Physicalism Mind/Brain Identity Theories

Designed to overcome the issues of causation with Cartesian Dualism - how the metaphysical can affect the physical (mental states having affect on the body) and similarly how the physical can affect the metaphysical (ingesting hallocinogenics)

Physicalsm is the view that all that exists is physical - that which possesses extension

Type-type identity theory suggests:Mental phenomena are identical to certain physcial phenomena ErgoHaving a mental state consists of being in a particular physical statePain = C-fibres firing

=

Reductive -Identity theory reduces mental states to physical states

As the pain I am feeling now is identical to C-fibres activity the pain I was feeling yesterday is also identical

Pros:SimpleOccam's Razor No need to account for relationship between physical and metaphysical - they are the same Science based

Weaker version of type-type

Every token of one type will be identical with a token of the second type

Timepiece Analogy

Various tokens of the timepiece can be found on people's wrists, mantelpieces, town halls etc. Every token of the timepiece will be identical in terms of physical parts designed to tell the timeHowever there is no single type of arrangement Could be digital, analogue etc.

Type-type applies in the case of scientific identities - water is always H2O Unduly restrictive in terms of mental states as it implies that mentality must be confined to human biological systems. What about Washoe?

Multi-realisability of mental states:In the case of stroke victims a mental function lost through damage to a particular area of the brain is sometimes reinstated when a different part of the brain takes over

Like how information can be stored in different forms: hard or floppy disks

Too Reductive?Hilary Putnam - 1967 Finding the cocktail of chemicals that relates to pain in humans is too narrow - it only works for humans Octopus brain may be completely different to human brain Octopus probably feel pain though

Leibniz's Law 1. Brain States and processes have spatial location2. Mental States and processes do not have spatial location3. Therefore mental states and processes cannot be brain-states and processes

What is it like to be a bat? Thomas Nagel 1974Mental states are privateBats have very different mental states to humansWe can only speculate about what it is like to be a batFrom the outside brain states appear to be physical processes whereas from an internal prospective they will be experiences as states of mindImpossible to avoid a duality of properties  

Intentional Mental States Most mental states possess intentionality I cannot just believe - I must believe somethingPropositional 'that' clause - 'I believe that...'

Type-Type

Token-token

Problems with both Mind/Brain Identity Theories