Mind-Brain Type Identity Flashcards
Summarise the view of mind-brain type identity theory.
- Suppose there is only physical substance. Are thoughts and conscious experiences themselves types of physical property.
- Are mental properties, such as thinking about snow or feeling sad, also physical properties?
-One might argue, for instance, that they are simply neurological properties. E.g. to think about snow just is for certain neurons to fire in one’s brain.
- Mental properties just are physical properties.
- All mental states are identical to brain states (‘ontological’ reduction) although ‘mental states’ and ‘brain state’ are not synonymous (so not an ‘analytic reduction’).
How does MBTI describe physical properties?
- If we understand ‘physical property’ to cover all the properties investigated by the natural sciences, then there are lots of different kinds of physical property.
- E.g. a swan is a bird that is usually white. What makes it a bird (a biological property) and what makes it white (a colour property) are different properties, though both are physical in the broad sense.
What does MBTI say about mental substances?
-Mental events and states are very closely dependent on the brain, so many people now think that ‘the mind’ is just ‘the brain’, and everything mental is actually neurophysiological.
- The theory is called ‘type’ identity, because it claims that mental ‘types’ of thing (mental properties, states and events).
- Mental ‘things’ turn out to be ‘physical things’; I.e. mental properties are actually physical properties of the brain, mental states are brain states.
Why is type-identity theory an ‘identity’ claim and not a correlation?
- Smart argues the motivation for the theory is ockhams razor.
- Having size and having shape are correlated- everything that has a size has a shape and vice versa. But size and shape are distinct properties.
- So simply pointing out that everything has a particular brain state also has a particular mental state doesn’t show that mental states and brain states are the same thing. They could be two distinct things that occur together.
- Correlation is not identity.
What is the formal claim of MBTI?
P1. Neuroscience shows that mental properties are correlated with physical properties of the brain
P2. One explanation of this correlation is that mental properties are identical to physical properties of the brain.
P3. There are no strong reasons to Suppose that mental properties of the brain are distinct from the physical properties of the brain.
P4. Mental properties may be identical to physical properties.
P5. Ockhams razor: we should not multiply entities beyond necessity.
C1. Mental properties are identical to physical properties of the brain.
What are 3 Strengths of MBTI?
- The Problem of Other Minds- Type-identity theory makes one’s mental states potentially discoverable by brain scanning technologies.
- It arguably therefore solves the problem of other minds.
- Naturalistic Arguments- The purely physical origins, and physical constitution of each individual human being, and the material evolutionary origins of the species suggests there is no place for an immaterial mind.
- Minds don’t exist independently of certain complex biological arrangements of matter (I.e. brains).
-Ockham’s Razor- Reduction to the brain is to be preferred over dualism as the simpler theory so long as it explains the phenomena (at least as well as dualism).
-Outline the claim of MBTI
- Substances can have different sorts of properties- e.g. swan; bird (biological), (white colour).
- Type identity theory- Mental properties just are physical properties e.g. thinking a thought is exactly the same thing as certain neurons firing.
- Identity is not correlation- e.g. hearts and kidneys, size and shape.
- Neuroscience can only establish correlations- appeal to Ockhams razor: don’t multiply entities beyond necessity.
What is an ontological reduction?
- The things in one domain (e.g. mental things) are identical with some of the things in another domain.
- There is nothing more to a mental property than being a particular physical property.
- This is not conceptual or ‘analytic’ reduction:
- The claim is not that ‘pain’ means ‘the firing of nociceptors’
- But that two distinct concepts pick out just one property.
How does MBTI use Ockham’s razor to form its theory?
- If there are no overwhelming arguments or proof of dualism, we shouldn’t posit extra entities to explain the mind. We can explain just as much about mental states by referring to the brain as we can by referring to a non-physical mind.
- For example, when I feel pain, certain areas of my brain get activated (let’s call them my c-fibres). And when my c-fibres get activated, I feel pain. This suggests they are the same thing. We don’t need to posit an additional substance.
- So, where a dualist would say the c-fibres and the pain are two separate substances, type-identity theory says they are the same physical thing (but different concepts).
- ‘Pain’ and ‘c-fibres firing’ describe the same thing in the world just as ‘lightning’ and ‘electrical discharge’ describe the same thing using different concepts.
- To put it another way, pain and c-fibres are type-identical.
What is the location problem to MBTI?
- If my c-fibres are firing, it’s presumably pretty easy to locate where this is happening. You could put me in an MRI scanner, for example, and find out the exact location of the c-fibres firing.
- But my pain doesn’t seem to have the same physical location. It seems like it’s somewhere else. If you locate my c-fibres it doesn’t seem like you’ve located my subjective mental sensation of pain.
- So the argument is something like this:
- If pain and c-fibres firing are identical then they must share all the same properties
- C-fibres have a precise physical location
- Pain does not have a precise physical location
- Therefore, pain and c-fibres firing are not identical
What is the zombie argument against this theory?
- The zombie argument used against behaviourism can also be used against type identity theory.
- Remember, type identity theory says pain is identical to c-fibres firing. But we can imagine a zombie with the brain state (c-fibres firing) but not the mental state (pain).
What is Hilary Putnams challenge against MBTI based on multiple realisability?
- Hilary Putnam argues that mental states, like pain, cannot be reduced to brain states, such as c-fibres firing, because mental states are multiply realisable.
- What this means is that the same mental state can come from many different brain states.
- For example, an octopus has a very different brain setup to a human. Let’s say, for example, that octopuses have o-fibres instead of c-fibres.
- If you stabbed an octopus and it writhed about, surely you would say that it’s because it’s in pain. But if type identity theory is true, this isn’t possible.
- Multiple Realisability objection
- So the argument is something like this:
- If type identity theory is true, you cannot have the same mental state without having the same brain state
- An octopus and a human do not have the same brains or brain states
- But an octopus and a human can both experience the mental state of pain
- Therefore, type identity theory is false
- An example that Putnam uses is silicon-based aliens. If type identity is true, then we can’t both share the belief “grass is green” because my brain is made from carbon and its brain is made from silicon.
- But this just seems wrong. We both share the same belief despite our differing physiology.
