The Rosetta Stone and Levels of Principled Inference to the Experience of Another Mind

Giulio Tononi; Kallum Robinson; Matteo Grasso; Naotsugu Tsuchiya

REVIEW 3 major objections 6 minor 6 references

The Rosetta Stone and Levels of Principled Inference to the Experience of Another Mind

T0 review · 3 major / 6 minor · reviewed 2026-08-16 · deepseek-v4-flash

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Pith's one-line read The paper argues that how much of another mind we can know is graded by how well its experience structure maps onto ours, from exact dictionary to nothing.

desk verdict A useful and honest conceptual framework for graded inference about other minds, whose central ladder is informally specified rather than derived — worth engaging, not yet a formal result. read the letter →

arxiv 2608.12030 v1 pith:TCAUX5WI submitted 2026-08-12 q-bio.NC

Kallum Robinson , Giulio Tononi , Naotsugu Tsuchiya , Matteo Grasso This is my paper · ORCID

classification q-bio.NC

keywords OtherMindsRosettaStoneQualiaStructureParadigmIntegratedInformationTheoryCategoryadjunctionacquaintancegapconsciousness

verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper argues that two structural theories of consciousness — Qualia Structure (Qstr), which characterizes a quale by its relations to all other possible experiences, and Integrated Information Theory (IIT), which conjectures that a single experience is its cause-effect structure — can, if their Rosetta Stones are valid, license principled inferences about another mind's experience. The strength of inference is graded by the level of category-theoretic correspondence between experiential structures: isomorphism gives a complete dictionary, strong adjunction gives an imperfect dictionary, weak adjunction gives only a grammar of experience, and no alignment terminates inference. Neither approach crosses the acquaintance gap, but alignment does shrink it by constraining which phenomenal attributions are warranted. The upshot is that structural approaches do not solve the problem of other minds; they convert it from an intractable skepticism into a graded system of constraints.

What carries the argument

The central object is the experiential category: a category whose objects are experiences (or points of a qualia structure) and whose arrows are graded relations such as similarity, inclusion, and association, with composition laws relaxed to inequalities in enriched categories. The mechanism that carries the argument is the functor between two such experiential categories, which acts as a dictionary; the round-trip behavior of the functor determines the level of inference — an isomorphism returns every object and arrow exactly, a strong adjunction returns a bounded near-approximation, a weak adjunction returns only the grammar of the other structure, and a failure of functorial alignment terminates inference. IIT contributes the cause-effect structure as the same kind of category, and its explanatory identity makes isomorphism of cause-effect structures sufficient for sameness of experience, while Qstr's relational web provides the necessary condition from the phenomenal side.

What would settle it

Compute structural alignment of color dissimilarity structures between two subjects: the paper predicts that an isomorphic alignment can only occur when the subjects' color experience is identical, so finding a near-isomorphic alignment between subjects known to differ in color experience, such as a dichromat and a trichromat, would falsify the isomorphism-to-identity step; alternatively, if two systems whose cause-effect structures do not align at all could still predict one another's similarity judgments perfectly, the claimed no-alignment limit would be broken.

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Extended reading notes

Core claim

The paper's central claim is that the acquaintance gap between minds is not an all-or-nothing epistemic wall: if a Rosetta Stone exists, the amount of inference about another mind's experience that is epistemically warranted is indexed by the category-theoretic strength of the correspondence between the two structures. Isomorphism, an exact round-trip mapping, would constitute a complete dictionary of experience and, under IIT, would certify identical experience. Strong adjunction delivers an imperfect dictionary that bounds the other's experience within a narrow domain, while weak adjunction returns only a grammar, telling us the kind of experience without its specific content. When no alignment exists, inference runs out, but it does so on principled grounds that are themselves informative. Qstr alignment is presented as a necessary condition for sameness of experience, while IIT's explanatory identity supplies sufficiency; together they determine what structural comparisons can and cannot support.

Load-bearing premise

The whole ladder of inference rests on the untested hypothesis that experiences genuinely form mathematical categories, with relations as arrows, and that IIT's cause-effect structures are categories too; if that hypothesis fails, the four levels are only a metaphor rather than a principled epistemic ranking.

Editorial extensions

If this is right

Under the paper's account, a validated Rosetta Stone turns 'what is it like to be you?' into a computable comparison: the more relations two experiential structures share, the narrower the class of experiences one can attribute to the other.
In the realistic cases of strong adjunction, we can infer the domain of another's experience, such as that the novice is tasting wine rather than coffee, without inferring the exact quale of that taste.
At the weak adjunction level, the paper licenses only kind-level attributions: we may say a bat's echolocation experience is space-like or time-like, but not what that space-like experience feels like.
If IIT's explanatory identity is correct, meaning in communication is the triggering of structurally similar cause-effect folds, making successful human communication an instance of strong adjunction between minds.
When no structural alignment exists, the principled conclusion is that no principled inference is available, which is itself a substantive epistemic result rather than a failure of the method.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

A testable extension the paper leaves implicit: the same four-level ladder could apply within a single subject across time, treating memory as a strong or weak adjunction between my current experiential structure and my past self's, which would bound how much we can know of our own past qualia.
The division of labor between Qstr's necessary condition and IIT's sufficient condition predicts that full cross-mind inference requires both behavioral qualia-structure alignment and substrate-based cause-effect alignment; a future study could check whether combining the two alignments improves cross-prediction of another's similarity judgments beyond either alone.
Applied to AI systems, the paper implies that a large language model whose dissimilarity structure aligns with a human's does not thereby warrant phenomenal attribution, because the model lacks a cause-effect structure in IIT's sense; the testable consequence is that behavioral alignment without substrate structure should not raise phenomenal confidence.

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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Desk Editor's Note

read the letter

Short version: this is a thoughtful, clearly-written chapter that gives structural theories of consciousness a usable vocabulary for talking about how much we can infer about other minds. The new bit is the strong-versus-weak adjunction distinction and the 'grammar vs dictionary' framing. It does not, as the authors know, give a formal derivation of those levels. The ladder is asserted, and footnote 4 admits that strong and weak adjunction are informal. That is a real limitation, not a fatal one, because the paper is honest about it and the examples carry the weight.

What it does well: it takes the adjunction hypothesis from Tsuchiya et al. and applies it systematically across cases (isomorphism, strong adjunction with sommelier/novice, weak adjunction with bat echolocation, no-relations with an alien). The Meroitic example for grammar is apt. The paper is careful to say that none of this closes the acquaintance gap, and it doesn't pretend IIT or Qstr have already been validated. The section on validation is a reasonable summary, not a stretch.

Soft spots: as the stress-test note says, the levels are not derived from category theory. 'Strong' and 'weak' adjunction are used loosely, with no measure of how far unit/co-unit depart from isomorphisms. 'No relations' isn't a category-theoretic notion at all; it's just the absence of a correspondence. So the promised 'levels of principled inference' are a plausible taxonomy, not a theorem. The category hypothesis (qualia structures and cause-effect structures are categories) is load-bearing and asserted with references, not established. If that fails, the whole ladder is metaphorical. The paper flags both issues, which counts for something, but it doesn't solve them. Also, the step from 'shared relations constrain experience differences' to 'strength of inference = level of structural correspondence' is argued by intuition, not derived. For a chapter, that's acceptable; for a formal framework, it's a gap.

Who it's for: philosophers and consciousness researchers working on structural approaches, especially anyone using Qstr, IIT, or category theory in cognitive science. It's a good conceptual backdrop for empirical work on Gromov-Wasserstein alignment of qualia structures, and it gives that work a principled-sounding interpretation. It would benefit from a formal treatment of adjunction strength, but the paper is worth engaging with as is.

Recommendation: send it to peer review. A serious referee could push the authors to either formalize the adjunction strength measure or more carefully limit the claims to a conceptual scaffold. The paper is honest, relevant, and unlikely to mislead if read carefully.

Referee Report

3 major / 6 minor

Summary. The paper addresses the classical problem of other minds in the context of structural approaches to consciousness. It examines two frameworks—the Qualia Structure paradigm (Qstr) and Integrated Information Theory (IIT)—and asks what can be inferred about another subject's experience if either framework succeeds in providing a 'Rosetta Stone' that translates experience into a mathematical structure. The central proposal is that the strength of warranted inference across minds is graded by levels of category-theoretic correspondence between the structures associated with each experience: isomorphism, strong adjunction, weak adjunction, and finally a 'no relations' limit where inference runs out. The paper argues that even though neither framework crosses the acquaintance gap, these levels provide principled constraints on phenomenal attribution. The argument is explicitly conditional on the existence of a valid Rosetta Stone and on the hypothesis that qualia structures and IIT cause-effect structures are themselves categories.

Significance. If the proposed hierarchy can be made precise, this would be a valuable contribution to both philosophy of mind and consciousness science, offering a middle ground between the all-or-nothing skepticism of the other-minds problem and the strong claim that the problem is fully solved. The paper is honest about its conditionality, uses apt and vivid examples (Russian blues, the sommelier and novice, the bat, Meroitic grammar), and connects the conceptual framework to ongoing empirical work such as Gromov-Wasserstein alignment of qualia structures and PCI-based validation of IIT. Its strengths include a clear separation of acquaintance from structural alignment, an explicit acknowledgment that structural correspondence does not transmit acquaintance, and a careful treatment of the epistemic limits of each level. At the same time, the central identification of inference strength with category-theoretic correspondence is asserted rather than derived, and the key formal notion of 'adjunction strength' is explicitly conceded to be informal. The paper is best read as a conceptual taxonomy and a research program rather than as a finished formal derivation.

major comments (3)

[§5.2, especially footnote 4] The central ladder from isomorphism through strong and weak adjunction to 'no relations' is not derived from category theory. Footnote 4 concedes that 'strong' and 'weak' adjunction are used 'in an informal, non-category-theoretical sense,' and no formal measure is given for how far the unit and co-unit of an adjunction depart from being isomorphisms. Without such a measure, the gradient from isomorphism to adjunction to 'no relations' is an illustrated taxonomy rather than a principled hierarchy, which undercuts the Abstract's claim that 'we identify the strength of inference with the levels of structural correspondence in Category Theory.' The authors should either supply a formal definition of adjunction strength (for example, via a metric on unit/co-unit components or a categoricity measure) or explicitly reframe the proposal as a heuristic taxonomy whose hierarchy is motivated by examples rather than derived from category theory.
[§2, hypothesis 'that both qualia structures and cause-effect structures (from IIT) are themselves categories'] This hypothesis is load-bearing but is asserted rather than established. For dissimilarity-based qualia structures, the paper itself notes in footnote 13 that similarity does not compose in an ordinary category and that enriched categories are required, so the category structure of Qstr is not immediate. For IIT cause-effect structures, no explicit construction of objects, arrows, and composition is provided. If this hypothesis fails, then isomorphism, adjunction, and 'no relations' are not a principled ladder of epistemic warrant but only a metaphor. The paper should either provide the categorical constructions for both Qstr and IIT structures, or state clearly that the entire argument is conditional on an open mathematical hypothesis and specify what empirical or theoretical evidence would support it.
[§5.3, 'No relations'] The claim that the structures themselves 'tell me that no inference is licensed' is not category-theoretically well-defined because between any two categories there is always at least a constant functor. Without a criterion for what counts as a relevant or non-trivial structure-preserving correspondence, the 'no relations' level is indistinguishable from a failure of the analyst to find a correspondence, and therefore does not constitute a principled limit. The authors should define 'no alignment' in a way that excludes trivial or degenerate functors, or explicitly present this level as an epistemic limit relative to the available Rosetta Stone rather than a categorical relation.

minor comments (6)

[§5.2.2, paragraph on the bat] The text says 'likely share very few relations in our experience of a tree (Figure 3C)', but Figure 3 shows the sommelier/novice wine example; the bat example is illustrated in Figure 2C. The cross-reference should be corrected.
[Footnote 13] The phrase 'each language (English and Russian) must be construed as one' is confusing; it should say 'as one enriched category' rather than 'as one', since the point is that the language is formalized as a single enriched category.
[Throughout] The acronym 'Qstr' is spelled inconsistently as both 'Qstr' and 'QStr' (e.g., in the Abstract and Section 3); the authors should standardize the capitalization.
[Figure 2 caption] The caption is extremely dense and relies on color conventions that may not be fully legible in print or for color-blind readers; a separate legend or a simplified caption would improve accessibility.
[§2, sentence beginning 'With a Rosetta stone'] The sentence 'such a solution to Other Minds would deliver a complete dictionary of experience between us' is later qualified in §5.1 as applying only to the isomorphism case; the earlier wording should be explicitly flagged as the idealized upper bound to avoid overstatement.
[§5.2.1, sentence 'the sommeliers should map down onto the novice'] This sentence contains a typographical error: 'the sommeliers' should be 'the sommelier's structure' or similar, and the sentence should be rephrased for clarity.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the paper's inference ladder is explicitly conditional on stated hypotheses and self-citations, not a derivation that reduces to its own inputs.

full rationale

The paper contains no fitted parameters, no empirical predictions re-described as derivations, and no known result merely renamed. Its central claim is conditional: if Qstr or IIT supplied a Rosetta Stone, and if qualia structures and cause-effect structures are categories, then structural correspondences (isomorphism, strong/weak adjunction, non-alignment) would constrain what one may infer about another mind. Section 2 explicitly labels the category assumption a "hypothesis" and cites prior work for it, rather than presenting it as an established theorem. Section 5.1 gives a non-circular rationale: because a quale is characterized by its relations to all other qualia, a structure-preserving mapping preserves quale identity only to the extent that it preserves those relations; hence the amount of preserved structure limits warranted phenomenal attribution. Footnote 4 concedes that "strong" and "weak" adjunction are used "in an informal, non-category-theoretical sense," and Section 5.3 treats "no relations" as a principled limit where inference runs out. These are limitations in precision and grounding, not circularity: the ladder is not obtained by defining the conclusion into the premises. The self-citations (Tsuchiya et al., 2016, 2023, 2025; Zaeemzadeh and Tononi, 2024) supply the background frameworks and are flagged as conjectural; no uniqueness theorem is invoked to forbid alternatives. The validation section cites external empirical tests (PCI, TMS, grid-neuron lesions) that do not reduce to the paper's own stipulated levels. Overall, the derivation chain is self-contained in the sense of being explicitly conditional and conceptually transparent, so no circular step is exhibited.

Assumptions & free parameters 0 free parameters · 4 assumptions · 0 invented entities

No numerical constants are fitted anywhere; the paper is conceptual and contains no empirical estimation. The relevant burden is carried by the assumptions listed, all of which are either stated hypotheses of the structural theories or interpretive postulates introduced to link category theory to epistemic inference.

assumptions (4)

domain assumption Qualia structures and cause-effect structures are categories in the category theory sense.
Section 2 states the whole inference-level scheme is 'contingent on the hypothesis' that both structures are categories. If false, the levels lose their formal grounding.
domain assumption IIT's explanatory identity: every property of experience is accounted for by a property of the unfolded cause-effect structure.
Section 4 and Section 5.2.1 use this conjecture to convert structural alignment into certification of same experiential kind. It is explicitly a conjecture, not a proven result.
domain assumption Qstr's relational characterization: a quale is exhaustively fixed by its relations to all other qualia, guided by the Yoneda lemma.
Section 3 says a sufficiently rich web of relations would fix the mapping one-to-one. This is an assumption about experience, not a theorem.
domain assumption Category-theoretic correspondence is an adequate measure of epistemic warrant for inferences about another mind.
Throughout Section 5, the mapping from structural preservation to inferential strength is presented by analogy (dictionary, grammar). This is the central conceptual assumption; footnote 4 concedes the adjunction terms are used informally.

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Cite this review

Pith. "Pith review of The Rosetta Stone and Levels of Principled Inference to the Experience of Another Mind." pith.science (2026). https://pith.science/paper/TCAUX5WI

@misc{pith2026260812030,
  author       = {Pith},
  title        = {Pith review of: The Rosetta Stone and Levels of Principled Inference to the Experience of Another Mind},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/TCAUX5WI}},
  note         = {Machine review of arXiv:2608.12030}
}

read the original abstract

The classical problem of Other Minds has dogged philosophers for millennia; asking if we have any way to truly understand the experience of another mind. We know our own intrinsic experience by acquaintance, but can only ever hope to possess an extrinsic description of another's, with the two separated by an acquaintance gap. Structural approaches aim to characterise experience in terms of a mathematical structure, and promise a 'Rosetta Stone'; that is, a principled method to translate the contents of experience into a mathematical structure. In this chapter, we examine two such approaches - the Qualia Structure Paradigm (Qstr) and Integrated Information Theory (IIT) - to ask what, if anything, they allow us to infer about another mind should they possess the Rosetta Stone they seek. Qstr proceeds inter-phenomenally; aiming to exhaustively characterise an experience by its relations to all other experiences and providing a necessary condition on the sameness of experience. IIT proceeds intra-phenomenally; conjecturing that a single experience is accounted for by the cause-effect structure unfolded from a substrate in a state, an explanatory identity that is both necessary and sufficient for the sameness of experience. While neither approach can cross the acquaintance gap to another's mind, they provide a common formal medium through which minds may be compared and in turn reduce the size of this gap. We identify the strength of inference with levels of structural correspondence in Category Theory. These descend from isomorphism through strong and weak adjunction, to a principled limit where inference runs out. We conclude that these structural approaches and the existence of their respective Rosetta Stones would not solve the problem of Other Minds, but instead provide a system of principled constraints on what we may infer, which is far more than what has been justifiable before.

Figures

Figures reproduced from arXiv: 2608.12030 by the authors.

**Figure 1.** Difference in intra- and inter-phenomenal approaches to the Rosetta Stone. 9 5. Levels of Inference to Another Mind. 10 5.1 Isomorphism 11 [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗

**Figure 1.** Difference in intra- and inter-phenomenal approaches to the Rosetta Stone. Broadly speaking, both Qstr and IIT seek a Rosetta stone, that is, a principled method by which to translate experience (acquaintance) into a mathematical structure (a description), yet do so from different directions. Qualia structure captures the relations between individual experiences (inter-phenomenal). These structures capture the relat… view at source ↗

**Figure 2.** Levels of Principled Inference in Comparing Experiential Structures. [PITH_FULL_IMAGE:figures/full_fig_p013_2.png] view at source ↗

Figures from the paper (1 more)

**Figure 3.** Figure 3: Theoretical difference in structure between novice and sommelier’s experience [PITH_FULL_IMAGE:figures/full_fig_p016_3.png]

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Reference graph

Works this paper leans on

6 extracted references · 5 canonical work pages

[1]

Berlin School of Mind and Brain, Faculty of Philosophy, Humboldt-Universität zu Berlin, Berlin, Germany. 2. Department of Psychiatry, University of Wisconsin-Madison, Madison, U.S.A. 3. School of Psychological Sciences, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia. 4. Advanced Telecommunications Research Computa...

work page
[2]

These qualitative contents of experience, also known as qualia,1 are precisely ‘what it is like’ to be oneself in a given moment

Introductions and the Problem of Other Minds Can we hope to truly understand what another person experiences? Even accurately expressing the contents of our own conscious experience is a task of monumental difficulty (Nagel, 1974). These qualitative contents of experience, also known as qualia,1 are precisely ‘what it is like’ to be oneself in a given mom...

work page 1974
[3]

the having is the knowing

Understanding the Need for a Rosetta Stone Before outlining how structural approaches can be used to address the problem of Other Minds, it helps to draw a distinction here owing to Russell (1912), between knowledge by description — the sort we gain from a third-person specification— and knowledge by acquaintance— the sort of first-hand knowledge we gain ...

work page 1912
[4]

The Qualia Structure Paradigm’s Rosetta Stone The Qualia Structure paradigm aims to characterise a quale by its relations to all other qualia (Tsuchiya and Saigo, 2021; Tsuchiya, 2025). Across the realm of colour experiences for example, the narrower quale of red’s redness is characterised partly by its more similar relation to the orangeness of orange th...

work page 2021
[5]

round trip

Levels of Inference to Another Mind If correct, QStr and IIT allow us to characterise our own experience in systematic, structural terms (i.e., construct a Rosetta Stone). So how could we use them to say something about another’s experience? As laid out in §2, the answer depends on how closely another mind’s corresponding mathematical structure aligns wit...

work page 2023
[6]

red” your “red

Validating the Construction of a Rosetta Stone Each claim we make above (§5) presupposes a valid Rosetta stone. So how can we be sure of having one in the first place? Any account of experience must be validated on ourselves (who are uncontroversially capable of conscious experience) first, and then be extended to the more complex cases we present here. G...

arXiv 2023

Pith tools

Reviewed August 16, 2026 · model on record in the stance chip above.

[1] [1]

Berlin School of Mind and Brain, Faculty of Philosophy, Humboldt-Universität zu Berlin, Berlin, Germany. 2. Department of Psychiatry, University of Wisconsin-Madison, Madison, U.S.A. 3. School of Psychological Sciences, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia. 4. Advanced Telecommunications Research Computa...

work page

[2] [2]

These qualitative contents of experience, also known as qualia,1 are precisely ‘what it is like’ to be oneself in a given moment

Introductions and the Problem of Other Minds Can we hope to truly understand what another person experiences? Even accurately expressing the contents of our own conscious experience is a task of monumental difficulty (Nagel, 1974). These qualitative contents of experience, also known as qualia,1 are precisely ‘what it is like’ to be oneself in a given mom...

work page 1974

[3] [3]

the having is the knowing

Understanding the Need for a Rosetta Stone Before outlining how structural approaches can be used to address the problem of Other Minds, it helps to draw a distinction here owing to Russell (1912), between knowledge by description — the sort we gain from a third-person specification— and knowledge by acquaintance— the sort of first-hand knowledge we gain ...

work page 1912

[4] [4]

The Qualia Structure Paradigm’s Rosetta Stone The Qualia Structure paradigm aims to characterise a quale by its relations to all other qualia (Tsuchiya and Saigo, 2021; Tsuchiya, 2025). Across the realm of colour experiences for example, the narrower quale of red’s redness is characterised partly by its more similar relation to the orangeness of orange th...

work page 2021

[5] [5]

round trip

Levels of Inference to Another Mind If correct, QStr and IIT allow us to characterise our own experience in systematic, structural terms (i.e., construct a Rosetta Stone). So how could we use them to say something about another’s experience? As laid out in §2, the answer depends on how closely another mind’s corresponding mathematical structure aligns wit...

work page 2023

[6] [6]

red” your “red

Validating the Construction of a Rosetta Stone Each claim we make above (§5) presupposes a valid Rosetta stone. So how can we be sure of having one in the first place? Any account of experience must be validated on ourselves (who are uncontroversially capable of conscious experience) first, and then be extended to the more complex cases we present here. G...

arXiv 2023