Head to head
Eliminative Materialism vs Orch OR
Churchland’s Eliminative Materialism and Penrose-Hameroff’s Orchestrated Objective Reduction, compared field by field from their entries in the Atlas.
At a glance
- Eliminative Materialism belongs to the Materialism family in Kuhn's Landscape of Consciousness, Orch OR to Quantum & Dimensions.
- On life after death, Eliminative Materialism says “No” and Orch OR says “Possible”.
- On meaning and purpose, Eliminative Materialism says “Humanistic only” and Orch OR says “Cosmic/Ultimate”.
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Quantum & Dimensions
Penrose-Hameroff’s Orchestrated Objective Reduction
Roger Penrose, Stuart Hameroff
The claim
In brief
Eliminative MaterialismPaul and Patricia Churchland hold that common-sense psychology, our everyday talk of beliefs, desires, and experiences, is a radically false theory that a completed neuroscience will displace rather than smoothly reduce. Consciousness as we ordinarily conceive it is a brain-generated picture shaped by evolution, and our self-understanding, introspection included, will be rebuilt in neuroscientific terms.
Orch ORThis theory posits that consciousness arises from non-computational, gravitation-mediated objective reduction (OR) of quantum superpositions occurring within the protein structures (microtubules) inside brain neurons. This process, termed Orchestrated Objective Reduction (Orch OR), bridges the gap between quantum mechanics and classical reality to produce phenomenal experience.
What consciousness is
Eliminative MaterialismWhat we call consciousness, as folk psychology describes it, does not exist in that form. The real phenomena are neural processes, which only a mature neuroscience will describe correctly.
Orch ORConsciousness is identified as a non-computational physical process—the specific orchestration of gravitation-mediated objective reduction of quantum states linked to the fine-scale structure of spacetime geometry. Proto-conscious moments are fundamental and ubiquitous in the universe.
Big questions
Eliminative MaterialismNo position
Orch ORNoConsciousness is fundamentally non-computational and relies on specific biological quantum processes (Orch OR in microtubules); digital simulation cannot replicate true sentience.
Eliminative MaterialismNoSince the mind is the brain, nothing mental survives the brain’s death.
Orch ORPossibleAs a non-local quantum process in spacetime geometry, consciousness provides a potentially plausible mechanism for phenomena like near-death experiences, the afterlife, and reincarnation.
Eliminative MaterialismNo position
Orch ORConditionalMind uploading requires recreating consciousness in an artificial medium (e.g., carbon nanotubes) that possesses the necessary quantum physical properties to sustain and orchestrate objective reduction events.
Eliminative MaterialismHumanistic onlyPatricia Churchland urges us to see ourselves as organisms in nature, understood by scientific methods, with no cosmic purpose.
Orch ORCosmic/UltimateProto-conscious moments are fundamental and ubiquitous, linking consciousness to the fine-scale structure of reality, suggesting inherent cosmic relevance and possibly enabling evolution itself.
Nature of mind
Ontology
Eliminative MaterialismPhysicalism (eliminative)
Orch ORQuantum Theory (Non-computational Physicalism / Proto-panpsychism)
Mind and body
Eliminative MaterialismThe mind is the brain. Patricia Churchland calls her program a ‘unified theory of the mind-brain’ and treats claims that mind goes beyond brain as the residue of folk myths.
Orch ORConsciousness is non-computational physics. The brain's microtubules act as a mechanism to orchestrate proto-conscious quantum activity into coherent, rich conscious experiences, requiring a physics beyond current understanding.
Fundamental or emergent
Eliminative MaterialismNeither
Orch OREmergent/Primitive (Hybrid)
Qualia
Eliminative MaterialismQualia as folk psychology and philosophers conceive them are expected to give way to neuroscientific description; the view treats consciousness as a kind of illusion generated by the brain.
Orch ORRich conscious experience (qualia) arises when orchestrated objective reduction occurs in neuronal microtubules, connecting the quantum information processing to the fundamental structure of spacetime geometry.
How it works
Mechanism
Eliminative MaterialismTheory displacement. Folk psychology will be replaced the way outdated scientific theories were, its principles and ontology discarded rather than mapped onto brain states.
Orch OROrchestrated Objective Reduction (Orch OR), where non-computational, instantaneous quantum state collapse is leveraged by coherent quantum activity sustained within microtubule lattices.
Where it is
Eliminative MaterialismIn the brain.
Orch ORLocalized within neuronal microtubules, particularly in the brain, but fundamentally drawing upon ubiquitous proto-conscious properties throughout the universe.
What it does
Eliminative MaterialismBehavior is caused by neural processes; neuroscience is expected to explain it better than folk psychology does.
Orch ORConsciousness provides real-time conscious causal action through non-computable objective reduction events, potentially linked to the fundamental mechanisms of free will and choice.
Evidence and criticism
Testability
Eliminative MaterialismConceptually testable
Orch ORTheoretically testable; versions involving collapse dynamics can, in principle, be tested with quantum computers, though current tests are rudimentary.
Tests so far
Eliminative MaterialismThe view stakes its claim on the future course of neuroscience; whether folk categories survive in mature brain science is the long-run test.
Orch ORStudies showing that general anesthetics, psychedelics, and antidepressants interact with microtubules.,Experiments aimed at testing quantum coherence maintenance in biological systems (e.g., tubulin studies).,Testing theoretical versions by combining IIT and collapse dynamics.
Criticisms
Eliminative MaterialismCritics say denying subjective experience defies both intuition and direct evidence; Galen Strawson calls the denial of experience ‘the strangest thing that has ever happened in the whole history of human thought’. There is also tension between Patricia Churchland’s talk of reduction to neurobiology and the eliminativist claim that folk psychology will be displaced rather than reduced.
Orch ORThe main tension is the challenge of maintaining quantum coherence for biological timescales in the hot, wet environment of the brain (environmental decoherence). The theory also requires non-existent physics (quantum gravity).
Sources
Key sources
Eliminative Materialism
- Neurophilosophy, Patricia Churchland (1986)
- Churchland’s Eliminative Materialism (Landscape of Consciousness), Patricia Churchland
Orch OR
- Shadows of the Mind: A Search for the Missing Science of Consciousness, Roger Penrose (1996)
- Conscious., Microtub. ‘Orch OR’, Stuart Hameroff (2014)
- Consciousness & new physics, Roger Penrose (2023)