Often in conversations about the papacy and sola scriptura, you’ll hear the reassurance: “We’re not charismatics. Bishops don’t receive new prophecy. We can’t just invent doctrine—we only clarify what was already contained in the apostolic deposit.” It’s meant to dissolve the dispute before it even begins, as if denying “new prophecy” automatically secures everything else. But that’s precisely what needs to be tested.

Because Rome and Orthodoxy routinely rely on a third category—a tertium quid: not “new revelation,” yet still capable of producing new, irreformable, conscience-binding determinations that were not previously publicly binding as divine truth.

Once you press the logic, that middle category can’t hold.

1) What is Revelation?

The faith operates by receiving divine speech:

• God’s direct self-disclosure (theophany),
• God authorizing agents to speak for him (“Thus says the LORD”),
• and God inspiring writings as his public testimony.

God makes himself known, and he makes known that he has made himself known. That’s what makes divine revelation the kind of thing that can bind the conscience universally.

Divine revelation, in the strict sense, is not merely any true statement about God, nor any event God providentially permits, but a divine communicative act. The necessary and sufficient conditions are these: there must be a message from God—God must be the ultimate source of the content—and God must intend that content to be received as his own speech, his own self-disclosure, rather than as a merely human judgment that happens to be correct. Further, God must authorize the medium by which the message comes (whether theophany, vision, sign, prophet, apostle, or inspired writing) such that it functions as an instrument of divine speech. And because God cannot lie or mislead in what he intends to teach, divine revelation carries a built-in truth-guarantee: God so ordains and superintends the communicative act that what is revealed—what God intends to assert or disclose—is infallibly true. In short, revelation is “divine speech” precisely because God is its source, God intends it as his speech, God authorizes the means of its delivery, and God guarantees the truth of what is thereby disclosed.

Start with the necessary and sufficient conditions for divine revelation as such. At minimum, divine revelation is propositional content that God intends to communicate, such that God so ordains the means of communication that the message is infallibly true. Notice that nothing in that definition requires the revelation to be public; God can reveal truly to an individual (e.g., in a dream) without thereby establishing a rule binding on the whole church. But once you define revelation in terms of God’s ordaining speech to be infallible, the Rome/EO claim becomes unstable: their dogmatic “tradition” is said to be infallibly true and divinely protected, yet they insist it is not “revelation.” By what principled criterion is it not revelation, if the decisive mark of revelation is precisely God’s ordination/guarantee of infallible truth?

Divine revelation need not always take the form of bare propositions. God can reveal himself through acts, signs, historical events, theophanies, visions, and providential interventions—modes that are not, in themselves, “sentences.” But the moment such revelation is used to ground doctrine, it must be cognitively determinate in a way that can be expressed as a truth-claim (even if only implicitly): this act means X; God thereby teaches Y; therefore Z is to be believed/obeyed. In other words, non-propositional revelation can exist, but it cannot function as a rule of faith without becoming propositionally articulable at the level of doctrine. And that is exactly where the tertium-quid problem reappears for Rome/EO: their “infallible tradition” is not merely a set of non-propositional ecclesial practices; it is a stream of determinate doctrinal judgments that claim divine guarantee. If “divine guarantee of truth” is sufficient to categorize something as revelation (whether originally propositional or not), then they owe a principled, non-circular demarcation between “God speaking” and “the church speaking infallibly.”

Rome/EO effectively grant that the church can issue propositionally articulable theological judgments—content that must be believed, is divinely sanctioned, and is irreformable. But that raises the obvious question: what is the relevant difference between that and divine revelation? If “revelation” is divine communication secured from error by God’s action, then a divinely protected dogmatic definition is, in substance, divine speech mediated through an institution. Calling it “assistance” rather than “revelation” does not change its functional role: it supplies binding divine truth to the church. So unless they can provide a principled demarcation (not a mere label), the tertium quid collapses—“infallible tradition” just is revelation under another name.

And notice the deeper irony. If the church’s charism is not merely that it repeats Scripture but that it can clarify Scripture by delivering infallible knowledge of God’s intent in the text, then the magisterial interpretation becomes epistemically superior to the written word itself. The words of God, on this model, are not sufficient to yield their own determinate doctrinal content without an additional infallible interpretive act. But then the decisive locus of divine authority shifts from the public text to the later institutional judgment that fixes its meaning. In that case, what you are ultimately obeying is not Scripture as such, but the church’s infallible meaning-conferral upon Scripture—which makes the church’s deliverance function even more like “the very words of God” than the words of God themselves, since it is the church’s act that renders them determinately knowable and binding.

A possible reply is to say: “It is only divine revelation when God intends the agent to speak for him as his Word.” Fine. But then the issue is whether Rome/EO claim God intends the Church to speak that way. And Rome, at least, plainly does. The whole point of an irreformable dogmatic definition is that the Church is not merely offering a fallible interpretation but delivering what must be believed on divine authority: Vatican I says papal ex cathedra definitions are “of themselves, and not by the consent of the Church, irreformable,” grounding this in “divine assistance” promised to Peter. Likewise, the Catechism teaches that when the Pope “proclaims by a definitive act” a doctrine of faith or morals, he “enjoys this infallibility,” and that such doctrine is proposed “for belief as being divinely revealed” and must be adhered to with “the obedience of faith.” Vatican II goes further: it says the task of “authentically interpreting the word of God, whether written or handed on” is entrusted to the Church’s living teaching office, which “draws from this one deposit of faith everything which it presents for belief as divinely revealed.” And Lumen Gentium states that bishops “speak in the name of Christ,” that the faithful are to adhere to their teaching with “religious assent,” and that conciliar “definitions must be adhered to with the submission of faith.”

So this “intention” criterion doesn’t actually demarcate revelation from “infallible tradition.” While in a certain sense all speech is “sanctioned” under providence (a divine author even writes the villain’s lines), there is a difference between mere providential permission and speech intended to deliver binding divine truth and doctrine to the church. But once the Catholic says, in effect, “God intends the Church’s definitive judgments to count as his own teaching,” the tertium quid collapses: you’ve reintroduced a continuing revelatory oracle—divine speech mediated through an institution—while insisting it is not “revelation” only by a verbal fiat.

2) The Infallible-Organ Dilemma

Now consider the claim Rome and Orthodoxy want to maintain: no new revelation, but also a living infallible organ (a council, a bishop, a pope, “the Church”) capable of issuing irreformable, conscience-binding dogmatic judgments.

If that organ can produce infallible, universally binding propositions, then one of two things must be true:

Option A: God is guaranteeing their speech as divinely authoritative

If the result is an infallible proposition that binds the whole church, then God is causing/guaranteeing the content in a way that makes it function as public divine speech.

But that reintroduces the prophetic category—divinely secured propositional output—while refusing to call it what it is. In other words: you have “no new prophecy,” but you still have a mechanism that yields infallible deliverances that bind consciences as divine truth.

That is a distinction without a difference.

Option B: God is not guaranteeing their speech as divine speech

Then the deliverance is not a new infallible public norm. It may be wise, traditional, influential—even highly authoritative in a ministerial sense. But it cannot bind consciences irreformably as divine truth.

So the “no new revelation” line doesn’t resolve the dispute. It only tries to invent a third category: not prophecy, not fallible teaching, but a mysterious kind of divinely guaranteed, universally binding speech that lacks the public conditions by which God ordinarily holds people accountable to his speech. That category is precisely what needs justification.

3) The Dogma-Content Dilemma

Even if you set aside the question of how the church speaks infallibly, the same instability appears in the content of dogmatic definitions.

Any dogmatic statement (“X is de fide”) falls into one of two categories:

(1) Already present and binding in public revelation before the definition

If the doctrine was already publicly revealed and binding prior to the definition, then the definition does not create a new obligation. It merely recognizes what was already binding.

But then the infallible organ is not a second rule of faith. It is at most a ministerial court claiming certainty. The binding force exists independently of the act. In that case, the “infallibility” claim is not doing the epistemic work people want it to do. It’s just an attempt to terminate dispute by fiat.

(2) Not already present and binding before the definition

If the doctrine was not already publicly identifiable as binding divine truth, then the definition supplies new conscience-binding content. Call it “development” if you like, but functionally it is a new public norm—“new revelation” in the only sense that matters for authority.

And then the question is unavoidable: by what public divine warrant does an institution possess the right to generate new irreformable obligations for the whole church?

4) The Tertium Quid and the Circularity

Rome and Orthodoxy try to avoid both horns by proposing a middle category:

• The definition supposedly adds no new content (so it isn’t revelation),
• yet it also yields more determinate, conscience-binding content than what was previously publicly available.

That is the tertium quid: clarification that binds as new while claiming it isn’t new.

But this only works if the church’s later act is what makes the content count as “implicit” in the first place. And if that’s the mechanism, the reasoning is circular:

• It’s apostolic because the church defines it as apostolic.
• It was always implicit because the church later made it explicit.
• It binds because the church says it binds, and the church can’t err because the church says it can’t err.

You have not provided a public divine warrant. You have merely elevated an institutional claim to the status of divine truth.

So here is the question that forces the tertium quid to pick a side:

Before the church defined X, was X already a publicly binding article of faith such that rejecting it was heresy in principle? Yes or no?

• If yes, then the definition is not needed as an infallible rule; public revelation already bound it.
• If no, then the definition adds a new binding object of faith.

Both Rome and Orthodoxy frequently appeal to Acts 15 as the model for how the Spirit continues to guide the Church in doctrinal decisions. But that appeal actually sharpens the problem rather than resolving it. In Acts 15 the apostles and elders issue a binding decree and explicitly frame it as Spirit-backed: “it seemed good to the Holy Spirit and to us.” Luke then records that event as part of inspired Scripture. In other words, the council’s judgment is not merely a wise ecclesial decision but a divinely secured deliverance that functions as part of God’s revelatory word to the Church. If Rome or Orthodoxy claim their councils or magisterial definitions are analogous—Spirit-guided in a way that produces irreformable, conscience-binding doctrine—then the analogy collapses their position into precisely the category they deny: ongoing revelatory speech mediated through the Church. But if they deny that later councils operate in the same revelatory manner as Acts 15, then the analogy fails, and those later decisions can only be fallible ecclesial judgments rather than infallible norms binding the whole Church. Either the Acts 15 model truly applies, in which case the tertium quid becomes continuing revelation, or it does not apply, in which case the claim of irreformable Spirit-guaranteed dogma loses its footing.