# Consciousness and Quantum Mechanics *Edited by Shan Gao. Oxford University Press, 2022 (Philosophy of Mind series). This is an edited volume, not a book by Gao: seventeen newly written chapters by twenty-two philosophers and physicists, including one Nobel laureate (Roger Penrose). Gao wrote the Introduction and one chapter (ch. 8). The book asks whether the two great puzzles, the measurement problem in quantum mechanics and the place of consciousness in nature, are connected, in either direction. Part I tests the old idea that consciousness collapses the wave function, now in precise, testable forms. Part II asks what role minds and experience must play in the various interpretations of quantum theory. Part III collects proposals that use quantum physics to explain consciousness, from Penrose and Hameroff's Orch OR to Bohm–Hiley "active information" and Smolin's relational "views". No consensus emerges, and the editor doesn't claim one. The volume is a map of live positions, several of which contradict one another.* > **What I actually read.** The book is in copyright and has no legal free full text, and I **did not read it cover to cover**. What I did read: the full **table of contents** with start pages (Google Books, Ingram via Better World Books, and Oxford Academic chapter pages, which agree); the OUP abstracts for the volume, the Introduction extract and chapters 5, 13, 14, 16 and 17; Steven French's long **review** in the *BJPS Review of Books* (2023), which covers every chapter and gives page references; and the **authors' own preprints** of five chapters: Chalmers & McQueen (arXiv 2105.02314, read in full), Okon & Sebastián (the OUP uncorrected proof the authors host at UNAM, opening pages), Kent (arXiv 1806.10396), Hardy (arXiv 1705.04620) and Silberstein & Stuckey (arXiv 1901.10825), the last three from their abstracts and introductions. Preprints can differ from the printed text. Where I give a page number from the printed book, it comes from French's review or OUP. Chapter page ranges are worked out from the start pages in the contents (verified directly from OUP for chs. 13, 14 and 16). Contributor affiliations are approximate, from their preprints and institutional pages, not from the book's List of Contributors. Related in this vault: the source note [[Video Summaries/Curt Jaimungal/Roger Penrose My Crazy Idea That Explains the Universe]]; Penrose's [[Book Summaries/Penrose, Roger/The Emperor's New Mind - Roger Penrose|The Emperor's New Mind]] (where Penrose's case that understanding is non-computational starts) and [[Book Summaries/Penrose, Roger/Fashion, Faith, and Fantasy in the New Physics of the Universe - Roger Penrose|Fashion, Faith, and Fantasy in the New Physics of the Universe]] (which first sketches the quantum-versus-classical "reality" distinction his ch. 13 develops); Schrödinger's [[Book Summaries/Schrödinger, Erwin/What Is Life - Erwin Schrödinger|What Is Life?]], whose Epilogue argues for a single mind; the editor hub [[Book Summaries/Gao, Shan/Gao, Shan|Gao, Shan]]; and the [[Book Summaries/Penrose, Roger/Penrose, Roger|Penrose, Roger]] hub, which links here for ch. 13. ## 1. Book facts | | | |---|---| | Title | *Consciousness and Quantum Mechanics*. Series: Philosophy of Mind (OUP) | | Editor | **Shan Gao**, Professor, Research Center for Philosophy of Science and Technology, Shanxi University (Taiyuan, China) | | Contributors | 22 authors of 17 chapters (listed in the outline below) | | Edition verified | **Oxford University Press, New York, 2022.** © Oxford University Press 2022. Hardcover ISBN **978-0-19-750166-5** (0197501664); online ISBN 9780197501696; DOI [10.1093/oso/9780197501665.001.0001](https://doi.org/10.1093/oso/9780197501665.001.0001). Published on Oxford Academic **18 July 2022**. Retailers date the US hardcover 7 October 2022. Front matter: Acknowledgments (vii), List of Contributors (ix), Information on Editor (xi). Introduction pp. 1–8, chapters pp. 11–514, Index p. 515. UK list price £64 (French's review) | | Structure | Introduction; Part I, Consciousness and Wave Function Collapse (chs. 1–4); Part II, Consciousness in Quantum Theories (chs. 5–12); Part III, Quantum Approaches to Consciousness (chs. 13–17) | | Penrose chapter | **Verified.** Ch. 13, "New Physics for the Orch-OR Consciousness Proposal", Roger Penrose, pp. 317–362 (OUP chapter page; DOI [10.1093/oso/9780197501665.003.0014](https://doi.org/10.1093/oso/9780197501665.003.0014)) | | Audiobook | **None found** (no Audible listing, 2026-11-10) | | Open Library | Work [OL27820845W](https://openlibrary.org/works/OL27820845W); edition [OL38015373M](https://openlibrary.org/books/OL38015373M) (no scan, no cover image) | **Where it came up.** - Video: [Roger Penrose: "My Crazy Idea That Explains the Universe"](https://www.youtube.com/watch?v=iO03t21xhdk), *Curt Jaimungal* (Theories of Everything), published 2025-11-03, 1:56:13. At [1:39:45](https://www.youtube.com/watch?v=iO03t21xhdk&t=5985s) Penrose brings up his article in Shan Gao's *Consciousness and Quantum Mechanics* (OUP) as the place where he set out "quantum reality" versus "classical reality". He says he regrets leaving out a clear diagram of the EPR (Alice and Bob) case, showing how the retrocausal bookkeeping avoids causal paradoxes because only quantum reality is involved. Earlier in the interview he explains why he thinks his version of gravitational collapse avoids the heating that underground experiments have ruled out for Diósi's version, and he refers forward to this chapter and *Fashion, Faith, and Fantasy* for the details. - Requested by Video Summaries on 2026-11-06. The queue note asked for the bibliographic details to be verified and the Penrose chapter to be checked (both done above), and said not to file the book as sole-author Gao. It is filed under the editor, with the hub noting "as editor". ## 2. Book resources **Reference and catalog pages.** Publisher: [Oxford Academic book page](https://academic.oup.com/book/44484) (abstracts for every chapter; full text by subscription). Google Books: [gJ6FEAAAQBAJ](https://books.google.com/books/about/Consciousness_and_Quantum_Mechanics.html?id=gJ6FEAAAQBAJ) (contents). Open Library: [OL27820845W](https://openlibrary.org/works/OL27820845W). Review: Steven French, ["Shan Gao, *Consciousness and Quantum Mechanics*"](https://www.thebsps.org/reviewofbooks/french-on-gao/), *BJPS Review of Books* (2023). **Free (legal).** - **The whole book: no.** It is in copyright (2022). **Project Gutenberg, Faded Page, Internet Archive lending: not available.** Open Library has a record but no scan to borrow. - **Author preprints of individual chapters: yes, for several.** These are the authors' own versions, posted with the book's permission or as preprints, so they are lawful to read. The printed text may differ. - Introduction: Gao's preprint, [PhilSci-Archive 20735](https://philsci-archive.pitt.edu/20735/). - Ch. 1, Chalmers & McQueen: [arXiv 2105.02314](https://arxiv.org/abs/2105.02314) (also talks at [consc.net/qm](https://consc.net/qm)). - Ch. 2, Okon & Sebastián: [authors' uncorrected proof, UNAM](https://filosoficas.unam.mx/~okon/english/okon-sebastian---2022---the.pdf). - Ch. 4, Kent: [arXiv 1806.10396](https://arxiv.org/abs/1806.10396). - Ch. 8, Gao: an earlier version, "Why mind matters in quantum mechanics" (2019), is listed on [PhilSci-Archive](https://philsci-archive.pitt.edu/view/subjects/consciousness.html). - Ch. 10, Silberstein & Stuckey: [arXiv 1901.10825](https://arxiv.org/abs/1901.10825). - Ch. 12, Hardy: [arXiv 1705.04620](https://arxiv.org/abs/1705.04620). - Ch. 15, Hiley & Pylkkänen: [University of Helsinki repository](https://researchportal.helsinki.fi/en/publications/can-quantum-mechanics-solve-the-hard-problem-of-consciousness/). - Ch. 17, Smolin: [PhilArchive SMOTPO-3](https://philarchive.org/archive/SMOTPO-3). - **Penrose's own follow-up (free):** ["On the Curiously Retro-causal Effects of Quantum..."](https://iopscience.iop.org/article/10.1088/1742-6596/3189/1/012003/pdf), *Journal of Physics: Conference Series* 3189 (open access). It restates the quantum-versus-classical reality distinction; Penrose writes that he "first spelt it out properly in Penrose [2022], p. 346", meaning ch. 13 of this book, and it adds the EPR diagram he says in the video he wished he had included. - **Libby/OverDrive: yes, ebook.** [OverDrive 9215510](https://www.overdrive.com/media/9215510/consciousness-and-quantum-mechanics). Whether your library licenses it is a local question. Academic libraries often have it on Oxford Academic. - **Hoopla:** I found no listing. - **Avoid:** Scribd and "instant download" PDF sites carrying the full book are pirated copies. Not linked. **Paid.** - **Amazon print.** [Hardcover, ISBN 0197501664](https://www.amazon.com/dp/0197501664). I found no paperback. - **Kindle.** Yes: [ASIN B0BCQYGK4W](https://www.amazon.com/dp/B0BCQYGK4W). - **Audible.** No audiobook found. - **Edition note.** Only one edition exists (2022). If you mainly want Penrose and Hameroff, ch. 13's ideas are covered more briefly, for free, in the IOP paper above. The library ebook is the cheapest route to the whole volume. ## 3. Editor and contributors **Shan Gao (editor).** Born 1 May 1971 in China. BSc in electronic engineering from Beihang University (1992) and MSc from the Chinese Academy of Sciences' Institute of Electronics (1995), then a career change to the foundations of physics. He took his PhD in history and philosophy of science at the **University of Sydney** (2009–12, degree conferred 2013) under Huw Price and Dean Rickles, with a thesis on interpreting quantum mechanics as the "random discontinuous motion" of particles. He was assistant and then associate professor at the CAS Institute for the History of Natural Sciences (2013–17), and since 2017 has been **Professor at Shanxi University's Research Center for Philosophy of Science and Technology**. He is the founder and managing editor of the *International Journal of Quantum Foundations*, and was a Visiting Fellow at Pittsburgh's Center for Philosophy of Science in 2024. His monograph is *The Meaning of the Wave Function: In Search of the Ontology of Quantum Mechanics* (CUP, 2017). His other edited volumes are *Protective Measurement and Quantum Reality* (CUP, 2015), *Quantum Nonlocality and Reality: 50 Years of Bell's Theorem* (co-edited with Mary Bell, CUP, 2016) and *Collapse of the Wave Function* (CUP, 2018). He has also written two popular books in Chinese, *Quantum: A Historical and Logical Journey* (2003) and *God Does Play Dice with the Universe* (2009). He has worked on consciousness and collapse since the 2000s, for example "A quantum theory of consciousness" (*Minds and Machines*, 2008) and a paper on the Diósi–Penrose collapse criterion (2010). The mentalistic form of the measurement problem defended in his ch. 8 is central to his recent work. (Sources: Shanxi University faculty page and CV; PhilPeople; IJQF "About".) **Key contributors (brief).** - **Roger Penrose** (b. 1931), Oxford mathematical physicist, Nobel Prize in Physics 2020 for the singularity theorem; with Hameroff, co-author of the Orch OR theory. See [[Book Summaries/Penrose, Roger/Penrose, Roger|his hub]]. - **Stuart Hameroff** (b. 1947), anesthesiologist, University of Arizona; director of its Center for Consciousness Studies and co-founder of the Tucson "Science of Consciousness" conferences. - **David J. Chalmers** (b. 1966), NYU philosopher who named the "hard problem" of consciousness; also the general editor of OUP's Philosophy of Mind series. **Kelvin J. McQueen** is a philosopher of physics at Chapman University. - **Adrian Kent**, Cambridge (DAMTP) and Perimeter Institute; quantum foundations and quantum cryptography. - **Lucien Hardy**, Perimeter Institute; known for Hardy's paradox (a version of Bell's theorem without inequalities) and for reconstructing quantum theory from axioms. - **Lee Smolin**, Perimeter Institute; loop quantum gravity, *The Trouble with Physics* (2006), *Time Reborn* (2013), *Einstein's Unfinished Revolution* (2019). - **Basil J. Hiley** (Birkbeck, London), David Bohm's long-time collaborator (*The Undivided Universe*, 1993), with **Paavo Pylkkänen** (Helsinki), philosopher of mind. - **Philip Goff** (Durham), the best-known current defender of panpsychism (*Galileo's Error*, 2019). - **Jenann Ismael** (Columbia at the time; now Johns Hopkins), **Peter J. Lewis** (Dartmouth), **William Seager** (Toronto Scarborough), **Michel Bitbol** (CNRS, Archives Husserl, Paris), **Elias Okon** and **Miguel Ángel Sebastián** (UNAM, Mexico), **J. Acacio de Barros** and **Carlos Montemayor** (San Francisco State), **Paul Skokowski** (Stanford), and **Michael Silberstein** and **W. M. Stuckey** (Elizabethtown College). ## 4. Author interviews and talks - **Penrose on this chapter:** the source video ([1:39:45](https://www.youtube.com/watch?v=iO03t21xhdk&t=5985s)). Penrose and Hameroff also present Orch OR together in many public talks and interviews. For the latest statement in print, see the IOP paper above. - **Chalmers & McQueen:** the earlier talks behind ch. 1 (from 2013 on) are posted at [consc.net/qm](https://consc.net/qm), as their preprint notes. - **Shan Gao:** I found no recorded interviews about the volume. His preprints on [PhilSci-Archive](https://philsci-archive.pitt.edu/view/subjects/consciousness.html), including the Introduction, are the best way to hear him in his own words. ## 5. Summary **Thesis (editor's framing).** The Introduction opens: "Consciousness and quantum mechanics are two mysteries in our times. It has been conjectured that a deep connection between them may exist. The connection is bidirectional." First, "an analysis of the conscious mind and psychophysical connection seems indispensable in understanding quantum mechanics and solving the notorious measurement problem". Gao quotes Harvey Brown: "The issue of psycho-physical parallelism is at the heart of the problem of measurement in quantum mechanics." Second, quantum mechanics, "the most fundamental theory of the physical world, will be relevant to understanding consciousness and even solving the mind-body problem when assuming a naturalist view, even though we are not quite there yet." A careful look at the possible connections is therefore "not only necessary but also even pressing". French's review sets the background: since Putnam's and Shimony's critiques in the early 1960s, consciousness had been close to taboo in mainstream philosophy of physics. This volume is a sign that it "has begun to tiptoe back into the limelight, as both explanans and explanandum." **Outline.** Chapter, author(s), pages (ranges inferred from the contents' start pages unless noted), then the argument. *Introduction, Shan Gao (pp. 1–8).* Sets out the two directions of the connection and previews the seventeen chapters in three parts. *Part I. Consciousness and Wave Function Collapse.* - **Ch. 1, "Consciousness and the Collapse of the Wave Function", David J. Chalmers and Kelvin J. McQueen (pp. 11–63).** Can a precise version of the von Neumann–Wigner idea, that consciousness collapses the wave function, survive? The simplest version, a superselection rule under which conscious states never superpose, falls to the **quantum Zeno effect**: the system would be frozen in one state, so "we would never wake up from a nap" (p. 27, per French). So they combine **integrated information theory** (IIT; consciousness measured by Φ and its "Q-shape") with **continuous spontaneous localization**-style gradual collapse. Collapse then acts on superpositions of different Q-shapes. This requires admitting brief superpositions of conscious states and tuning the collapse rate. Slow-collapse versions conflict with introspection, while faster versions might be ruled out by quantum computers. Their verdict: the model is "not as simple or powerful" as the leading interpretations, but "serves as an existence proof for a relatively precise consciousness-collapse model", is open to test, and "deserves attention". - **Ch. 2, "The Subjective-Objective Collapse Model: Virtues and Challenges", Elias Okon and Miguel Ángel Sebastián (pp. 64–82).** A physicalist-friendly model, first published in 2018, in which consciousness "causes" collapse because the collapse operator is tied to consciousness as a physical property, inside an objective (CSL-type) collapse scheme. Their distinction between **phenomenal and access consciousness** explains why we don't notice the transitions. They defend it against objections from theories of consciousness and from quantum foundations, but concede it inherits the usual problems of collapse models (a tuned parameter, the "tails" problem). Their closing line: "We would be satisfied if our model turns out to be no worse than standard collapse models." - **Ch. 3, "Quantum Mentality: Panpsychism and Panintentionalism", J. Acacio de Barros and Carlos Montemayor (pp. 83–98).** The mentality quantum theory seems to need, whether through consciousness-causes-collapse or contextuality (an observer choosing the measurement context), is **intentional, not phenomenal**. They therefore propose "panintentionalism" in place of panpsychism. - **Ch. 4, "Perception Constraints on Mass-Dependent Spontaneous Localization", Adrian Kent (pp. 99–114).** Bassi, Deckert and Ferialdi argued that mass-density collapse models with experimentally allowed parameters would collapse a few-photon superposition in the human eye within the ~100 ms perception time. Kent reanalyses this and finds they treated the processes as happening *in vacuo* rather than in cytoplasm. Correcting that raises the required collapse rate "most likely by at least an order of magnitude", which casts doubt on the claim. Whether such models are viable is left open. *Part II. Consciousness in Quantum Theories.* - **Ch. 5, "Quantum Mechanics and the Consciousness Constraint", Philip Goff (pp. 117–139).** Against **wave-function monism**, the view that fundamental reality is a field in high-dimensional configuration space. Goff's "consciousness constraint" says any adequate theory must make at least some phenomenal concepts correspond to reality. The trouble monism has in recovering ordinary objects (patterns of "penetration resistance") also stops it accounting for consciousness, whether you are a materialist or not. French replies that the wave function's symmetry properties (Pauli exclusion) may give the monist what she needs. - **Ch. 6, "Against 'Experience'", Peter J. Lewis (pp. 140–155).** He extends Bell's "Against 'Measurement'" to "experience", "observation" and "consciousness". There are good uses (for example, neurophysiological analyses of collapse), bad ones (treating experience as an unanalysed primitive inside an interpretation) and "ugly" ones. Hameroff and Penrose's hypothesis is his example of an ugly one, but it is separate from their interpretation of quantum mechanics. - **Ch. 7, "Why Physics Should Care about the Mind, and How to Think about it Without Worrying about the Mind-Body Problem", Jenann Ismael (pp. 156–176).** Because "the evidence for our theories comes from experience", physics must eventually bring the mind under its theories. The hard problem can be set aside, because consciousness enters physics only "by making a difference to the behavior of physical objects" (p. 167). - **Ch. 8, "Why Mind Matters in Quantum Mechanics", Shan Gao (pp. 177–183).** The measurement problem stated mentally, as three claims that can't all be true (p. 178): (A1) an observer's mental state supervenes on her wave function; (A2) the wave function always evolves linearly; (A3) a measurement yields a single mental state with a definite record. Unlike Maudlin's physical formulation, this one holds whichever interpretation you adopt, and it shows that the **psychophysical connection** is part of the problem and so part of any solution. - **Ch. 9, "The Nature of Belief in No-Collapse Everett Interpretations", Paul Skokowski (pp. 184–197).** In Everett's "bare theory", an observer asked "did you get a determinate result?" can answer yes even while superposed. Skokowski argues that the answer is produced by language systems, not by introspecting a belief, and that without collapse there is no single belief state with determinate content. The superposition of consciousness has to be faced. - **Ch. 10, "The Completeness of Quantum Mechanics and the Determinateness and Consistency of Intersubjective Experience: Wigner's Friend and Delayed Choice", Michael Silberstein and W. M. Stuckey (pp. 198–259; the longest chapter).** Against recent Wigner's-friend no-go theorems, they give a "realist psi-epistemic" principle-based account (in the style of special relativity) that keeps quantum mechanics complete, keeps locality and free will, and yields a single world in which all observers agree on definite outcomes. Coupled with **neutral monism** (physical entities as "contextually given manifestations" of a Jamesian "unqualified actuality", p. 248), it is meant to remove both the measurement problem and the hard problem. - **Ch. 11, "The Roles Ascribed to Consciousness in Quantum Physics: A Revelator of Dualist (or Quasi-Dualist) Prejudice", Michel Bitbol (pp. 260–281).** Both consciousness-causes-collapse and its critics share a dualist picture. He argues from Husserlian **phenomenology** and the first-person standpoint instead: consciousness is a precondition of there being anything at all, not a cause inside the world. He finds **QBism** the most consistent phenomenological reading and links Fuchs's "participatory realism" to Merleau-Ponty. - **Ch. 12, "Proposal to Use Humans to Switch Settings in a Bell Experiment", Lucien Hardy (pp. 282–314).** A Bell test over about 100 km with about 100 people at each end wearing EEG headsets whose brain signals switch the settings. If human-chosen settings yielded *agreement* with Bell's inequality (a violation of quantum theory), consciousness would be shown to play a special, perhaps dualist, role. Hardy rates the chance of that optimistically at 1–2% (p. 310), but argues that the experiment is just about feasible and worth doing for the technology alone. *Part III. Quantum Approaches to Consciousness.* - **Ch. 13, "New Physics for the Orch-OR Consciousness Proposal", Roger Penrose (pp. 317–362; verified on OUP).** OUP abstract: "The human ability to achieve conscious understanding is argued to be a non-computational process. For this to be in accordance with physical laws requires something beyond current physical theory, in supplying a physical basis for 'the collapse of the wave function', denoted OR [OUP's abstract misprints "demoted"]. This is argued to be an effect of gravitation on quantum mechanics. OR events are what allow a firm classical reality to arise from a quantum reality having a somewhat weaker ontological status. When appropriately orchestrated, these 'proto-conscious' OR events become genuine conscious processes." The chapter is long and wide-ranging. It covers his Gödel argument, non-periodic (Penrose) tilings and the gravitational OR proposal. Both gradual and instantaneous collapse are problematic, so he argues collapse acts **retroactively**: "the 'objective reality' of the situation is that the surviving member of the OR process was retroactively pre-determined by the 'choice' that would later be made by the OR occurrence!" (p. 342). At p. 346 he spells out the **quantum versus classical reality** distinction using "Einstein's dictum", the EPR criterion of reality. Of classical reality you can ask "What is your state?". Of quantum reality you can only ask "Is your state X?" and get a certain yes or no. The retroactivity, he argues, explains how conscious decisions can act within a small fraction of a second, against the common inference that such fast acts must be unconscious, and it explains Benjamin Libet's 1970s "backward referral" timing puzzles. Microtubules with suitable symmetries are proposed as the place where large-scale quantum states could be shielded. He admits that much of this is highly speculative and lacks detail (p. 354, per French). In the source video he says he wishes he had included an explicit EPR diagram here; he supplies one in the later IOP paper. - **Ch. 14, "Orch OR and the Quantum Biology of Consciousness", Stuart Hameroff (pp. 363–414; verified).** The biology side of Orch OR. Microtubules, polymer lattices of tubulin, (1) encode memory and process information, (2) orchestrate quantum vibrational superpositions (qubits) of **pi-electron resonance dipoles** in tubulin, (3) evolve to the OR threshold for "full, rich conscious experience", (4) most likely in dendrites and soma of **cortical layer 5 pyramidal neurons**, and (5) select microtubule states that regulate axonal firing. Penrose's retroactivity (6) "can resolve Libet's backward time referral, and rescue conscious free will". Against the "too warm, wet and noisy" objection, he points to a "quantum underground" of quantum-friendly protected structures and a "decoherence-free subspace" (p. 378). He insists the theory "is testable and falsifiable". French notes that the proposed mechanism has shifted over the years (earlier Bose–Einstein condensation, now dipole oscillations) and treats Orch OR as a Lakatosian research programme with high "buy-in" costs. - **Ch. 15, "Can Quantum Mechanics Solve the Hard Problem of Consciousness?", Basil J. Hiley and Paavo Pylkkänen (pp. 415–459).** Bohm's ontological interpretation: the quantum potential carries **"active information"** that organizes a particle's motion by its form, not its strength (as a radio signal steers a ship). From there they argue that meaning and matter are two sides of one process. Quantum particles have proto-mental qualities, a **panprotopsychism**, and phenomenal properties emerge in the right structures such as brains. Quantum holism even suggests a kind of cosmopsychism. They call for "non-mechanical, organic and holistic concepts such as active information to play a fundamental role" (p. 413). The proposal is offered as speculative. - **Ch. 16, "Strange Trails: Science to Metaphysics", William Seager (pp. 460–481; verified).** Quantum mechanics is highly **mathematically** intelligible but poorly **mundanely** intelligible, and interpretations try to supply metaphysical intelligibility. Seager surveys several and reads Bohm's as a radical, Leibniz-like metaphysics that "puts mentality, as the bearer of intrinsic information, as a fundamental feature of the world" (p. 478). - **Ch. 17, "On the Place of Qualia in a Relational Universe", Lee Smolin (pp. 482–514).** In Smolin's relational, realist "causal theory of views" (with Marina Cortês), the universe is "constructed from nothing but a collection of views of events" (p. 483). Each view is the information an event receives from its causal past. Only **novel** views, those with no copy in their causal past, are the physical correlates of conscious experience. The result is a "restricted", physically selected panpsychism that explains why qualia always come bundled. He tentatively locates the relevant quantum effects in neuronal membrane phospholipid bilayers. *Index (p. 515).* **Key ideas.** - **The measurement problem may be partly a mind problem.** Gao's ch. 8 restates it with mental states and argues the psychophysical link can't be left out of any solution. - **Consciousness-causes-collapse is back, but in testable form.** Chalmers & McQueen and Okon & Sebastián build precise models. The price is the quantum Zeno problem, tuned collapse rates and possibly superposed experiences. - **Perception sets limits on collapse theories.** Kent and Hardy turn the question into physics: how fast must collapse happen in an eye, and what if human choices altered Bell statistics? - **Some interpretations argue minds away; others make them basic.** Lewis wants "experience" out of the foundations. Ismael, Bitbol, Silberstein & Stuckey give experience a constitutive or neutral-monist role. - **Quantum theories of consciousness divide.** One family is Penrose–Hameroff's gravitational OR in microtubules, with retroactive collapse and non-computability. The other gives quantum physics a mind-like side: Bohm–Hiley active information, Smolin's novel views, Seager's Leibnizian intelligibility. - **No consensus.** The interpretations of quantum theory and the theories of consciousness can be combined in so many ways that French suspects a radically different approach may be needed. **Reception, in brief.** Steven French (Leeds), in the *BJPS Review of Books* (2023), called it "this rather inhomogeneous but suggestive collection" that "does at least bring the issues involved back onto centre stage". He praised Gao's introduction and ch. 8 as a good entry point, and noted "a certain degree of arbitrariness" in which chapters went in which part. He found many proposals "hand-wavey", Smolin's especially, and found himself sympathetic to Eddington's sign for physics departments, "Work in Progress: Keep out". OUP lists it as the first volume to survey these conjectures comprehensively. Its chapters are widely cited separately: Chalmers & McQueen in particular has become the standard modern statement of consciousness-collapse. ## 6. Fact-check Overall verdict: **mixed**. The bibliographic and structural facts all check out. The chapters are mostly arguments and proposals, not empirical claims. The empirical claims they do make are either untested (Orch OR, consciousness-collapse) or under real pressure from experiments. | Claim | Verdict | Evidence | |---|---|---| | Edited by Shan Gao, OUP 2022, 17 chapters in 3 parts; ISBN 9780197501665 | Supported | Oxford Academic (online 18 July 2022), Google Books, Ingram contents, copyright page | | Penrose contributes a chapter (Video Summaries flag) | Supported | Ch. 13, pp. 317–362, DOI 10.1093/oso/9780197501665.003.0014 | | Penrose (video 1:39:45): the chapter sets out "quantum vs classical reality" but lacks an EPR diagram | Supported | His later IOP paper says he "first spelt it out properly in Penrose [2022], p. 346" and adds the EPR figure | | Simple consciousness-collapse (superselection) fails because of the quantum Zeno effect (ch. 1) | Supported (within the model) | Chalmers & McQueen's own analysis, preprint §3; a standard result for continuously monitored systems | | Consciousness-collapse can in principle be tested with quantum computers (ch. 1) | Open | Proposed, not done; would require putting systems with high integrated information into superposition | | Collapse models imply that collapse in the eye happens within ~100 ms (Bassi et al.) | Disputed | Kent (ch. 4) argues that the cytoplasm correction raises the needed rate by at least an order of magnitude | | Human-chosen Bell settings might violate quantum theory (ch. 12) | Untested in Hardy's form; no deviation so far | The BIG Bell Test (*Nature* 557, 212, 2018) used about 100,000 people's keyboard choices and found the usual quantum violations. That test was not Hardy's spacelike-separated EEG design | | Gravitational OR (Diósi–Penrose) collapses superpositions | Open; partly constrained | Gran Sasso underground radiation test (Donadi et al., *Nature Physics* 17, 74, 2021) ruled out the simplest parameter-free Diósi–Penrose model. Penrose argues his version avoids the heating (source video), which is not experimentally settled | | Microtubules can sustain functional quantum coherence in warm brains (ch. 14) | Disputed | Tegmark (*Phys. Rev. E* 61, 4194, 2000) estimated decoherence in ~10⁻¹³–10⁻²⁰ s. Hameroff and Hagan replied with longer estimates. Some suggestive later results (for example microtubule-stabilizing drugs delaying anesthesia in rats, *eNeuro* 2024) exist but are not a demonstration | | Retroactive OR explains Libet's "backward referral" (chs. 13–14) | Speculative | Libet's 1979 subjective-timing results are themselves contested in interpretation. The retroactive account is Penrose's proposal, not an established result | | Conscious understanding is non-computational (Gödel argument, ch. 13) | Disputed | Long-standing criticism by Feferman, Putnam, Chalmers and others since *The Emperor's New Mind*. See that dossier | | Hiley & Pylkkänen's "active information" is Bohm's interpretation, not a new empirical theory | Supported | Bohm & Hiley, *The Undivided Universe* (1993). Its predictions match standard quantum mechanics | | Contributor affiliations given here | Approximate | From preprints and institutional pages, not the book's List of Contributors | ## 7. Citations and references **What the book draws on (from the chapters I saw).** von Neumann (1932) and Wigner (1961/62) on observation and collapse; London & Bauer (1939); Putnam (1961) and Shimony (1963); Bell, "Against 'Measurement'" (1990); Everett (1957); GRW and Pearle's continuous spontaneous localization; Diósi and Penrose on gravitational collapse; Tononi's integrated information theory; Bassi, Deckert & Ferialdi on collapse in the eye; Bohm (1952) and Bohm & Hiley (1993); QBism (Fuchs, Schack, Mermin); Husserl and Merleau-Ponty; Libet's timing experiments; Gödel's theorems; Maudlin, "Three Measurement Problems" (1995); Ney and Albert on wave-function realism; Wallace on emergence in Everett; Frauchiger–Renner and Brukner Wigner's-friend theorems; Cortês & Smolin's causal theory of views. **Related works.** Shan Gao, *The Meaning of the Wave Function* (CUP, 2017) and *Collapse of the Wave Function* (ed., CUP, 2018). Penrose, [[Book Summaries/Penrose, Roger/The Emperor's New Mind - Roger Penrose|The Emperor's New Mind]] (1989), *Shadows of the Mind* (1994), [[Book Summaries/Penrose, Roger/Fashion, Faith, and Fantasy in the New Physics of the Universe - Roger Penrose|Fashion, Faith, and Fantasy]] (2016). Hameroff & Penrose, "Consciousness in the universe: A review of the 'Orch OR' theory", *Physics of Life Reviews* 11 (2014) 39–78. Chalmers, *The Conscious Mind* (1996). Henry Stapp, *Mindful Universe* (2007). Bohm & Hiley, *The Undivided Universe* (1993). Philip Goff, *Galileo's Error* (2019). Smolin, *Einstein's Unfinished Revolution* (2019). Schrödinger, [[Book Summaries/Schrödinger, Erwin/What Is Life - Erwin Schrödinger|What Is Life?]] (Epilogue) and *Mind and Matter*. **Links this note used:** - Catalogs and contents: [Oxford Academic, book 44484](https://academic.oup.com/book/44484); [OUP ch. 13 abstract](https://academic.oup.com/book/44484/chapter-abstract/376470269); [DOI ch. 14](https://doi.org/10.1093/oso/9780197501665.003.0015); [DOI ch. 16](https://doi.org/10.1093/oso/9780197501665.003.0017); [Google Books](https://books.google.com/books/about/Consciousness_and_Quantum_Mechanics.html?id=gJ6FEAAAQBAJ); [Better World Books (Ingram contents)](https://www.betterworldbooks.com/product/detail/consciousness-and-quantum-mechanics-9780197501665/new); [Open Library OL27820845W](https://openlibrary.org/works/OL27820845W). - Preprints: [PhilSci 20735 (Introduction)](https://philsci-archive.pitt.edu/20735/); [arXiv 2105.02314](https://arxiv.org/abs/2105.02314); [Okon & Sebastián proof](https://filosoficas.unam.mx/~okon/english/okon-sebastian---2022---the.pdf); [arXiv 1806.10396](https://arxiv.org/abs/1806.10396); [arXiv 1901.10825](https://arxiv.org/abs/1901.10825); [arXiv 1705.04620](https://arxiv.org/abs/1705.04620); [Helsinki portal, Hiley & Pylkkänen](https://researchportal.helsinki.fi/en/publications/can-quantum-mechanics-solve-the-hard-problem-of-consciousness/); [PhilArchive SMOTPO-3](https://philarchive.org/archive/SMOTPO-3); [Penrose, IOP JPCS 3189 012003](https://iopscience.iop.org/article/10.1088/1742-6596/3189/1/012003/pdf). - Editor: [Shanxi University faculty page](https://zxxy.sxu.edu.cn/szdw/kxjszx/40b3b72501ae42b7aa33fdd124b199bc.htm); [PhilPeople](https://philpeople.org/profiles/shan-gao); [IJQF, About Shan Gao](https://ijqf.org/shangao); [Pitt Center for Philosophy of Science](https://www.centerphilsci.pitt.edu/fellows/gao-shan/). - Shops and libraries: [Amazon hardcover](https://www.amazon.com/dp/0197501664); [Kindle B0BCQYGK4W](https://www.amazon.com/dp/B0BCQYGK4W); [OverDrive 9215510](https://www.overdrive.com/media/9215510/consciousness-and-quantum-mechanics). - Review: [French, *BJPS Review of Books*](https://www.thebsps.org/reviewofbooks/french-on-gao/). - Source video: [Roger Penrose: "My Crazy Idea That Explains the Universe"](https://www.youtube.com/watch?v=iO03t21xhdk); [[Video Summaries/Curt Jaimungal/Roger Penrose My Crazy Idea That Explains the Universe]].