The Authority to Define New Dogma

The authority of the ecumenical councils — the great work of the Undivided Church from Nicaea (325) to Nicaea II (787) — is confessed across every tradition here addressed (see Layer 2 document 10, The Authority of Ecumenical Councils). So too is the principle that the Church’s theological understanding can mature and deepen over time through reflection, interpretation, and reception (see Layer 3 document 11, Approaches to Biblical Interpretation). What stands in dispute in this faultline is a narrower and sharper question: whether the Church today possesses authority to define as irreformable dogma truths not explicitly contained in the apostolic deposit but claimed to be implicit within it, and whether that authority is vested in an ecumenical council, in the consensus of the Body, or in the Petrine office exercised by the Bishop of Rome.

The Competing Claims

Roman Catholic

The Church possesses a living Magisterium empowered by the Holy Spirit to discern and define as binding dogma truths that are implicit in the apostolic deposit. Revelation closed with the death of the last apostle, but the Church’s understanding of that revelation deepens under the Spirit’s guidance. What was contained in seed grows into flower; what was held implicitly becomes explicit through dogmatic definition.

John Henry Newman’s Essay on the Development of Christian Doctrine (1845) provides the classical argument: authentic development preserves the original idea while drawing out its consequences, as the oak is contained in the acorn. The seven “notes” of genuine development (preservation of type, continuity of principles, power of assimilation, logical sequence, anticipation of its future, conservative action upon its past, chronic vigour) distinguish true development from corruption.

The Marian dogmas serve as test cases. The Immaculate Conception (Ineffabilis Deus, 1854) and the Assumption (Munificentissimus Deus, 1950) were defined as revealed truths, binding on all the faithful. Pius XII stated that the Assumption was “a truth revealed by God and contained in that divine deposit which Christ has delivered to His Spouse to be guarded faithfully and to be infallibly declared” (Munificentissimus Deus §12). The dogma was not invented in 1950; it was recognized as having been present in the faith of the Church from the beginning.

Vatican I teaches that the Holy Spirit was promised to the successors of Peter “not that they might by His revelation make known new doctrine, but that by His assistance they might inviolably guard and faithfully expound the revelation or deposit of faith delivered through the Apostles” (Pastor Aeternus, ch. 4). The authority is to define, not to create.

The International Theological Commission has further clarified: “There can be no simple identification between the sensus fidei and public or majority opinion” (Sensus Fidei in the Life of the Church, 2014 §118). The sensus fidelium — the faith-sense of the whole people of God — plays a role in the discernment of doctrine, and Pius XII consulted the world’s bishops on the Assumption before defining it. The process, Rome argues, was not unilateral in practice even if it was papal in authority.

Eastern Orthodox

Dogma is what the ecumenical councils defined. The Church does not define new dogma; she articulates what was always and everywhere believed. The seven ecumenical councils (Nicaea I to Nicaea II, 325-787) represent the fullness of dogmatic definition. While the Church’s theological understanding deepens, this deepening does not produce genuinely new doctrines but only clarifies what was always explicit in the apostolic tradition.

Vladimir Lossky insists that “the tradition of the Church is not a transmission of doctrines” but “the life of the Holy Spirit in the Church” (The Mystical Theology of the Eastern Church, ch. 1 [∗]). Tradition is a living reality, but its content does not expand beyond what the apostles delivered. Georges Florovsky speaks of a “neopatristic synthesis” that retrieves and reappropriates the patristic deposit rather than extending it (Ways of Russian Theology [∗]).

The Orthodox rejection of the Marian dogmas is not a rejection of Marian piety. The East venerates the Theotokos as Panagia (All-Holy) and celebrates her Dormition. But the dogmatic definition of these beliefs by a single bishop, without an ecumenical council, and binding on the universal Church, is ecclesiologically impossible. No human organ can unilaterally expand the boundaries of what must be believed for salvation.

Sergei Bulgakov and other modern Orthodox theologians have argued that the Immaculate Conception rests on an Augustinian framework of original sin that Orthodoxy does not share, making the dogma not merely unauthorized but theologically alien (The Burning Bush, 1927 — originally written as an Orthodox critique of the 1854 Roman dogma).

John Meyendorff presses the ecclesiological point: “The Orthodox Church knows no other way of defining dogma than through the consensus of the whole Church, expressed in ecumenical councils” (Byzantine Theology, ch. 6 [∗]). A definition imposed by one see, however venerable, lacks the conciliar authority that alone can bind the universal Church. The issue is not merely what was defined but how and by whom.

Protestant

Doctrine is limited to what Scripture teaches, either explicitly or by good and necessary consequence. The Westminster Confession articulates the principle: “The whole counsel of God concerning all things necessary for His own glory, man’s salvation, faith and life, is either expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture” (WCF 1.6).

The Reformation did not reject all post-apostolic theological development. The Reformers affirmed the Nicene Creed and Chalcedonian Christology as faithful expositions of Scripture. What they rejected was development that exceeds Scripture — that binds the conscience with doctrines that cannot be demonstrated from the biblical text. Luther at Worms: “Unless I am convinced by the testimony of the Scriptures or by clear reason… I cannot and I will not recant anything” (Luther’s Works 32:112-113 [∗]).

The Newmanian principle of development is itself the problem. If the Church may define as binding any doctrine that can be claimed as “implicit” in the deposit, then there is no principled limit to doctrinal expansion. The acorn-to-oak metaphor proves too much: an oak looks nothing like an acorn, and the claim that the Assumption was “always implicit” in the apostolic deposit is precisely the kind of claim that sola Scriptura exists to resist.

The Thirty-Nine Articles state: “Holy Scripture containeth all things necessary to salvation: so that whatsoever is not read therein, nor may be proved thereby, is not to be required of any man, that it should be believed as an article of the Faith” (Article VI).

Herman Bavinck represents the mature Reformed critique: development in understanding is inevitable and welcome, but development in content — the addition of new articles of faith not demonstrable from Scripture — is a category error. The Church may say the same thing with greater precision; she may not say new things and call them old (Reformed Dogmatics 1.15 [∗]).

Scriptural Warrant

Rome invokes:

• John 16:13 — “When the Spirit of truth comes, he will guide you into all the truth.” The Spirit’s ongoing guidance enables the Church to unfold the full implications of the deposit.
• 1 Timothy 3:15 — The Church is “a pillar and buttress of the truth.” The Church is not merely the recipient of truth but its guardian and authoritative interpreter.
• John 14:26 — “The Holy Spirit… will teach you all things and bring to your remembrance all that I have said to you.” Remembrance is not mere repetition but living appropriation.

Orthodoxy invokes:

• Jude 3 — “The faith that was once for all delivered to the saints.” The deposit is complete; hapax (“once for all”) means it is not supplemented.
• 2 Timothy 1:14 — “Guard the good deposit entrusted to you.” The mandate is to guard, not to expand.
• Galatians 1:8 — “Even if we or an angel from heaven should preach to you a gospel contrary to the one we preached to you, let him be accursed.” The apostolic message is normative and final.

Protestantism invokes:

• Deuteronomy 4:2 — “You shall not add to the word that I command you, nor take from it.”
• Revelation 22:18-19 — The warning against adding to or taking from “the words of the prophecy of this book.”
• Proverbs 30:5-6 — “Every word of God proves true… Do not add to his words, lest he rebuke you and you be found a liar.”
• Acts 17:11 — The Bereans “examined the Scriptures daily to see if these things were so.” Scripture is the norm by which all teaching is tested.
• 2 Timothy 3:16-17 — “All Scripture is breathed out by God… that the man of God may be complete, equipped for every good work.” If Scripture makes the believer complete, no supplementary dogmatic definitions are needed.

Both sides have genuine scriptural arguments. The dispute is not about whether Scripture is authoritative but about what kind of authority the Church possesses over and under the scriptural deposit. Rome reads the “guiding into all truth” as a pneumatological mandate for doctrinal unfolding; Orthodoxy and Protestantism read “once for all delivered” as a pneumatological boundary marker. The Spirit is invoked by all; the question is whether the Spirit opens new rooms in the house or only illuminates rooms already furnished.

Historical Development

The early Church developed doctrine without a formal theory of development. The Nicene homoousion (325) was not found verbatim in Scripture; it was a theological term adopted to safeguard biblical truth against Arius. No one at Nicaea claimed to be defining new doctrine; they claimed to be articulating what the apostles had always taught.

The patristic period operated with what might be called an implicit theory of explication: the Church draws out what is contained in the apostolic preaching. Vincent of Lerins (c. 434) formulated the classical test: “what has been believed everywhere, always, and by all” (Commonitorium 2.6). But Vincent also allowed for profectus fidei — progress in understanding — provided it remained “in the same doctrine, in the same sense, and in the same meaning” (Commonitorium 23.28).

The medieval West saw doctrinal definitions accumulate: transubstantiation (Fourth Lateran Council, 1215), the seven sacraments (Council of Florence, 1439), the doctrine of purgatory (councils of Lyons and Florence). These were understood not as new doctrines but as authoritative clarifications of what the Church had always believed. Each definition, however, made the body of binding dogma larger than it had been before — and each was made without the participation of the East.

The East, meanwhile, made no comparable definitions after 787, though the Hesychast Councils of 1341-1351 defined the essence-energies distinction for Orthodoxy. The contrast is instructive: the West’s dogmatic output accelerated across the medieval period while the East’s froze. This divergence in practice reflects the underlying divergence in principle — whether the Church can and should continue to define, or whether the age of definition is essentially closed.

The crisis came in the nineteenth century. Newman’s Essay on Development (1845) provided a systematic justification for doctrinal growth. Pius IX defined the Immaculate Conception in 1854 without a council, by papal authority alone. Vatican I (1870) defined papal infallibility, establishing that the Pope can define dogma ex cathedra without conciliar consent. Pius XII defined the Assumption in 1950, the most recent exercise of this authority.

The Reformation had already drawn the line. The Lutheran and Reformed confessions of the sixteenth century established sola Scriptura as the formal principle: no authority can bind the conscience beyond what Scripture teaches.

The chronology matters. Before 1854, no Pope had ever unilaterally defined a dogma. The Immaculate Conception was the first exercise of the extraordinary papal Magisterium acting alone, without a council, to bind the universal Church to a new article of faith. The definition of papal infallibility at Vatican I (1870) was, in part, a retroactive justification of what had already been done in 1854. The Assumption (1950) confirmed the pattern. For Orthodoxy and Protestantism, the trajectory is alarming: from no unilateral definitions to three in under a century, with no principled limit on what might come next.

The Precise Point of Incompatibility

Strip away the agreements — all sides affirm a closed deposit of revelation, all affirm that the Church teaches with authority, all affirm that understanding deepens over time — and the irreducible contradiction is this:

Rome claims the authority to define as binding dogma truths not explicitly contained in Scripture or the unanimous witness of the early Church, on the grounds that they were implicitly present in the deposit. The Assumption is the clearest case: it is not taught in Scripture, was not universally believed in the early Church, and was defined by papal authority without a council.

Orthodoxy and Protestantism deny that any such authority exists — Orthodoxy because dogmatic definition requires conciliar consensus, Protestantism because doctrine must be demonstrable from Scripture.

If Rome’s authority is genuine, then the Assumption is a truth that all Christians are bound to receive. If it is not, then the Assumption is a pious belief that has been illegitimately elevated to the status of dogma, and the mechanism that elevated it — the very principle of authoritative dogmatic development — is itself in error.

This is not a dispute about Mary. It is a dispute about the nature of doctrinal authority itself. The Marian dogmas are symptoms; the disease (or the health, depending on one’s perspective) is the claimed power to define.

A further sharpening: Rome holds that a dogma defined by the Pope ex cathedra is irreformable “of itself, and not from the consent of the Church” (ex sese, non autem ex consensu Ecclesiae — Vatican I, Pastor Aeternus, ch. 4). Orthodoxy holds that no definition is valid without reception by the whole Church. The Protestant confessions hold that no definition is valid without demonstration from Scripture. These three criteria of validity are mutually exclusive in the hard cases.

Convergence Already Achieved

Vatican II’s Dei Verbum (1965) moved toward a more restrained understanding of the relationship between Scripture and Tradition: “Sacred tradition and Sacred Scripture form one sacred deposit of the word of God, committed to the Church” (DV §10). The emphasis on Scripture’s primacy within the deposit represents a development from the impression left by Trent’s “two source” language.

The Congregation for the Doctrine of the Faith has clarified that not all papal statements are infallible and that the category of infallible definitions is narrow. The distinction between definitive dogma and reformable doctrine has been developed (Mysterium Ecclesiae, 1973; Ad Tuendam Fidem, 1998), creating theological space for honest disagreement about non-infallible teaching.

The Joint International Commission for Theological Dialogue between the Roman Catholic Church and the Orthodox Church, in the Ravenna Document (2007), affirmed that “primacy and conciliality are mutually interdependent” (§43). Paragraph 43 continues: primacy at the local, regional, and universal levels “must always be considered in the context of conciliality, and conciliality likewise in the context of primacy.” This represents a step toward addressing the structural question of whether primacy can act without conciliarity.

The Lutheran-Roman Catholic Joint Commission’s Church and Justification: Understanding the Church in the Light of the Doctrine of Justification (1993; English 1994) addressed the relationship between Scripture, Tradition, and Magisterium, finding significant convergence on the servant role of the Magisterium under the Word, while acknowledging that the binding character of post-apostolic dogmatic definitions remains contested.

These are real achievements. But they have not resolved the central question: can the Pope define dogma that binds the universal Church without a council, and can such definition introduce genuinely new content? The achievements concern the process of definition; the underlying claim to authority remains contested.

The Groupe des Dombes, an unofficial French-speaking ecumenical group, has produced notable work on authority in the Church, including “Un seul Maître”: L’autorité doctrinale dans l’Église / One Teacher: Doctrinal Authority in the Church (Bayard, 2005; ET Catherine Clifford, Eerdmans, 2010), which explored the possibility of a Petrine ministry of unity exercised within conciliar constraints — a model that neither Rome nor Orthodoxy has officially adopted but that maps the terrain of possible convergence.

What Reconciliation Would Require

What it would cost Rome: A more rigorous distinction between irreformable dogma and reformable doctrine, applied retroactively. Rome would need to acknowledge — more clearly than it yet has — that the mode of definition matters, that papal definition without broad ecclesial reception is problematic, and that the sensus fidelium is not merely consulted but constitutive. The most painful question: could Rome acknowledge that the Marian dogmas, while true expressions of piety, were defined prematurely — before the conditions for a genuinely ecumenical definition existed? This would not require Rome to say the dogmas are false, but it would require saying that the act of definition outran the Church’s common discernment. This costs Rome its confidence in the sufficiency of papal authority alone.

What it would cost Orthodoxy: An honest reckoning with the fact that the conciliar model has not functioned since 787. If no ecumenical council can be convened without both East and West, and none has been convened in over twelve centuries, then the conciliar mechanism is effectively frozen. Orthodoxy would need to articulate how doctrinal questions are to be resolved in the absence of councils — and this articulation would itself be a development beyond the patristic model. Orthodoxy would also need to acknowledge that some of what it rejects in the Marian dogmas it already believes in practice: the Dormition is celebrated universally, and Mary’s sinlessness is confessed liturgically.

What it would cost Protestantism: An admission that sola Scriptura, taken strictly, cannot account for the doctrinal developments Protestantism itself accepts. The homoousion is not found in Scripture. The canon of Scripture is not established by Scripture. The doctrine of the Trinity, as formulated at Constantinople, requires the kind of theological reasoning that goes beyond “good and necessary consequence” from individual proof texts. If Protestantism accepts Nicaea as authoritative, it has already conceded that the Church has some authority to define doctrine in terms not found in Scripture. The question is not whether development occurs but how far it may go and who may authorize it.

Each tradition faces a real loss before it can receive what the others offer.

Rome loses the confidence that papal authority alone is sufficient. The ex sese of Vatican I — that papal definitions are irreformable “of themselves” — would need to be contextualized within a broader theology of reception, without being simply retracted. Whether this is possible without contradicting Vatican I is itself a controverted question within Catholic theology. Theologians such as Hermann Pottmeyer have argued that Vatican I’s definitions were left unbalanced by the council’s premature adjournment and that Vatican II’s emphasis on collegiality provides the needed complement (Towards a Papacy in Communion, 1998 [∗]). Others, including some within the CDF, have resisted this reading.

Orthodoxy loses the comfort of the conciliar ideal without facing its practical impossibility. The Holy and Great Council of the Orthodox Church (Crete, 2016) demonstrated both the potential and the difficulty: several autocephalous churches declined to attend, and its authority remains contested within Orthodoxy itself. If even an intra-Orthodox council cannot command universal participation, the prospect of a genuinely ecumenical council — East, West, and Protestant — is remote indeed.

Protestantism loses the clean simplicity of sola Scriptura as a self-contained system. The fragmentation of Protestantism into tens of thousands of denominations is not merely an organizational inconvenience; it is a theological problem. If Scripture is perspicuous and sufficient, why does it produce not one church but many? The standard Protestant answer — that the visible church is always semper reformanda and that unity is spiritual rather than institutional — has genuine force, but it does not fully account for the depth of Protestant disagreement on matters as fundamental as baptism, the Lord’s Supper, and ecclesiology itself.

These losses are genuine. They feel like surrender before they feel like gain. But the reconciling work of the Spirit has always felt that way — the cross before the resurrection.

For Further Study

• John Henry Newman, An Essay on the Development of Christian Doctrine (1845; revised 1878)
• Vincent of Lerins, Commonitorium (c. 434)
• Vladimir Lossky, The Mystical Theology of the Eastern Church (1944)
• Yves Congar, Tradition and Traditions: An Historical and a Theological Essay (1960)
• Aidan Nichols, From Newman to Congar: The Idea of Doctrinal Development from the Victorians to the Second Vatican Council (1990)
• Jaroslav Pelikan, The Christian Tradition, vol. 1: The Emergence of the Catholic Tradition (100-600) (1971)