Head to head
Higher-Order Thought Theory vs Tegmark’s State of Matter
Rosenthal’s Higher-Order Thought and Tegmark’s State of Matter, compared field by field from their entries in the Atlas.
At a glance
- Higher-Order Thought Theory belongs to the Materialism family in Kuhn's Landscape of Consciousness, Tegmark’s State of Matter to Neutral Monism.
- Both treat consciousness as emergent.
- They give the same kind of answer on life after death and meaning and purpose.
- On AI consciousness, Higher-Order Thought Theory says “Possible” and Tegmark’s State of Matter says “Yes”.
- On mind uploading, Higher-Order Thought Theory says “Possible” and Tegmark’s State of Matter says “Likely”.
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The claim
In brief
Higher-Order Thought TheoryDavid Rosenthal holds that a mental state is conscious when its subject has a higher-order thought that he or she is in that state, a thought that need not itself be conscious and does not seem to rest on inference. Mental qualities such as the redness of a sensation exist whether or not they are conscious; Rosenthal explains them separately, by how they map the perceptible properties we can discriminate.
Tegmark’s State of MatterTegmark proposes that consciousness can be understood as a specific state of matter, coined 'perceptronium,' which is defined by distinctive information-processing abilities. Starting from the premise that all existence is physical, the theory seeks principles that distinguish conscious, complex information processing from non-conscious processing.
What consciousness is
Higher-Order Thought TheoryA state’s being conscious consists in the subject being aware of it by way of a suitable higher-order thought that one is in that state.
Tegmark’s State of MatterConsciousness is identified as the subjective experience or 'feeling' that arises when information is being processed in certain complex ways, constituting the state of matter termed 'perceptronium'.
Big questions
Can AI be conscious?Differ
Higher-Order Thought TheoryPossibleSince consciousness depends on having suitable higher-order thoughts about one’s own states, a system able to form such thoughts would meet the condition in principle.
Tegmark’s State of MatterYesThe theory is strictly physicalist ('It's all physics') and defines consciousness as a state of matter achievable through complex information processing. Therefore, artificial systems can achieve this state in principle.
Does consciousness survive death?Both agree
Higher-Order Thought TheoryNoConscious states are natural states of an organism, so nothing remains conscious once those states stop occurring.
Tegmark’s State of MatterNoConsciousness is an emergent state of matter (perceptronium) of the physical brain. The irreversible death and dissolution of the physical substrate would entail the cessation of consciousness.
Higher-Order Thought TheoryPossibleIf the relevant first-order states and higher-order thoughts were reproduced, the view gives no principled reason the copy would lack consciousness.
Tegmark’s State of MatterLikelyIf consciousness is a specific informational state of matter defined by mathematical/physical principles, that state could potentially be perfectly duplicated or uploaded into a non-biological medium by advanced technology.
Does it give life meaning?Both agree
Higher-Order Thought TheoryHumanistic onlyThe theory is a naturalistic account of mental states and carries no cosmic purpose.
Tegmark’s State of MatterHumanistic onlyThe foundation in physics and mathematical structure typically suggests no ultimate cosmic purpose, consistent with deflationary physicalist views. The theory does not explicitly propose cosmic teleology.
Nature of mind
Ontology
Higher-Order Thought TheoryPhysicalism (naturalistic functionalism)
Tegmark’s State of MatterPhysicalism / Monism
Mind and body
Higher-Order Thought TheoryMental states, their qualities, and the higher-order thoughts that make them conscious are all natural states of the organism; Rosenthal expects neural correlates of consciousness to be whatever mechanism produces the higher-order awareness.
Tegmark’s State of MatterAn identity relationship is implied, where subjective experience (mind) is identified as a specific physical state (a state of matter/information processing).
Fundamental or emergent
Higher-Order Thought TheoryEmergent
Tegmark’s State of MatterEmergent
Qualia
Higher-Order Thought TheoryMental qualities are fixed by their role in perceptual discrimination and occupy a ‘quality space’ that mirrors the similarities among perceptible properties. Because these qualities do not depend on consciousness, a sensation can have qualitative character without being conscious, as in subliminal perception.
Tegmark’s State of MatterQualia are implicitly the 'feeling' (subjective experience) associated with perceptronium's specific information processing configurations, formalized through four principles: information, integration, independence, and dynamics.
How it works
Mechanism
Higher-Order Thought TheoryA non-inferential higher-order thought that one is in a given state, which makes that first-order state conscious even when the thought itself is unconscious.
Tegmark’s State of MatterThe definition of perceptronium via the application of four distinct principles (information, integration, independence, and dynamics) to information processing in physical systems.
Where it is
Higher-Order Thought TheoryNot stated
Tegmark’s State of MatterLocalized to physical systems (e.g., neural networks or arbitrary quantum systems) that achieve the specific information-processing criteria defining perceptronium.
What it does
Higher-Order Thought TheoryNot stated
Tegmark’s State of MatterConsciousness is crucial for information assessment and is viewed as functionally important for critical needs like caring for comatose patients or communicating with advanced AI. Causation is strictly physical.
Evidence and criticism
Testability
Higher-Order Thought TheoryConceptually testable
Tegmark’s State of MatterEmpirically testable
Tests so far
Higher-Order Thought TheoryNot stated
Tegmark’s State of MatterThe generalization of Integrated Information Theory implies relevance to IIT's measurement function (quantifying degrees of consciousness). The theory is intended to address concrete problems like assessing comatose patients and advanced AI.
Criticisms
Higher-Order Thought TheoryFirst-order theorists argue that higher-order awareness is an unneeded extra ingredient, and deflationists say being aware of a conscious state is like ‘smiling a smile’. Rosenthal replies that a deflated awareness cannot explain the contrast between conscious and unconscious states.
Tegmark’s State of MatterAs a generalization of IIT, it inherits existing critiques, such as the difficulty in explaining subjective feeling purely through physical and informational principles.
Sources
Key sources
Higher-Order Thought Theory
- Rosenthal’s Higher-Order Thought, Landscape of Consciousness, David Rosenthal (2005)
Tegmark’s State of Matter
- Consciousness is a state of matter (2015)
- Our Mathematical Universe: My Quest for the Ultimate Nature of Reality (2014)