pith. sign in

arxiv: 1907.06240 · v2 · pith:DJBDNADInew · submitted 2019-07-14 · 🪐 quant-ph

'Two Dogmas' Redux

Jeffrey Bub This is my paper

Pith reviewed 2026-05-24 21:39 UTC · model grok-4.3

classification 🪐 quant-ph
keywords Everett interpretationWigner's friendmodal contradictionsquantum interpretationsFrauchiger-Rennerencapsulated measurementsmany-worlds
0
0 comments X

The pith

The Everett interpretation leads to modal contradictions in Wigner's friend scenarios involving super-observers measuring observer memory.

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

The paper revisits an earlier information-theoretic view of quantum mechanics and argues that the Everett interpretation becomes inconsistent when applied to extended Wigner's friend experiments. In these setups a super-observer performs an unrestricted measurement on the internal memory of an observer who has already measured a qubit spin. The multiplicity of branches produces incompatible statements about what is possible or probable for the same physical event. A sympathetic reader would care because the result suggests the Everett view cannot maintain consistency without extra rules on how records or branches are defined. The argument follows the Frauchiger-Renner structure to reach this conclusion.

Core claim

Following Frauchiger and Renner, the Everett interpretation leads to modal contradictions in Wigner's-Friend-type scenarios that involve encapsulated measurements, where a super-observer measures the memory of an observer system after that system measures the spin of a qubit. In this sense, the Everett interpretation is inconsistent.

What carries the argument

Encapsulated measurements on observer memory in Wigner's friend scenarios, which generate modal contradictions when the Everett branching structure is applied without further stipulations.

Load-bearing premise

The described Wigner's-friend scenarios with unrestricted super-observer measurements on observer memory correctly instantiate the Everett interpretation without additional interpretive stipulations about branching or records.

What would settle it

A step-by-step assignment of possibilities within the Everett framework for the full sequence of qubit measurement followed by super-observer memory measurement that yields no contradictory modal claims.

read the original abstract

About ten years ago, Itamar Pitowsky and I wrote a paper, 'Two dogmas about quantum mechanics,' in which we outlined an information-theoretic interpretation of quantum mechanics as an alternative to the Everett interpretation. Here I revisit the paper and, following Frauchiger and Renner, I show that the Everett interpretation leads to modal contradictions in 'Wigner's-Friend'-type scenarios that involve 'encapsulated' measurements, where a super-observer (which could be a quantum automaton), with unrestricted ability to measure any arbitrary observable of a complex quantum system, measures the memory of an observer system (also possibly a quantum automaton) after that system measures the spin of a qubit. In this sense, the Everett interpretation is inconsistent.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript revisits the authors' prior 'Two dogmas about quantum mechanics' paper and, following Frauchiger and Renner, claims that the Everett interpretation produces modal contradictions in Wigner's-friend scenarios with encapsulated measurements: a super-observer (possibly a quantum automaton) measures the memory register of an observer system after that system has measured a qubit spin. This is presented as showing the Everett interpretation to be inconsistent.

Significance. If substantiated by an explicit derivation, the result would be significant for quantum foundations by identifying an internal inconsistency in Everett relative to unrestricted super-observer measurements on observer memory. The manuscript correctly credits its connection to the authors' earlier information-theoretic alternative and to Frauchiger-Renner, but the significance hinges on whether the modal clash is shown to survive unmodified Everett branching and decoherence rather than being inherited from the cited works.

major comments (2)
  1. [Abstract and §1] Abstract and §1: the claim that 'the Everett interpretation leads to modal contradictions' in encapsulated Wigner's-friend setups is asserted without an explicit unitary evolution or branching description for the composite system (super-observer + observer memory + qubit). It is therefore unclear whether the single-valued outcome for the friend is an additional assumption or follows from the Everett formalism itself.
  2. [Following Frauchiger-Renner] Discussion following Frauchiger-Renner: the inconsistency conclusion requires that the super-observer's unrestricted measurement on the friend's memory produces a modality clash under unmodified Everett dynamics. No derivation is supplied showing that standard Everett branching at the friend's measurement (with multiple records) fails to dissolve the clash, as opposed to the argument reducing to the Frauchiger-Renner assumptions already present in the cited reference.
minor comments (1)
  1. Notation for the 'encapsulated' measurement could be clarified by distinguishing the friend's internal record from the super-observer's observable in a single diagram or equation.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the detailed report and for identifying points where the argument can be made more explicit. We agree that the manuscript would benefit from additional detail on the unitary evolution and branching structure, and we will revise accordingly to address both major comments.

read point-by-point responses

  1. Referee: [Abstract and §1] Abstract and §1: the claim that 'the Everett interpretation leads to modal contradictions' in encapsulated Wigner's-friend setups is asserted without an explicit unitary evolution or branching description for the composite system (super-observer + observer memory + qubit). It is therefore unclear whether the single-valued outcome for the friend is an additional assumption or follows from the Everett formalism itself.

    Authors: We accept that the current text does not spell out the unitary evolution step by step. The single-valued outcome for the friend is intended to follow from standard Everett branching after decoherence, in which each branch contains a definite record. To remove any ambiguity, the revised manuscript will include an explicit description of the composite-system unitary evolution, showing how the friend's measurement produces branching and how the subsequent super-observer measurement on the memory register generates the modal clash directly from the formalism. revision: yes

  2. Referee: [Following Frauchiger-Renner] Discussion following Frauchiger-Renner: the inconsistency conclusion requires that the super-observer's unrestricted measurement on the friend's memory produces a modality clash under unmodified Everett dynamics. No derivation is supplied showing that standard Everett branching at the friend's measurement (with multiple records) fails to dissolve the clash, as opposed to the argument reducing to the Frauchiger-Renner assumptions already present in the cited reference.

    Authors: The manuscript applies the Frauchiger-Renner reasoning to Everett rather than re-deriving the full argument from scratch. We agree that an explicit demonstration is needed to show why unmodified Everett branching does not dissolve the clash when the super-observer measures the memory register. The revised version will expand this section with a short derivation that isolates the modal contradiction under standard Everett dynamics, making clear that the result does not rest solely on the cited assumptions. revision: yes

Circularity Check

0 steps flagged

Minor self-citation to prior work; central inconsistency claim follows external Frauchiger-Renner argument

full rationale

The paper references its earlier collaboration with Pitowsky on an information-theoretic interpretation as context for preferring an alternative to Everett, but the load-bearing demonstration of modal contradictions in Wigner's-friend scenarios is explicitly presented as following from the external Frauchiger-Renner analysis. No self-definitional reductions, fitted inputs renamed as predictions, or load-bearing uniqueness theorems imported via self-citation appear in the derivation. The central claim does not reduce to the paper's own inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The paper is a conceptual argument in quantum foundations and relies on standard assumptions of quantum mechanics and modal logic without introducing new fitted parameters or entities.

axioms (1)
  • domain assumption Standard quantum formalism applies to observer and super-observer systems including memory records
    Invoked when modeling encapsulated measurements in Wigner's-friend scenarios.

pith-pipeline@v0.9.0 · 5633 in / 1058 out tokens · 39811 ms · 2026-05-24T21:39:21.866884+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

22 extracted references · 22 canonical work pages

  1. [1]

    Two dogmas About quantum mechanics

    Jeffrey Bub and Itamar Pitowsky (2010). Two dogmas About quantum mechanics. In S. Saunders, J. Barrett, A. Kent, and D. Wallace (eds.), Many W orlds? Everett, Quantum Theory, and Reality , pp. 431–456 (Oxford University Press, Oxford, 2010)

    work page 2010

  2. [2]

    Quantum th eory cannot consis- tently describe the use of itself

    Daniela Frauchiger and Renato Renner (2018). Quantum th eory cannot consis- tently describe the use of itself. Nature Communications 9, article number 3711

    work page 2018

  3. [3]

    On formalisms a nd interpretations

    V eronika Baumann and Stefan Wolf (2018). On formalisms a nd interpretations. Quantum 2, 99–111

    work page 2018

  4. [4]

    Remarks on the mind-body question

    Eugene Wigner (1961). Remarks on the mind-body question . In I.J. Good (ed.), The Scientist Speculates, (Heinemann, London, 1961)

    work page 1961

  5. [5]

    Gleason (1957)

    Andrew N. Gleason (1957). Measures on the Closed Subspac es of Hilbert Space. Journal of Mathematics and Mechanics 6, 885–893 (1957)

    work page 1957

  6. [6]

    Quantum Logics: Strict- and Pro bability-Logics

    John von Neumann (1937). Quantum Logics: Strict- and Pro bability-Logics. A 1937 unfinished manuscript published in A.H. Taub (ed.), Collected W orks of John von Neumann , V olume 4 (Pergamon Press, Oxford and New Y ork, 1961), pp. 195–197. 14

    work page 1937

  7. [7]

    Unsolved problems in mathemati cs

    John von Neumann (1954). Unsolved problems in mathemati cs. An address to the International Mathematical Congress, Amsterdam, Septemb er 2, 1954. In Mikl´ os R´ edei and Michael St¨ oltzner (eds.),John von Neumann and the F oundations of Quantum Physics, pp. 231–245 (Kluwer Academic Publishers, Dordrecht, 2001 )

    work page 1954

  8. [8]

    Drawing the line between kinemat ics and dynamics in special relativity

    Michel Janssen (2009). Drawing the line between kinemat ics and dynamics in special relativity. Studies in History and Philosophy of Modern Physics 40, 26– 52 (2009)

    work page 2009

  9. [9]

    Brown (2006)

    Harvey R. Brown (2006). Physical Relativity: Space-time Structure from a dy- namical perspective (Oxford: Clarendon Press, 2006)

    work page 2006

  10. [10]

    Bananaworld: Quantum Mechanics for Primates (Oxford University Press, Oxford, 2016)

    Jeffrey Bub (2016). Bananaworld: Quantum Mechanics for Primates (Oxford University Press, Oxford, 2016)

    work page 2016

  11. [11]

    Quantum mechanics as a theory o f probability

    Itamar Pitowsky (2007). Quantum mechanics as a theory o f probability. In William Demopoulos and Itamar Pitowsky, editors, Festschrift in honor of Jef- frey Bub. Springer, Western Ontario Series in Philosophy of Science , New Y ork, 2007

    work page 2007

  12. [12]

    George Boole’s ‘conditions of possible experience’ and the quantum puzzle

    Itamar Pitowsky (1994). George Boole’s ‘conditions of possible experience’ and the quantum puzzle. British Journal for the Philosophy of Science 45, 95–125 (1994). ‘These . . . may be termed the conditions of possible e xperience. When satisfied they indicate that the data may have, when not satisfied they indicate that the data cannot have, resulted from a...

    work page 1994

  13. [13]

    Macroscopic objects in quantu m mechanics: a combina- torial approach.Physical Review A 70, 022103–1–6 (2004)

    Itamar Pitowsky (2004). Macroscopic objects in quantu m mechanics: a combina- torial approach.Physical Review A 70, 022103–1–6 (2004)

    work page 2004

  14. [14]

    The causality problem in atomic phys ics

    Niels Bohr (1939). The causality problem in atomic phys ics. In New Theories in Physics (International Institute of Intellectual Cooperation, Wa rsaw,1939), pp. 11–30

    work page 1939

  15. [15]

    Discussions with Einstein on episte mological problems in modern physics

    Niels Bohr (1949). Discussions with Einstein on episte mological problems in modern physics. In P . A. Schilpp (ed.), Albert Einstein: Philosopher-Scientist , The Library of Living Philosophers, V olume 7 (Open Court, Evanston, 1949), pp. 201–241

    work page 1949

  16. [16]

    ‘Probability and physics,’ in C harles P

    Wolfgang Pauli (1954). ‘Probability and physics,’ in C harles P . Enz and Karl von Meyenn (eds.), W olfgang Pauli: Writings on Physics and Philosophy (Springer, Berlin, 1994), p. 46. The article was first published in Dialectica 8, 112-124 (1954)

    work page 1954

  17. [17]

    The philosophy of Niels Bohr

    Aage Petersen (1963). The philosophy of Niels Bohr. Bulletin of the Atomic Sci- entists 19, 8-14 (1963)

    work page 1963

  18. [18]

    Explaining the unobse rved: why quantum mechanics ain’t only about information

    Amit Hagar and Meir Hemmo (2006). Explaining the unobse rved: why quantum mechanics ain’t only about information. F oundations of Physics36,1295-1234. 15

    work page 2006

  19. [19]

    Quantum interacti ons with closed timelike curves and superluminal signaling

    Jeffrey Bub and Allen Stairs (2014). Quantum interacti ons with closed timelike curves and superluminal signaling. Physical Review A 89, 022311

    work page 2014

  20. [20]

    Notes on the discussion of ‘Quant um theory cannot con- sistently describe the use of itself.’ Unpublished

    Renato Renner (2019). Notes on the discussion of ‘Quant um theory cannot con- sistently describe the use of itself.’ Unpublished

    work page 2019

  21. [21]

    Quantum theory and the limits of objectivity

    Richard Healey (2018). Quantum theory and the limits of objectivity. F oundations of Physics 49, 1568–1589 (2018)

    work page 2018

  22. [22]

    Quantum mechanics for cosmologists

    John Bell (1987). Quantum mechanics for cosmologists. In J.S. Bell, Speakable and Unspeakable in Quantum Mechanics (Cambridge University Press, Cam- bridge, 1987). 16

    work page 1987