered by different sociological configurations of Christianity are to be preserved as valuable in their distinctiveness.This principle of ecumenism is a theological principle born of a sociological reality.(Fletcher 2000, p. 189) For Rahner, ecumenism does not realize its goal by conforming to any one particular church, nor by an uncritical acceptance of difference.Instead, ecumenism achieves its goal through the mutual recognition of churches as living in a unity permeated by the diversity of particularity.
Rahner's call for an ecumenical church that considers seriously unity-in-difference is outlined in Unity of the Churches: an Actual Possibility, which he co-authored with Heinrich Fries in 1983.Despite its complicated and mixed reception, the work represents an important insight into Rahner's theological vision of an ecumenical church.Acknowledging that most Christians would reject some or all of the theses as presented, Rahner and Fries maintain that the conditions for the unity of the churches can be realized in a relatively short period of time, "if one perceives that this unity is such a radical obligation coming from Jesus that one has the courage to postpone a number a significant scruples."(Fries and Rahner 1985, p. 7).The subsequent eight theses outlined by Fries and Rahner provide the conditions for church unity (Fries and Rahner 1985).Unity of the Church on the one hand is an optimistic appraisal of the possibility of church unity maintaining that the distinctiveness of particular Christian churches need not threaten the unity of the Church.On the other hand, the work provides a sharp critique of the tendency for churches to universalize their own particularity.
Unity of the Churches is in some sense the logical and practical culmination of Rahner's ecumenical theology.Far from an approach that looks for a least common denominator between churches, Unity of the Church imagines the Church united in faith and order and brought to expression within the socio-cultural and historical particularity of a church.

Conclusions
Rahner understands that discernment regarding the realities of unity and diversity and their relationship to one another is the central task of the ecumenical movement.However, he also understands that ecumenical discernment between separated Christians is a continuing task that takes place within the ever-unfolding mystery of God-a mystery that for Christians, is realized in and through the relationship to Jesus Christ.Rahner understands that the relationship between Christ and the Church is brought about and manifest within the unique circumstances of concrete communities and persons.Hence, the domain of ecumenical discernment cannot be reduced to uniformity of expression.Rahner explains: . . . it would be preposterous and un-Christian for the Christian churches simply to carry on, conservatively, in their traditional status quo . . . .They must be attuned to their times.This does not mean that everything is allowed, that alien fashions are arbitrarily accepted.It means an ever renewed and radical return to the innermost heart of the faith, to which both Christians and the churches must bear witness.Christians must become more Christian; then automatically they will come closer to each other.What is required is not a liberalizing diluting of Christianity into a worldwide humanism.(Rahner 1991b, pp. 84-85) Rahner's theology provides valuable resources for ecumenism by framing questions regarding essential unity and acceptable difference within the symbolic competence or better, symbolic faithfulness of churches and individual Christians in relation to Jesus Christ.Put another way, Rahner provides theological resources that push ecumenical reflection on unity beyond uniformity in and through concrete expression towards a symbolic unity that, within a variety of particularities, really brings to expression the presence of Christ.Hence, ecumenical unity, according to Rahner, is a symbolic function and is achieved in terms of particular churches becoming more effective symbols of Jesus Christ.