The Development of Doctrine

The Catholic Church teaches that doctrine develops. The apostolic faith was delivered once for all, complete, and the Church can add nothing to it. But the Church’s understanding of that faith grows: what was implicit becomes explicit, what was held without definition gets defined, and new words guard old truths. This is not a modern invention. It is the pattern of the councils, the teaching of the Fathers, and the explicit doctrine of St. Vincent of Lerins in the fifth century.

A Seed, Not a Statue

The classic image comes from John Henry Newman, who gave the modern theory of development its shape. Doctrine is like a seed, not a statue. A statue is finished at the casting; any change is damage. A seed is complete from the start, containing the whole plant in miniature, yet it must grow to become what it is. An acorn that never became an oak would not be faithfulness. It would be failure.

Newman was not inventing this. He was quoting St. Vincent of Lerins, who wrote around 434 in his Commonitorium. Vincent is famous for the canon: hold “that faith which has been believed everywhere, always, by all” (quod ubique, quod semper, quod ab omnibus creditum est). What is quoted less often is that Vincent immediately asked the obvious question: “shall there be no progress in Christ’s Church?” His answer:

“Certainly; all possible progress! For what being is there, so envious of men, so full of hatred to God, who would seek to forbid it? Yet on condition that it be real progress, not alteration of the faith. For progress requires that the subject be enlarged in itself, alteration, that it be transformed into something else.”

The Latin word is profectus: real development, the enlargement of one subject in the same sense and the same meaning. Vincent’s rule is not a freeze on the faith. It is a compatibility constraint. Growth is legitimate when it enlarges the same subject in the same sense. It is illegitimate when the subject is transformed into something else.

Software engineers already think this way. A library can ship new features in minor versions without breaking its public interface; the contract holds while the implementation grows. Vincent permits minor-version development. He forbids breaking changes. Or picture the Vincentian canon as a test suite: “believed everywhere, always, by all” is the existing suite for the faith. A legitimate development is a refactor that keeps every test green. The code changes, the understanding deepens, but no test that passed before may fail now. An illegitimate innovation is a commit that breaks the suite and then deletes the failing tests. The Catholic claim has always been exactly this: the doctrine grows in understanding while remaining the same doctrine, the same sense, the same meaning, with the whole suite still passing.

The First Millennium Practiced It

Both Catholics and Orthodox accept that the first thousand years developed doctrine, because the councils themselves did it. Nobody believes the apostles used the word homoousios. The Council of Nicaea in 325 defined that the Son is “of one substance” with the Father using a term found nowhere in Scripture, and the term was controversial precisely because it was new. Many bishops preferred biblical language. Nicaea chose the novel word anyway, because the old words had proven inadequate against Arianism.

The Council of Ephesus in 431 defined Mary as Theotokos, God-bearer. The title had older roots, but its dogmatic definition was a genuine advance: the Church had never before bound the conscience of the faithful to this precise Marian claim under anathema.

Chalcedon in 451 went further still. Its definition that Christ is one person (prosopon, hypostasis) in two natures (physeis) is built from the technical vocabulary of Greek philosophy. The Fathers took Aristotle’s toolbox and used it to say something the apostles never said in those terms. Whatever else development means, the first millennium practiced it, and both East and West receive those councils as binding.

So the real dispute was never whether doctrine develops. It is whether development continued after the great councils, by what means new definitions are recognized, and which ones are faithful. Those are serious questions. They deserve better than slogans.

How Development Actually Works: The Changelog

The master pattern is simple: the behavior ships first, and the spec gets written when a bug report forces it. The early church prayed for the dead centuries before Florence wrote the spec for purgatory. “Full of grace” is in Luke’s Gospel a thousand years before anyone defines the Immaculate Conception. The doctrine didn’t change between those dates. It went from running code to documented release. Development is the changelog of a stable system.

Most definitions are bug-driven. The annotation gets written when someone’s code breaks against the unwritten contract. Nobody needed Theotokos defined until Nestorius filed the bug report; then Ephesus added the compile-time assertion, and the assertion protected Christ’s type signature, not Mary’s resume. Nicaea’s homoousios is the same story: the old words proved inadequate against Arianism, so the council shipped a new term to guard the old faith. Definitions are patches, and patches have issue numbers.

Some developments are long-open pull requests. The Immaculate Conception sat as an open issue for a millennium: how is Mary sinless if all have sinned? Proposed answers kept failing the test suite. Then Duns Scotus submitted the PR that made everything pass: preservative redemption. Christ didn’t pull Mary out of the pit; he kept her from falling in. Input validation at the boundary instead of exception handling after the crash. Same test suite (universal sin, Christ the sole mediator), new code that finally satisfies it. The 1854 definition is the merge commit, not the first line of code (see the doctrine).

Some developments are conventions becoming specs. For centuries the church ran leadership on informal convention: Rome coordinates, and everyone knows it. Vatican I is the consensus paper, the formal spec written after centuries of running the protocol, the way the Raft paper specified leader election long after distributed systems were already electing leaders. Gallicanism and the nineteenth-century crises were the network partitions that made the informal version untenable. The protocol didn’t change. It got specified under pressure, which is when specs always get written (papal infallibility).

The git history view ties it together: one branch, no force-pushes, no rewritten history. Each definition is a commit responding to an issue. The tree keeps growing, every earlier commit still intact, and git log tells the whole story from the seed to the present. That is the development of doctrine: not a statue being chipped at, but a repo with a clean, unbroken history.

The Concern, Stated Fairly

The objection to development is not foolish, and it deserves a fair hearing. The Orthodox version draws the line between explication and innovation: making explicit what was always there is legitimate, adding something new is not. When Rome defined the Immaculate Conception in 1854, or when it teaches papal infallibility, many Orthodox see innovation: doctrines the first millennium never knew, imposed by an authority structure the first millennium never recognized. The Protestant version of the worry runs through sola scriptura: if the Church may define doctrines the apostles never stated, what stops her from adding to the Word of God?

The worry is legitimate because real corruptions have happened. Arianism was an innovation. Nestorianism was an innovation. The Church needed a way to distinguish growth from corruption, and the instinct to guard the deposit is a holy instinct. Catholics share it. The question is only how to tell the seed’s growth from a different plant, and who gets to say.

Growth on Both Sides of the Schism

Here the historical record offers something worth sitting with. The development Catholics describe in the West has a parallel in the East, and noticing it need not be a weapon. It can simply be honesty about how the Church, East and West, has always worked.

In the 1330s and 1340s, Gregory Palamas, a monk of Mount Athos, defended the hesychast practice of contemplative prayer against Barlaam the Calabrian. Barlaam argued that God is utterly unknowable and that the hesychasts’ claim to experience the uncreated light of Tabor was blasphemy. Palamas responded with a distinction: God is unknowable in his essence but truly knowable, and truly participated in, through his uncreated energies. The 1351 Synodal Tome affirmed this as a “real distinction” in the very being of God, while insisting it does not violate divine simplicity: “unity without confusion, distinction without division.”

Today this is Orthodox dogma, and Palamas is commemorated liturgically on the Second Sunday of Lent. But consider what it looked like at the time. Barlaam called it an innovation. Gregory Akindynos condemned the essence-energies distinction as a novelty and was excommunicated for it. Patriarch John XIV sided with the anti-Palamites and had Palamas imprisoned for four years. The controversy ran through a civil war, a change of emperors, and a change of patriarchs before the 1351 council settled it.

By every external measure, this is what development looks like: a disputed theological distinction, defended by argument, opposed by contemporaries as innovation, settled by conciliar authority centuries after the apostles. It introduced a real distinction in God, in the same register of speech as the Trinity and the distinction defended at Chalcedon, which no ecumenical council of the first millennium had defined, using philosophical precision the earlier Fathers had not used. If that is not development, the word has no meaning.

The git history is instructive:

# the claim, stated flatly: no commits to the doctrinal branch since the schism
# only the same tree checked out again and again

1351-synodal-tome:
    added: a real distinction in God (essence / energies)
    reviewed-by: contemporaries calling it a breaking change
    merged: over objection, as the rule of faith of the Orthodox Church

The Orthodox response is that Palamas explicated what the Fathers always taught, citing Dionysius, the Cappadocians, and Maximus. That may well be true. But notice the shape of the move: the claim that a new formulation draws out what was implicit. The Catholic makes exactly the same move about the Immaculate Conception drawing out what was implicit in “full of grace” (see the doctrine). If the category of legitimate explication does real work for Palamas, it cannot be fenced off from Catholic use by assertion alone. One standard has to apply on both sides.

The seventeenth century adds a second witness. The Synod of Jerusalem, convened by Patriarch Dositheus in 1672, issued a Confession refuting Calvinism article by article. To defend the real presence (the doctrine this site treats under transubstantiation), the synod taught the Eucharistic change using metousiosis, the Greek equivalent of the Latin transubstantiatio. It affirmed the seven sacraments, rejected justification by faith alone, and affirmed doctrines including a purgatory (purgatory) that sits uncomfortably with what many Orthodox say today.

There is a quiet irony here, and it cuts gently. The synod used precisely the scholastic philosophical vocabulary that critics of Catholic development treat as the mark of Latin corruption. In software terms, Dositheus imported a dependency from the Latin package ecosystem and shipped it in an official release. Then later Orthodox reception itself treated parts of Jerusalem 1672 as problematic: the Synod of Constantinople in 1691 pushed back against the Aristotelian detailing of the Eucharistic change. That is a revert of a dependency the previous release had added. Within the Orthodox tradition there is a post-schism council, a post-schism revision of that council’s philosophical method, and ongoing disagreement about how much of Dositheus binds. That is not a failure. It is a communion working out its faith over time, the same work the West knows.

Purgatory shows the same pattern from the other side. The observed behavior both communions share is ancient: Christians pray for the dead, and have since the catacombs. That is the API both forks implement. The West merged a detailed RFC: Florence and Trent specified the mechanism (purgation after death, the suffrages of the faithful aiding the departed). The East never merged the mechanism spec. Their RFC is still in draft. What the draft contains: the dead can be aided by prayer, there is an intermediate state, purification after death is real. What it does not contain: a specified mechanism, a quantified ledger, indulgences. Some Eastern contributors reference the toll-house tradition as an unofficial draft; others reject it outright, and there is no maintainer consensus. Jerusalem 1672 briefly shipped a purgatory clause, then later reception walked it back. The draft never got merged.

The irenic payoff matters more than the polemic one. The Catholic claim was never “adopt our implementation details.” It is that the merged spec is true. The East running the same API (prayers for the dead, aid for the departed) with an unmerged mechanism draft is not a contradiction of the Western spec. It is two forks interoperating at the API level while documenting internals differently. And the East’s restraint is a feature, not a bug: declining to spec what has not been revealed is exactly the humility the Vincentian test suite rewards. The real question between the forks is whether the West’s detailed spec overfits the data. That is a fair debate, and it is the one worth having.

The structural point is the simplest. Orthodoxy has no agreed account of which councils after the seventh are ecumenical. Some Orthodox count the Photian council of Constantinople (879-880) as the Eighth Ecumenical Council. Others point to the Hesychast councils of 1341 and 1351 as a ninth. There is no pan-Orthodox consensus, and no agreed authority to settle the question. A communion that presents itself as having preserved the faith unchanged cannot say with one voice which of its own post-schism councils carry ecumenical authority. Compare the Catholic position: a definite list of ecumenical councils, a definite authority that recognizes them, a definite theory of why the list can grow under that authority (papal infallibility). Whatever one thinks of the Catholic theory, it is a theory. The Orthodox position on post-schism development is, in practice, development without a theory of development.

The Contract and the Skin

One more distinction keeps the whole topic honest. Every doctrine has a defined core and an illustrative shell, and the shell is allowed to change. What Florence and Trent defined about purgatory is thin: it exists, the souls there are purified after death, and they are helped by the prayers of the faithful. That is the contract. Fire, levels, durations, all of it, that is the frontend skin the medievals rendered the contract in. The Catechism (1030-1032) speaks of purification and drops the fire language entirely. The API didn’t change. It got a new UI.

This is a general principle, and it disarms a whole class of objections. The dogma is the interface; the imagery is the skin. You can reskin purgatory as the deploy pipeline’s cleanup stage, the final sanitization before the release ships to prod, without breaking the contract. Confusing the two is how people end up defending the skin instead of the contract, which is the one failure mode development must never allow. The Vincentian test suite tests the contract. The skin is free to evolve.

One Standard for Both

This yields a conclusion that should chasten everyone, Catholics included. Take any criterion of illegitimate innovation strict enough to condemn Catholic development. Apply it to the essence-energies distinction: a real distinction in God, undefined by any of the seven councils, denounced as novelty by learned contemporaries, settled amid civil war. Apply it to Jerusalem 1672: scholastic terminology borrowed from the Latin West, later partially revised by a subsequent Orthodox synod. The criterion condemns these too. So either the criterion is miscalibrated, or it takes down Palamas and Dositheus with it, which no Orthodox wants.

Now take any criterion broad enough to vindicate Palamas: legitimate explication of the implicit, philosophical precision in service of the deposit, conciliar reception over time. That criterion must then be available to Catholic developments as well. The Catholic asks for no special exemption, only the same rules: that drawing out the implicit is explication, that new words can guard old faith, that the Church may define under pressure what she previously held without definition.

The honest debate, then, is about which developments are faithful and which are not. That debate requires criteria, evidence, and the humility to apply one’s own criteria to one’s own history. Catholics should feel the weight of that too. Development is not a license; it is a discipline, and every claimed development must show its work against the Vincentian test suite.

An Irenic Note

To Orthodox readers: none of this makes Palamas wrong. The essence-energies distinction may well be true, and the Catholic Church has never condemned it. In recent decades Catholic theologians have studied Palamite theology with genuine appreciation. The point of the history above is not that Orthodoxy innovated and is therefore false. It is that Orthodoxy grew, and is therefore in the same position as Catholicism: both communions must give an account of how the apostolic faith grows without breaking (the deposit of faith), and the account has to work for both sides (the broader history in the East–West schism).

To Protestant readers: the Catholic doctrine of development is not a blank check for invention. It is Vincent’s rule, that the subject be enlarged in itself and never transformed into something else, applied with the seriousness the Reformers themselves would demand. If a development cannot show its continuity with the apostolic deposit, it fails the Catholic test too.

We share more than the polemics suggest: the same Vincent, the same councils of the first millennium, the same desire to guard what was delivered once for all. The discussion can proceed on those terms, without either side claiming a changelessness that history does not support, and without either side treating growth as proof of corruption.

Cross-Links

This article reads best alongside:

• The Deposit of the Faith: what grows and what breaks
• The East–West Schism: the communion split this article examines
• The Filioque: the case’s archetypal “Latin addition”
• Nature vs. Person: the Chalcedonian semantic pair
• Transubstantiation: the term the Jerusalem synod Greeked as metousiosis
• Purgatory: affirmed by Jerusalem 1672 against its own later reception
• Papal Supremacy and Papal Infallibility: the authority questions at the center of the case

Sources

Primary documents cited above:

• St. Vincent of Lérins, Commonitorium (c. 434), ch. 2: the canon: quod ubique, quod semper, quod ab omnibus creditum est, and ch. 23: the profectus passage on “real progress, not alteration of the faith.”
• Council documents and their received formulas: Nicaea I (325, homoousios); Ephesus (431, Theotokos); Chalcedon (451, Definition in one person in two natures).
• Councils of Hagia Sophia, Constantinople (1341, 1351) and the accompanying Synodal Tome of 1351, which received the essence–energies distinction as Orthodox doctrine (“real distinction… unity without confusion, distinction without division”).
• Confession of Faith of the Orthodox Patriarch Dositheus, presented to the Synod of Jerusalem (1672): refutation of the Confession of Cyril Lucarius, affirming the seven sacraments and the real presence under the heading of metousiosis.
• Synod of Constantinople (1691): post-schism reception that walked back the Aristotelian detailing of the Eucharistic change in the Dosithean confession.

Secondary: John Henry Newman, An Essay on the Development of Christian Doctrine (1845): the seed-and-plant image and the theory of profectus systematized. Aidan Nichols’ scholarship on the post-schism councils and their contested status; the Orthodox-internal disagreement over the count of ecumenical councils is a matter of open literature.