Head to head
Dennett’s Illusionism vs Sam Harris
Dennett’s Illusionism and S. Harris’s Mystery of Consciousness, compared field by field from their entries in the Atlas.
At a glance
- Dennett’s Illusionism belongs to the Materialism family in Kuhn's Landscape of Consciousness, Sam Harris to Challenge.
- They give the same kind of answer on life after death and meaning and purpose.
- On AI consciousness, Dennett’s Illusionism says “Possible” and Sam Harris says “No”.
Add more theories to this comparisonCompare other theories
The claim
In brief
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.
Sam HarrisThis perspective, offered as a challenge rather than a prescriptive theory, frames consciousness as an unbridgeable mystery that cannot be solved by purely physical means. Harris argues that physical descriptions are 'mute' regarding subjective experience; the only thing attesting to sentience is consciousness itself, creating a fundamental explanatory gap. He remains pessimistic that science can dispel this mystery.
What consciousness is
Dennett’s IllusionismConsciousness is the functional activity of the brain, which presents itself to us as a user illusion. ‘There are no qualia.’
Sam HarrisConsciousness is identified as subjectivity or sentience, which is fundamentally mysterious and unexplainable by purely physical processes.
Big questions
Can AI be conscious?Differ
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.
Sam HarrisNoIf consciousness is irreducible subjectivity missing from physical descriptions, then advanced computation (AI, which is purely physical complexity) will fail to generate genuine sentience.
Does consciousness survive death?Both agree
Dennett’s IllusionismNoSince consciousness is a product of the brain’s processes, it ends when they end.
Sam HarrisNoAs a naturalist, Harris implicitly aligns with the view that consciousness is tied to the physical organism, meaning its termination results in permanent non-existence, despite the mystery of its nature while alive.
Dennett’s IllusionismNo position
Sam HarrisNoIf consciousness cannot be explained by purely physical processes, then duplication or uploading of the physical substrate will fail to capture or recreate the essential subjective self.
Does it give life meaning?Both agree
Dennett’s IllusionismHumanistic onlyDennett’s materialism, and his place among the New Atheists, leave no room for cosmic purpose.
Sam HarrisHumanistic onlyThe mystery does not imply cosmic purpose, but Harris advocates finding personal truths through introspection, aligning with self-discovered (naturalized) spirituality and meaning.
Nature of mind
Ontology
Dennett’s IllusionismPhysicalism (illusionist)
Sam HarrisSkeptical/Mysterianism (Justified: The view asserts the philosophical intractability and unbridgeable nature of the mind-body problem, aligning with core tenets of mysterianism, though without adopting a specific alternative ontology.)
Mind and body
Dennett’s IllusionismConsciousness is wholly a product of the brain’s unconscious processes. Dennett rejects any inner, non-physical domain of felt properties.
Sam HarrisUnbridgeable Gap / Non-reductive Correlation (Justified: Harris asserts that while physical processes correlate with consciousness, no analysis of these processes can logically yield a picture of consciousness, leaving an unbridgeable gap.)
Fundamental or emergent
Dennett’s IllusionismEmergent
Sam HarrisMystery (Justified: Harris declines to fully endorse emergence, stating that while consciousness may be the lawful product of unconscious processing, he does not find that sentence meaningful in explaining sentience.)
Qualia
Dennett’s IllusionismThere are no qualia in the traditional sense. Dennett calls the supposed intrinsic, ineffable, private properties ‘nothing but philosophers’ inventions’.
Sam HarrisQualia (what it is 'like something' to be) are the phenomenon that physical events are 'mute' about, thus creating the unbridgeable mystery.
How it works
Mechanism
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.
Sam HarrisNone (Justified: The core premise is the failure of all current and foreseeable physical/mechanistic principles to explain subjectivity.)
Where it is
Dennett’s IllusionismIn the brain’s unconscious processes, with no inner theater.
Sam HarrisUnknown/Mysterious (Justified: While consciousness correlates with the brain, the theory explicitly rejects confining the explanation of consciousness to physical location or distribution because the physical world yields no evidence of consciousness.)
What it does
Dennett’s IllusionismThe user illusion is benign: it lets us manage ourselves without access to the brain’s underlying complexity.
Sam HarrisUnknown/Irreducible (Justified: Causal power is not explained by unconscious complexity. The presence of sentience is an ultimate mystery rather than a functional adaptation that can be described reductively.)
Evidence and criticism
Testability
Dennett’s IllusionismConceptually testable
Sam HarrisConceptually Untestable (Justified: If the gap is unbridgeable, as Harris claims, the mystery cannot be dispelled by empirical science as currently practiced.)
Tests so far
Dennett’s IllusionismNot stated
Sam HarrisNone (Justified: The framework is a diagnosis of science's failure to address the hard problem and does not propose empirical tests for the mystery itself.)
Criticisms
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.
Sam HarrisIt functions primarily as a critique against reductionism and scientific optimism regarding consciousness, classifying the issue as an ultimate mystery, which reductionists reject as pessimism (mysterianism).
Sources
Key sources
Dennett’s Illusionism
- Consciousness Explained, Daniel Dennett
- I've Been Thinking, Daniel Dennett (2023)
- Dennett’s Illusionism (Landscape of Consciousness), Daniel Dennett (1992)
Sam Harris
- The mystery of consciousness (Part I & II), Sam Harris (2011)
- Explorations in Consciousness: Death Psychedelics and Mystical Experience (2023)