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Descartes’s Substance Dualism vs Seth’s Beast Machine Theory

Descartes’s Substance Dualism and Seth’s “Beast Machine” Theory, compared field by field from their entries in the Atlas.

At a glance

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Dualism Descartes’s Substance Dualism René Descartes
Materialism Seth’s “Beast Machine” Theory Anil Seth

The claim

In brief
Descartes’s Substance DualismRené Descartes holds that consciousness, which he calls thought (cogitatio), is the essence of an immaterial thinking substance (res cogitans) wholly distinct from extended, mechanical body (res extensa). Every conscious state, from reasoning and willing to pain, color, and emotion, is a mode of the thinking thing and is immediately present to it. Sensations and passions, though, arise only in the union of mind and body, where brain processes stand in regular relations to experiences they do not resemble.
Seth’s Beast Machine TheoryThis theory posits that conscious experiences, including perceptions of the world and the self, are forms of brain-based perceptual prediction, metaphorically termed 'controlled hallucinations' . It roots the mechanism of consciousness in the fundamental biological imperative to regulate bodily physiology in order to stay alive .
What consciousness is
Descartes’s Substance DualismConsciousness is thought, defined as everything that happens within us insofar as we are immediately conscious of it, and it is the principal attribute of the mind.
Seth’s Beast Machine TheoryConsciousness is identified as forms of brain-based perceptual prediction, where phenomenological properties are explained by the computational aspects of different forms of prediction .

Big questions

Can AI be conscious?Differ
Descartes’s Substance DualismNoSince thought belongs only to immaterial substance and matter is pure extension, a machine, however complex, would be mechanism without a mind.
Seth’s Beast Machine TheoryLikelyAs a materialist theory focusing on computational and information-processing mechanisms (perceptual prediction) , AI systems that instantiate similar complex mechanisms should be capable of achieving consciousness .
Does consciousness survive death?Differ
Descartes’s Substance DualismYesDescartes presented the real distinction of soul and body as what makes the soul’s survival intelligible, and the Meditations announce that aim in their subtitle.
Seth’s Beast Machine TheoryNoConsciousness is a product of biological brains and complex, physically instantiated predictive machinery . The death of the brain leads to the irrevocable and permanent non-existence of personal consciousness .
Could a mind be uploaded?Differ
Descartes’s Substance DualismNoCopying the body’s mechanism would not copy the immaterial thinking substance.
Seth’s Beast Machine TheoryYesIf consciousness is entirely explicable by the computational processes of the brain , then, in principle, the first-person mental self could be duplicated and instantiated in a non-biological substrate, enabling virtual immortality .
Does it give life meaning?Differ
Descartes’s Substance DualismCosmic/UltimateDescartes’s system rests on a non-deceiving God who guarantees knowledge and created even the eternal truths.
Seth’s Beast Machine TheoryHumanistic onlyCategorized as a Materialism Theory, it implies no ultimate or cosmic meaning or purpose, although it supports human-created meaning and value derived from individual agency and experience .

Nature of mind

Ontology
Descartes’s Substance DualismSubstance dualism (Cartesian)
Seth’s Beast Machine TheoryPhysicalism / Materialism (Justified by its classification under Materialism Theories and its reliance on biological and computational explanations) .
Mind and body
Descartes’s Substance DualismMind and body are really distinct finite substances with exclusive essences, thought and extension, and could by divine power exist apart. They are joined in the human being, where bodily motions give rise to sensations and the mind moves the body, though Descartes never explained that interaction satisfactorily.
Seth’s Beast Machine TheoryConscious experiences are entirely brain-based and physically instantiated . The model supports a strong correlation or identity theory, where conscious properties arise from the physiological and computational architecture geared toward bodily regulation .
Fundamental or emergent
Descartes’s Substance DualismPrimitive
Seth’s Beast Machine TheoryEmergent
Qualia
Descartes’s Substance DualismSensory qualities are not properties of matter, which has only size, shape, motion, and arrangement. Experienced redness or pain is a mental mode arising in the embodied union and cannot be captured by extension.
Seth’s Beast Machine TheoryThe phenomenological properties of conscious experiences are explained by the computational aspects of the different forms of perceptual prediction utilized by the brain .

How it works

Mechanism
Descartes’s Substance DualismMechanism on the bodily side and non-reduction on the mental side. Light mechanically affects eyes, nerves, and brain, and the mind then experiences color, distance, and shape in regular correspondence with those motions.
Seth’s Beast Machine TheoryConsciousness is explained through predictive processing, where the brain generates a constant 'best guess' (prediction) of the causes of its sensory inputs . This mechanism is intrinsically tied to the regulation of bodily physiology .
Where it is
Descartes’s Substance DualismThe mind is unextended. Sensations and passions are felt as belonging to one’s own body, and Descartes located mind-brain communication in the pineal gland.
Seth’s Beast Machine TheoryLocated in the biological brain, tied to the predictive machinery that regulates bodily physiology .
What it does
Descartes’s Substance DualismPassions are caused and strengthened by movements of the animal spirits and dispose the soul toward volition and action. The will can in turn move the body.
Seth’s Beast Machine TheoryConsciousness has a functional role tied to survival . It facilitates the regulation of bodily physiology and allows the organism to model, predict, and simulate the causes of sensory inputs .

Evidence and criticism

Testability
Descartes’s Substance DualismConceptually testable
Seth’s Beast Machine TheoryEmpirically testable (Inferred, as the theory relies on concepts within the neurobiological and computational fields which emphasize development, testing, and comparison of theories) .
Tests so far
Descartes’s Substance DualismNot stated
Seth’s Beast Machine TheoryTests involving predictive processing accounts of brain perception, cognition, and action (Justified: Specific named tests are not provided, but the theory is explicitly positioned within the predictive processing framework) .
Criticisms
Descartes’s Substance DualismPrincess Elisabeth of Bohemia asked how an immaterial soul could move a material body, and the interaction problem remains unresolved. Arnauld and later critics charged circularity, since the proofs of God that guarantee clear and distinct perception themselves rely on clear and distinct perception. The standard reading denies consciousness to animals, which most now find implausible.
Seth’s Beast Machine TheoryNot explicitly detailed in the source, but generally subject to the tension inherent in deflationary accounts of consciousness .

Sources

Key sources
Descartes’s Substance Dualism
  • Meditations on First Philosophy, René Descartes (trans. J. Cottingham, R. Stoothoff, and D. Murdoch) (1984)
  • Principles of Philosophy, René Descartes (trans. J. Cottingham, R. Stoothoff, and D. Murdoch) (1985)
  • The Passions of the Soul, René Descartes (trans. J. Cottingham, R. Stoothoff, and D. Murdoch) (1985)
Seth’s Beast Machine Theory
  • Being You: A New Science of Consciousness, Anil Seth (2021)
  • Theories of consciousness, Anil Seth and Tim Bayne (2022)

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