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Dennett’s Illusionism vs Searle’s Biological Naturalism

Dennett’s Illusionism and Searle’s Biological Naturalism, compared field by field from their entries in the Atlas.

At a glance

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Materialism Dennett’s Illusionism Daniel Dennett
Materialism Searle’s Biological Naturalism John Searle

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.
Searle’s Biological NaturalismBiological Naturalism posits that consciousness is a real, irreducible, subjective biological feature of the brain, entirely caused by lower-level neurobiological processes and realized as higher-level system features. This approach seeks to solve the mind-body problem by accepting the scientific worldview while acknowledging the first-person ontology of conscious experience.
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.’
Searle’s Biological NaturalismConscious states are identified as real parts of the real world that are higher-level, system features of the brain, defined as states of awareness, sentience, or feeling that persist during wakefulness.

Big questions

Can AI be conscious?Both agree
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.
Searle’s Biological NaturalismConditionalSearle rejects consciousness via simulation (Chinese Room Argument) but argues that if the causally sufficient biological mechanism is known, an artificial machine that implements that same mechanism could be conscious, as consciousness does not strictly require biological neurons, only sufficient causal power.
Does consciousness survive death?Both agree
Dennett’s IllusionismNoSince consciousness is a product of the brain’s processes, it ends when they end.
Searle’s Biological NaturalismNoConsciousness is entirely physical and solely the product of biological brains; therefore, death of the brain and body means irrevocable, permanent non-existence.
Could a mind be uploaded?
Dennett’s IllusionismNo position
Searle’s Biological NaturalismYesIf consciousness is entirely explainable by physical/biological states, then duplicating those states (and their causal relations) in a non-biological medium would, in principle, allow for the uploading and continuation of the first-person mental 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.
Searle’s Biological NaturalismHumanistic onlyAs a materialist theory, Biological Naturalism struggles to rationalize ultimate cosmic meaning or purpose, though humanistic meaning created by ourselves remains possible.

Nature of mind

Ontology
Dennett’s IllusionismPhysicalism (illusionist)
Searle’s Biological NaturalismPhysicalism (Biological Naturalism). It holds that consciousness is part of nature as a subjective, qualitative biological property, rejecting attempts to 'naturalize' it by denying its subjective 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.
Searle’s Biological NaturalismConscious states are causally reduced to lower-level brain processes (causal reducibility), but are ontologically irreducible to these processes because consciousness has a subjective (first-person) ontology while its basis has an objective (third-person) ontology.
Fundamental or emergent
Dennett’s IllusionismEmergent
Searle’s Biological NaturalismEmergent
Qualia
Dennett’s IllusionismThere are no qualia in the traditional sense. Dennett calls the supposed intrinsic, ineffable, private properties ‘nothing but philosophers’ inventions’.
Searle’s Biological NaturalismConscious states are inherently qualitative, in the sense that there is a distinct qualitative feel to being in any particular conscious state, and this qualitative feel is a real and irreducible part of the world.

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.
Searle’s Biological NaturalismThe principle is that all conscious states are reliably and universally caused by lower-level brain processes and realized as system features, functioning as a real biological machine.
Where it is
Dennett’s IllusionismIn the brain’s unconscious processes, with no inner theater.
Searle’s Biological NaturalismLocalized in the biological brain, specifically realized in the brain as higher-level or system features.
What it does
Dennett’s IllusionismThe user illusion is benign: it lets us manage ourselves without access to the brain’s underlying complexity.
Searle’s Biological NaturalismConscious states function causally (causal efficacy) as real parts of the real world, providing a basis for intentional action and interaction with the environment.

Evidence and criticism

Testability
Dennett’s IllusionismConceptually testable
Searle’s Biological NaturalismEmpirically testable in principle, as the theory requires finding the exact causal details of how lower-level brain processes cause consciousness.
Tests so far
Dennett’s IllusionismNot stated
Searle’s Biological NaturalismThe theory is generally supported by empirical evidence from neuroscience showing the link between consciousness and brain activity (e.g., brain impairment, brain stimulation).
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.
Searle’s Biological NaturalismCritics dispute the claim that the causal connection between brain states and consciousness is fully established. Tension exists in maintaining materialism while arguing consciousness is ontologically subjective and irreducible to objective physical processes.

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)
Searle’s Biological Naturalism
  • The Rediscovery of Mind (1992)
  • Biological naturalism (2007)
  • What things are conscious? (2007)

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