Head to head
Emergence vs Functionalism
Emergence (Principle of Consciousness) 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 life after death.
- On AI consciousness, Emergence says “Conditional” and Functionalism says “Yes”.
- On mind uploading, Emergence says “Conditional” and Functionalism says “Likely”.
- On meaning and purpose, Emergence says “Uncertain” and Functionalism says “Humanistic only”.
Add more theories to this comparisonCompare other theories
The claim
In brief
EmergenceEmergence is the philosophical claim that qualitatively new properties, such as consciousness or psychological states, arise from underlying physical properties governed entirely by physical laws. It is distinguished primarily into weak emergence, which is reducible in principle, and strong emergence, which is fundamentally non-reducible and may necessitate new physical laws.
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
EmergenceConsciousness is identified as a qualitatively novel property or psychological state arising from physical properties. This concept defines the relationship between mind and matter based on reducibility or non-reducibility to fundamental physics.
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
EmergenceConditionalIf consciousness is weakly emergent, AI consciousness is certain given sufficient complexity. If strongly emergent, AI consciousness is still possible if non-physical properties emerge from non-biological physical complexity, depending on the meta-psychophysical laws involved.
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.
Does consciousness survive death?Both agree
EmergenceConditionalWeak emergence, being close to Materialism, precludes survival. Strong emergence, particularly in the form of Emergent Dualism, could theoretically generate a nonphysical substance (mind/soul) dependent on, but not strictly identical to, the physical brain, allowing for potential independent existence after death, although this is speculative.
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).
EmergenceConditionalIf consciousness is weakly emergent, duplicating the physical states would duplicate the mental states (likely). If strongly emergent, the non-reducible properties and possible downward causation would need to be perfectly captured and recreated in the new medium, posing significant, perhaps insurmountable, technical and conceptual challenges.
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.
EmergenceUncertainEmergence, especially strong emergence combined with concepts like top-down causation, offers a framework where higher-level properties like consciousness and its associated values could possess genuine causal power, potentially supporting cosmic purpose or meaning, depending on the resulting ontology.
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
EmergenceHighly variable/Contested. Weak Emergence supports reductive Physicalism. Strong Emergence often implies Non-Reductive Physicalism or a need to expand the conception of nature, potentially requiring new fundamental laws (Naturalistic Dualism or Property Dualism).
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
EmergenceEmergentist. The mind arises from the body (complex physical systems). The nature of the relationship depends on the type of emergence: Weak suggests reduction in principle; Strong suggests non-reducibility even in principle, often involving downward causation.
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
EmergenceEmergent
FunctionalismEmergent. Consciousness arises from the functional organization realized by a sufficiently complex substrate (like neural tissue or computer chips).
Qualia
EmergenceQualia are the novel, qualitatively new properties (e.g., sensory qualities) that arise from the physical system. Strong emergence views consciousness (and thus qualia) as the clearest case of a strongly emergent phenomenon, fundamentally irreducible to underlying physical facts.
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
EmergenceThe principle is the claim that novel, qualitatively distinct properties arise at higher levels of complexity, which is often contrasted with the reductive assumptions of mainstream science.
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
EmergenceTypically localized in complex biological systems (e.g., brains), although strong emergence proponents may argue that AI consciousness is possible if sufficient physical complexity is achieved, regardless of substrate.
FunctionalismDistributed wherever the functional organization is successfully realized, regardless of whether the substrate is neural tissue or hardwired computing components.
What it does
EmergenceVaries. Weak emergence aligns with standard physical causation. Strong emergence often posits top-down causation, where emergent higher hierarchical levels exert causal force on lower levels, giving the emergent property causal powers.
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
EmergenceSpeculative and philosophically contentious. Weak emergence is scientifically aligned in principle. Strong emergence is difficult to test empirically because it posits phenomena are non-deducible from fundamental science.
FunctionalismConceptually and empirically testable. Thought experiments (like substrate replacement) probe its conceptual limits, and computational realization (AI) tests its empirical application.
Tests so far
EmergenceNot stated
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
EmergenceIt is criticized by reductive physicalists (like Eliminative Materialists) as having little explanatory value, being superfluous, or acting as a 'restatement of a miracle' that fails to explain *how* unconscious complexity yields consciousness. Strong emergence specifically challenges the causal closure of the physical world.
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
Emergence
- The Re-emergence of Emergence: the Emergentist Hypothesis from Science to Religion, P. Clayton and P. Davies (2008)
- Strong and weak emergence, D. Chalmers (2008)
- Why reductionism does not work, G.F.R. Ellis (2019)
Functionalism
- What is functionalism? (N. Block) (1980)
- What Is Functionalism? Consciousness, Function, and Representation (N. Block) (2007)
- Functionalism (J. Levin) (2023)