Head to head
Crick and Koch’s NCC vs Dennett’s Illusionism
Crick and Koch’s Neural Correlates of Consciousness (NCC) and Dennett’s Illusionism, compared field by field from their entries in the Atlas.
At a glance
- Both belong to the Materialism family in Kuhn's Landscape of Consciousness.
- Both treat consciousness as emergent.
- They give the same kind of answer on life after death and meaning and purpose.
- On AI consciousness, Crick and Koch’s NCC says “Yes” and Dennett’s Illusionism says “Possible”.
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The claim
In brief
Crick and Koch’s NCCThis theory proposes a scientific agenda to identify the Neural Correlate of Consciousness (NCC), defined as the minimum activities in the brain that are jointly sufficient and necessary for any specific conscious perception or subjective experience. It asserts that consciousness is entirely physical and can be fully reduced to these specific brain activities.
Dennett’s IllusionismDaniel Dennett argues that qualia, conceived as intrinsic, ineffable, private, and immediately known properties of experience, do not exist; they are philosophers’ inventions. Experience is real, but it is not what it seems from the inside: the brain’s unconscious processes produce a benign ‘user illusion’, and there is nothing to consciousness beyond the functions and dispositions involved.
What consciousness is
Crick and Koch’s NCCConsciousness (phenomenal consciousness/qualia) is identified as the Neural Correlate of Consciousness (NCC), the precise minimum pattern of neural activity in the brain necessary and sufficient for subjective experience.
Dennett’s IllusionismConsciousness is the functional activity of the brain, which presents itself to us as a user illusion. ‘There are no qualia.’
Big questions
Can AI be conscious?Differ
Crick and Koch’s NCCYesIf consciousness is entirely reducible to physical organizational patterns (NCC), then non-biological systems capable of replicating those precise patterns should also become conscious, barring technological constraints.
Dennett’s IllusionismPossibleSince consciousness is nothing beyond functions and dispositions, a machine with the right functional organization could have it; Dennett does not take this up here.
Does consciousness survive death?Both agree
Crick and Koch’s NCCNoAs a Materialist theory, consciousness is wholly dependent on the physical brain; cessation of brain function entails the end of consciousness.
Dennett’s IllusionismNoSince consciousness is a product of the brain’s processes, it ends when they end.
Crick and Koch’s NCCYesIf the NCC states can be perfectly measured and replicated in a digital or artificial medium (mind uploading), the resulting system would be functionally and phenomenally identical, achieving virtual immortality in principle.
Dennett’s IllusionismNo position
Does it give life meaning?Both agree
Crick and Koch’s NCCHumanistic onlyConsistent with Materialism, consciousness is a biological product of evolution and physics, conferring no ultimate cosmic meaning or teleology beyond that which humans create for themselves.
Dennett’s IllusionismHumanistic onlyDennett’s materialism, and his place among the New Atheists, leave no room for cosmic purpose.
Nature of mind
Ontology
Crick and Koch’s NCCReductive Physicalism/Materialism. The NCC approach is considered macroscopic materialism.
Dennett’s IllusionismPhysicalism (illusionist)
Mind and body
Crick and Koch’s NCCIdentity Theory. Mental states are wholly identical to and fully explained by the physical NCC states.
Dennett’s IllusionismConsciousness is wholly a product of the brain’s unconscious processes. Dennett rejects any inner, non-physical domain of felt properties.
Fundamental or emergent
Crick and Koch’s NCCEmergent
Dennett’s IllusionismEmergent
Qualia
Crick and Koch’s NCCQualia (the qualitative feel of experience) are identified with the minimum neural activities (NCC) that are jointly sufficient for specific conscious perception, although the mechanism for this identity remains the central 'hard problem' challenge.
Dennett’s IllusionismThere are no qualia in the traditional sense. Dennett calls the supposed intrinsic, ineffable, private properties ‘nothing but philosophers’ inventions’.
How it works
Mechanism
Crick and Koch’s NCCThe search for and definition of the Neural Correlate of Consciousness (NCC): the specific minimum neural activities necessary and sufficient for subjective experience.
Dennett’s IllusionismThe user illusion. As a computer’s desktop icons stand in for complex underlying processes, the brain presents itself to us in a simplified form we mistake for an inner world of qualities.
Where it is
Crick and Koch’s NCCLocalized in specific brain areas. Early candidates included the claustrum (as a 'conductor' coordinating percepts); later candidates focused on the posterior cerebral cortex (temporo-parietal-occipital hot zone).
Dennett’s IllusionismIn the brain’s unconscious processes, with no inner theater.
What it does
Crick and Koch’s NCCConsciousness is directly caused by, and is identical to, the NCC activity. NCC mechanisms (spikes, flows, circuits) are seen as constitutive of phenomenal consciousness.
Dennett’s IllusionismThe user illusion is benign: it lets us manage ourselves without access to the brain’s underlying complexity.
Evidence and criticism
Testability
Crick and Koch’s NCCEmpirically testable. The search for the NCC is defined as a scientific program seeking testable biological bases for consciousness.
Dennett’s IllusionismConceptually testable
Tests so far
Crick and Koch’s NCCIdentifying specific clusters of neurons or brain regions (like the claustrum or posterior cortex) that are active during conscious experience.,Measuring electrophysiological activity (e.g., action potentials and neural circuits).
Dennett’s IllusionismNot stated
Criticisms
Crick and Koch’s NCCThe primary tension is the 'explanatory gap': identifying a correlation (NCC) does not explain the identity statement of how physical activity (spikes/chemicals) literally generates phenomenal feel (qualia). The failure to identify a 'clear' NCC after decades of research is a practical limitation.
Dennett’s IllusionismDennett is often read as denying that experience exists, and critics reply that an illusion of experience would itself be an experience. Dennett resisted the eliminativist label, though many philosophers apply it to his rejection of qualia.
Sources
Key sources
Crick and Koch’s NCC
- Towards a neurobiological theory of consciousness, F. Crick and C. Koch (1990)
- What is the function of the claustrum?, F. Crick and C. Koch (2005)
- The Quest for Consciousness: a Neurobiological Approach, C. Koch (2004)
Dennett’s Illusionism
- Consciousness Explained, Daniel Dennett
- I've Been Thinking, Daniel Dennett (2023)
- Dennett’s Illusionism (Landscape of Consciousness), Daniel Dennett (1992)