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Armstrong’s Causal-Role Central-State Materialism
Mental States as Brain States Defined by Causal Role
Armstrong analyzes every mental concept as the concept of a state apt to be caused by certain stimuli and apt to cause certain behavior and further mental states. Science then finds that the states filling these roles are states of the central nervous system, so sensations, beliefs, and conscious experiences are brain states, not effects of brain states. Felt qualities get no separate ontological standing, which is where critics locate the explanatory gap.
David Malet Armstrong
What consciousness is
A mental state is the inner state that occupies a given causal role among stimuli, behavior, and other mental states. In humans those occupants are states and processes of the central nervous system.
Mind and body
Contingent, a posteriori identity. The mental occurrence and the neural occurrence are one event described through different concepts, discovered the way genes were identified with DNA or water with H2O.
Mechanism
A two-stage argument. A topic-neutral causal analysis defines each mental concept by its role, then empirical science identifies the role’s occupant with a brain state.
Core claims
- Mental states are inner causes of behavior, not behavior or behavioral dispositions, since pain can exist without withdrawal and a belief’s effects depend on other states.
- Mental concepts are topic-neutral: they specify what a state does and stay silent on whether its occupant is physical.
- Science shows that the occupants of these roles are neurophysiological states, so mental states are contingently identical with brain states.
- Armstrong presents the theory as a synthesis that keeps behaviorism’s link to behavior and dualism’s inner causes while rejecting immaterial substance.
Criticisms
Critics argue that a role-plus-realizer account states when experiences occur and are detected but leaves untouched why occupying a role should feel like anything, so Jackson’s knowledge argument and the explanatory gap survive the reduction. Armstrong’s treatment of qualia establishes an ontology more clearly than it explains subjectivity.
Implications
- AI consciousness: Possible
- The causal analysis is topic-neutral and allows other physical organizations to fill the same roles, so a machine whose states occupied them could count as having mental states.
- Survival beyond death: No
- Since mental states are states of the central nervous system, it follows from the view that they end with the brain.
- Meaning and purpose: Humanistic only
- Armstrong’s austere scientific naturalism leaves no place for cosmic purpose.
- Virtual immortality: Uncertain
- A copy might realize the same causal roles, but each mental state is identical with its particular physical realizer, so continuity of the person is not settled.
Related theories
- Smart’s Topic-Neutral Identity (Influence)
- Lewis’s Analytic Functionalism and Causal-Role Identity Theory (Overlap)
- Armstrong’s Higher-Order Perception Theory (Extension)
- Ryle’s Category-Dissolution of Inner-Theater Consciousness (Critique)
Sources
- Bodily Sensations, D. M. Armstrong (1962)
- A Materialist Theory of the Mind, D. M. Armstrong (1968)
- The Causal Theory of the Mind, D. M. Armstrong (1981)
- Qualia Ain’t in the Head: Review of Michael Tye’s Ten Problems of Consciousness, D. M. Armstrong (1995)
- Sensations and Brain Processes, J. J. C. Smart (1959)
- Psychophysical and Theoretical Identifications, D. Lewis (1972)
- Epiphenomenal Qualia, F. Jackson (1982)
- Armstrong’s Materialist Theory of Mind, P. R. Anstey and D. Braddon-Mitchell (eds.) (2024)