Physicalism

• Physicalism


  Everything is physical or supervenes upon the physical.
• Hard behaviourism (Carl Hempel)


  All propositions about mental states can be reduced without loss of meaning to propositions that exclusively use the language of physics to talk about bodily states/movements.
• Soft behaviorism (Gilbert Ryle)


  Propositions about mental states are propositions about behavioural dispositions (ie propositions that use ordinary language).
• The distinctness of mental states from behaviour (issue with behaviourism)

  • If behaviourism is true then it would follow that Super-Spartans don't feel pain.
  • Similarly it would follow that perfect actors displaying signs of happiness would actually be happy.
• Issues defining mental states satisfactorily due to circularity (issue with behaviourism)

  • A complete behavioural analysis of mental states would have to reduce all to talk of mental states to talk of behaviour.
  • However how a mental state manifests itself depends on other mental states.
  • Therefore the analysis cannot be completed without reintroducing mental state terms and each turn, leading to circularity.
• Issues defining mental states satisfactorily due to the multiple realisability of mental states in behaviour (issue with behaviourism)

  • The same mental state can manifest itself in a variety of different behaviours.
  • A complete behavioural analysis of mental states in terms of behaviours would be indefinitely long and could never be completed.
• The asymmetry between self-knowledge and knowledge of other people's mental states (issue with behaviourism)

  • Behaviourists are right to suggest that we learn about other people's mental states through their behaviour.
  • However, I do not need behavioural evidence to discover my own mental states. I can access this introspectively.
  • Behaviourism cannot explain this asymmetry, showing that it is a flawed theory.
• Mind-brain type identity theory


  All mental states are identical to brain states (ontological reduction) although the terms 'mental state' and 'brain state' are not synonymous (so not an analytic reduction).
• Issues with providing type identities (issue with MBTIT)

  • Mind-brain type identity theory cannot account for the fact that mental states are multiply realisable.
  • Someone who has suffered brain damage may regain certain functions using different parts of the brain.
  • Animals also experience certain mental states such as pain, despite having different brain structures to humans.
  • The theory is chauvinistic for only allowing humans to have mental states.
• Eliminative materialism (Paul and Patricia Churchland)


  Some or all common sense ("folk-psychological") mental states do not exist and our common sense understanding is radically mistaken.
• Our certainty about the existence of our mental states takes priority over other considerations (issue for EM)


  P1: When I look into my own mind, I am directly aware of my mental states.

  P2: It is absurd to deny the existence of what I am directly aware of.

  C: Therefore eliminativism is wrong to deny the existence of mental states.
• Folk psychology has good predictive and explanatory power (issue with EM)

  • Folk psychology is very successful in predicting and explaining human behaviour.
  • It is also universal and has endured throughout human history.
  • Furthermore it is used in modern clinical psychology e.g. talking therapies.
  • This makes it a better hypothesis than eliminative materialism.
• Eliminative materialism is self-refuting


  P1: Eliminativism claims that mental states, such as beliefs, do not exist.

  P2: But if beliefs do not exist then it is impossible to believe the theory is true, and if the language used to articulate the theory doesn't really express genuine propositions then it is meaningless.

  C1: Therefore according to eliminativism it is not possible to believe and coherently articulate eliminativism.

  C2: So the theory is self-refuting.