Head to head
Frankish’s Illusionism vs Functionalism
Frankish’s Illusionism and Functionalism, 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 meaning and purpose.
- On AI consciousness, Frankish’s Illusionism says “Possible” and Functionalism says “Yes”.
- On life after death, Frankish’s Illusionism says “No” and Functionalism says “Conditional”.
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The claim
In brief
Frankish’s IllusionismKeith Frankish holds that conscious experiences are real but not what they seem: the irreducibly subjective ‘phenomenal properties’ or qualia we ascribe to them are an introspective illusion. Introspection builds a simplified, schematic model of the brain’s complex reactions to stimulation, and we mistake that model for direct awareness of inner qualities, so the hard problem gives way to an ‘illusion problem’.
FunctionalismFunctionalism posits that mental states are defined by their causal relations to one another, to sensory inputs, and to behavioral outputs, independent of the physical medium (substrate) in which they are realized. The essence of consciousness is determined by how mental states function or operate, rather than by what they are materially composed of.
What consciousness is
Frankish’s IllusionismConscious states are complex functional states of the brain that sustain rich sensory engagement with the world and flexible control of behavior. Their distinctive features are functional, which Frankish calls quasi-phenomenal properties.
FunctionalismMental states are identified as functional states, constituted by their causal relations, roles, results, and outputs, implying they are realizable in any substrate that supports those functions.
Big questions
Can AI be conscious?Differ
Frankish’s IllusionismPossibleSince consciousness is a complex functional state, a system with the right reactive and sensory organization could have it, though Frankish does not address machines directly.
FunctionalismYesFunctionalism holds that consciousness is based on function, not biology. If the correct functions can be realized computationally in non-biological substrates, AI consciousness is possible in principle and certain if Materialism is true.
Frankish’s IllusionismNoSince conscious states are functional states of a living brain, they end when the brain stops functioning.
FunctionalismConditionalAs a physicalist theory, consciousness is tied to the substrate. Survival beyond death of the biological body is only possible if the functional mental state can be successfully transferred (uploaded) to a new, continuing substrate (virtual immortality).
Frankish’s IllusionismNo position
FunctionalismLikelyFunctionalism serves as the theoretical basis for virtual immortality. If the functional role of the mental self can be perfectly duplicated and uploaded to a new medium, the first-person mental self is preserved.
Does it give life meaning?Both agree
Frankish’s IllusionismHumanistic onlyFrankish grounds value in what creatures are motivated to seek or avoid and argues that illusionism widens ethical concern to other animals across a graded ‘consciousness space’.
FunctionalismHumanistic onlyFunctionalism describes the mechanism by which mind/consciousness operates within a physical world, providing capacities for agency and reflection, but offers no rationale for ultimate cosmic meaning or teleology, aligning with the general stance of Materialism.
Nature of mind
Ontology
Frankish’s IllusionismPhysicalism (strong illusionism)
FunctionalismPhysicalism (broadly, agnostic to substance). The theory is classified under Materialism, but it is metaphysically agnostic regarding nonphysical substances, focusing primarily on the functional description of mental states.
Mind and body
Frankish’s IllusionismConscious experiences are physically realized functional states. Phenomenal properties are intentional objects, represented but never instantiated, like the impossible objects Nicholas Humphrey compares them to.
FunctionalismMental states are functional states identical to the functional roles that are realized or instantiated in a physical substrate, leading to 'functional state identity theses'.
Fundamental or emergent
Frankish’s IllusionismEmergent
FunctionalismEmergent. Consciousness arises from the functional organization realized by a sufficiently complex substrate (like neural tissue or computer chips).
Qualia
Frankish’s IllusionismQualia do not exist. Introspection misrepresents brain states, as perception misrepresents some features of the world, and introspective information bound to perception makes external things seem to carry vivid sensory qualities, such as an apple’s redness, that reflect their significance for us.
FunctionalismThe theory traditionally struggles to account for phenomenal qualia, often addressing them by asserting that the qualitative feel is entirely exhausted by the functional role, or by coupling with representational theories.
How it works
Mechanism
Frankish’s IllusionismThe reactivity schema: introspective systems track the overall psychological impact of stimulation without representing its detail, and this simplified model is mistaken for direct acquaintance with qualities. Frankish borrows Daniel Dennett’s image of a computer’s user illusion, whose icons have no literal counterparts in the machine.
FunctionalismThe principle of multiple realizability, stating that mental state realization is independent of the physical substrate, contingent only upon the required function being instantiated.
Where it is
Frankish’s IllusionismDistributed across the brain. The subject of the illusion is the whole organism, and the work of registering and reacting to it is shared among many unconscious subsystems, with no Cartesian theater.
FunctionalismDistributed wherever the functional organization is successfully realized, regardless of whether the substrate is neural tissue or hardwired computing components.
What it does
Frankish’s IllusionismConscious states guide flexible, intelligent behavior. The illusion itself is made of physical representations and so has causal effects, which may be adaptive, as Nicholas Humphrey argues; this avoids the threat of epiphenomenalism.
FunctionalismFunctions, roles, and outputs are dispositive. Mental states are causally effective because they are defined by their causal relations within the system (functional role).
Evidence and criticism
Testability
Frankish’s IllusionismConceptually testable
FunctionalismConceptually and empirically testable. Thought experiments (like substrate replacement) probe its conceptual limits, and computational realization (AI) tests its empirical application.
Tests so far
Frankish’s IllusionismFrankish holds that the reactive changes constituting experience are in principle experimentally detectable, which opens the experiences of other creatures to study.
FunctionalismThe silicon chip replacement thought experiment is used conceptually to test whether phenomenal consciousness is preserved when the functional role is maintained across a change in substrate.
Criticisms
Frankish’s IllusionismThe central objection, a version of Descartes’ cogito, holds that our own phenomenal states are indubitable data. Galen Strawson argues that illusionism denies the main source of ethical value. Others object that an illusion needs an audience.
FunctionalismIt is criticized heavily for failing to account for phenomenal consciousness (qualia) by describing only the functional role, leading to the 'hard problem' challenge that functional roles may not exhaust the nature of conscious experience.
Sources
Key sources
Frankish’s Illusionism
- Frankish’s Illusionism (Landscape of Consciousness), Keith Frankish (2021)
Functionalism
- What is functionalism? (N. Block) (1980)
- What Is Functionalism? Consciousness, Function, and Representation (N. Block) (2007)
- Functionalism (J. Levin) (2023)