Head to head
Christian Soul Theory vs Functionalism
Christian Soul Theory and Functionalism, compared field by field from their entries in the Atlas.
At a glance
- Christian Soul Theory belongs to the Dualism family in Kuhn's Landscape of Consciousness, Functionalism to Materialism.
- Christian Soul Theory treats consciousness as fundamental; Functionalism treats it as emergent.
- On AI consciousness, Christian Soul Theory says “Unlikely” and Functionalism says “Yes”.
- On life after death, Christian Soul Theory says “Yes” and Functionalism says “Conditional”.
- On mind uploading, Christian Soul Theory says “No” and Functionalism says “Likely”.
- On meaning and purpose, Christian Soul Theory says “Cosmic/Ultimate” and Functionalism says “Humanistic only”.
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The claim
In brief
Christian Soul TheoryThis theory posits that the human person is composed of two fundamentally distinct substances: a wholly immaterial, substantial soul (the self) and a physical body or brain. The soul is the locus of consciousness, provides personal identity, and interacts with the body in a cause-and-effect manner.
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
Christian Soul TheoryConsciousness and the mind are grounded in the substantial, unified, wholly immaterial soul, which is the entity that has experiences and grounds personal identity.
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
Christian Soul TheoryUnlikelyIf consciousness requires a radically separate, nonphysical substance (soul) that is divinely created or allocated, non-biological intelligences could not generate this necessary component, making AI consciousness impossible.
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.
Christian Soul TheoryYesThe soul is the ‘real you,’ existing independently of the body and providing the clearest mechanism for the persistence of individual consciousness post-mortem, fulfilling the core tenet of Abrahamic religions.
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).
Christian Soul TheoryNoUploading neural patterns and pathways would only duplicate the physical basis of consciousness. Since the necessary nonphysical substance (the soul) would be absent from the duplicate, first-person mental self-preservation would be impossible.
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.
Christian Soul TheoryCosmic/UltimateAs a theological theory, it provides ultimate meaning, purpose, and value tied to divine creation, destiny, and the spiritual nature of human existence.
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
Christian Soul TheorySubstance Dualism. Reality consists of at least two ontological categories: physical (brain/body) and nonphysical (soul).
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
Christian Soul TheoryInteractionist: The immaterial soul relates to the physical body/brain in an informing and cause-effect way, meaning physical states cause phenomenal states, and phenomenal states cause physical states.
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
Christian Soul TheoryPrimitive. The soul is a substantial, nonphysical substance, often held to be created and allocated by God (Creationism) rather than arising from material processes.
FunctionalismEmergent. Consciousness arises from the functional organization realized by a sufficiently complex substrate (like neural tissue or computer chips).
Qualia
Christian Soul TheoryQualia (qualitative feel) are phenomenal properties borne by the immaterial soul, which provides the single, unitary awareness of complex experiences.
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
Christian Soul TheoryInteractionism, which requires that the physical world is not causally closed, allowing the nonphysical soul to exert causal power over the physical brain and vice versa.
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
Christian Soul TheoryThe non-extended soul is associated with the body, being fully 'present' at each point within it.
FunctionalismDistributed wherever the functional organization is successfully realized, regardless of whether the substrate is neural tissue or hardwired computing components.
What it does
Christian Soul TheoryThe soul's main functional role is providing causal efficacy for mental states (especially in relation to libertarian free will) and grounding personal identity. It also gives form to and animates the body.
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
Christian Soul TheorySpeculative/Philosophical. Direct empirical testing is impossible due to the soul’s nonphysical nature. It is argued that empirical evidence for survival beyond death (like NDEs/OBEs) would instantaneously falsify materialism and support dualism.
FunctionalismConceptually and empirically testable. Thought experiments (like substrate replacement) probe its conceptual limits, and computational realization (AI) tests its empirical application.
Tests so far
Christian Soul TheoryReported observations such as near-death experiences (NDEs) and out-of-body experiences (OBEs) are cited by adherents as phenomena requiring a nonphysical explanation, which the soul provides.
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
Christian Soul TheoryThe primary tension is the problem of mental causation (how an immaterial soul can causally interact with the physical body/brain) and the conflict with the widely accepted scientific principle of the causal closure of the physical world. Critics often attribute persistence in this view to 'folk myths' or persistent traditions.
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
Christian Soul Theory
- The Substance of Consciousness: A Comprehensive Defense of Contemporary Substance Dualism (2023)
- The Soul: How We Know It’s Real and Why it Matters, J.P. Moreland (2014)
- Mind, Brain, and Free Will, Richard Swinburne (2013)
Functionalism
- What is functionalism? (N. Block) (1980)
- What Is Functionalism? Consciousness, Function, and Representation (N. Block) (2007)
- Functionalism (J. Levin) (2023)