physicalism Flashcards
what is physicalism
Physicalist theories of the mind argue that the universe is made of just one kind of thing: physical stuff.
According to physicalism, everything that exists – including the mind and mental states – is either a physical thing or supervenes on physical things. This means that two physically identical things must be mentally identical.
The opposing view to physicalism is dualism – the view that there are two kinds of things: physical things and mental things.
Physicalist theories all agree that the mind is a physical thing (or supervenes on physical things). But they disagree about what kind of physical thing mental states are.
behaviourism
Behaviourism says the meaning of words used to describe mental states – such as ‘pain’, ‘sad’, ‘happy’, ‘think’ etc. – is all about what is externally observable, i.e. behaviour and behavioural dispositions.
So, for a behaviourist, the meaning of ‘pain’ is to wince, say “ouch!”, try to get away from the source of the pain, have an elevated heart rate, and so on. Notions of private inner sensations (e.g. qualia) are irrelevant to what ‘pain’ means – it’s all about the external and observable (i.e. behavioural) manifestations.
hard behaviourism
Hard behaviourism (e.g. Carl Hempel): All propositions about mental states can be reduced without loss of meaning to propositions about behaviours and bodily states using the language of physics
In other words, hard behaviourism says you can give a complete account of the mind purely in terms of actual behaviours and bodily states. If you completely describe a person’s physical state and behaviours, you have described their mind – there’s nothing left over. In the language of philosophy, hard behaviourism says mental states analytically reduce to behaviours (and other externally observable physical facts).
soft behaviourism
Soft behaviourism (e.g. Gilbert Ryle): Propositions about mental states are propositions about behavioural dispositions
In contrast, soft behaviourism says that propositions about mental states (e.g. “he is in pain”) are propositions about behavioural dispositions (see below).
behavioural dispostions
A disposition is how something will or is likely to behave in certain circumstances. For example, a wine glass has a disposition to break when dropped on a hard surface. The wine glass has this disposition even when it hasn’t been dropped and is in perfect condition because – hypothetically – if you dropped the glass, it would break.
gilbert ryle against dualism - catergory mistake
Ryle argues that to think mental states are distinct from their associated behaviours (as dualism claims) is to make a category mistake – it confuses one type of concept with another. For example, to ask “how much does the number 7 weigh?” confuses the concept of number with the concept of things that have weight.
Ryle gives the following example to illustrate why dualism makes a similar such category mistake: Suppose someone were to visit Oxford to see the university. The visitor is shown the library, the lecture theatres, the teachers, and so on. After the tour is complete, he says: “but where is the university?”
The visitor has made a category mistake in thinking that the university is something other than the things he’s been shown already. The visitor thinks the university is in the category of objects you can isolate and point to, but instead it’s more of an abstraction.
Ryle argues that dualists make the same sort of category mistake when talking about mental states.
Suppose an alien were to ask what the mental state of pain is. You show the alien people stubbing their toes, being tortured, wincing, saying “ouch!”, and so on. After showing the alien these examples of pain it asks: “but what is pain?”
In just the same way Oxford University is nothing more than the buildings, teachers, and so on, Ryle is arguing that the mental state of pain is nothing more than the various behavioural dispositions associated with pain. There is nothing you can show the alien over and above these behavioural dispositions.
super spartans against behaviourism
Philosopher Hilary Putnam develops the asymmetry argument further with his example of ‘super Spartans’.
Super Spartans are an imagined community of people who completely suppress any outward demonstration of pain. They don’t wince, flinch, say “ouch!”, or anything like that. They have no dispositions toward pain behaviour – their heart rate doesn’t even increase.
putnam super spartan
Both the normal human (left) and the super Spartan (right) feel pain internally, but the super Spartan shows no outward manifestations whatsoever
Nevertheless, we can imagine the super Spartans do feel pain internally. They might not show it externally, but they would still experience a subjective experience of pain if they were tortured, say.
Remember, behaviourism says pain is a disposition to behave a certain way. But here we have an example of pain without the associated behavioural dispositions. So, the two things – pain and the behavioural dispositions – are two separate things. So, if super Spartans are possible, then behaviourism is false: it’s possible to have the mental state without the behavioural disposition.
possible response to the problem of super spartans
The behaviourist could reply that without any sort of outward display it would be impossible to form the concept of pain. Without the concept of pain it impossible to distinguish which behaviour they were supposed to be suppressing in the first place. So Putnam’s example is incoherent.
ZOMBIES
The zombie argument for property dualism can also be used to argue against behaviourism.
A zombie is basically the exact opposite of a super Spartan: where the Spartan has qualia but not behaviour, the zombie has behaviour but no qualia. It might say “ouch!” when it gets stabbed but it doesn’t feel any pain internally.
If zombies are possible, then it’s possible to have the behavioural dispositions associated with pain without actually being in pain. Therefore, the behavioural disposition of pain is separate from the feeling of pain. Therefore, behaviourism is false.
multiple realisability against behaviourism
The same mental state can be realised through multiple different behaviours depending on a person’s other mental state. And these other mental states also need to be analysed in terms of behaviours, which again might vary depending on a person’s other mental states. This can go on forever.
For example, let’s say you and I could both have the mental state of being thirsty.
This mental state of being thirsty would probably cause you to behave by drinking a drink if it was in front of you. But I might not drink the drink – despite having the same mental state of being thirsty – if I also have the mental state of believing that the drink is poisoned.
So, in order to explain why the mental state of me being thirsty leads to this particular behavioural disposition (i.e. not drinking), we need to appeal to another mental state. But this additional mental state also needs to be analysed in terms of behaviour.
The mental state of believing that a drink is poisoned would probably cause you to behave by avoiding the drink or pouring it away. But someone else might drink the drink – despite also believing that the drink is poisoned – if they also have the mental state of being suicidal.
And the mental state of being suicidal can also be realised in multiple different behaviours depending on a person’s other mental states, and so on and so on.
Circularity objection to behaviourism
depending on other mental states
In short, it seems impossible for behaviourism to explain mental state as behaviours without assuming various other mental states. But these other mental states need a behavioural explanation too!
type identity
Type identity theory is perhaps the most obvious physicalist theory of mind. It says that mental states reduce to brain states. Put simply, mental states are brain states.
An example often used in philosophy of mind to illustrate brain states is c-fibres. To say someone’s c-fibres are firing is just technical shorthand for the brain state associated with pain. And so, a type identity theorist would say that pain is identical to c-fibres firing, in the same way that lightning is identical to electrical discharge.
jjc smart : sensations and brain processes - ontological reduction/contingent identity
JJC Smart claims that mental states and brain states are contingently identical. Another way of saying this is that mental states ontologically reduce to brain states (which is how the A level philosophy syllabus defines type identity theory).
Other examples of ontological reductions/contingently identical things are:
Lightning is electrical discharge
Water is H2O
This table is an old suitcase
These relationships are not merely correlations. It’s not like electrical discharge happens at the same time as lightning, or that the electrical discharge causes the lightning – the lightning and the electrical discharge are the same thing.
According to type identity theory, it’s the same story with pain and c-fibres – they just are the same thing.
However, ontological reductions like this are not analytic reductions, such as “a bachelor is an unmarried man”. “A bachelor is an unmarried man” is an analytic reduction because the opposite idea (i.e. a married bachelor) is a contradiction. In contrast, even though “lightning is electrical discharge” is true, there is no logical contradiction in saying “lightning is not electrical discharge”.
So, according to type identity theory, ‘pain’ ontologically reduces to ‘c-fibres firing’, but it doesn’t analytically reduce to it.
ockhams RAZOR
Note: Ockham’s Razor can be used as an argument against dualism and in favour of physicalism more generally. It’s not just an argument for type identity theory.
Ockham’s razor is a scientific/philosophical principle which says something like:
“Do not multiply entities beyond necessity”
A more colloquial formulation would be something like “the simplest explanation is the best”.
In practice what this means is that, if two theories make the same prediction, the theory that posits the fewest number of entities is likely to be the more accurate theory.
For example, back before it was widely accepted that the earth revolves around the sun, astronomers had to posit all these crazy forces and reasons to explain why planets and stars appeared in the sky when they did. This geocentric theory could make pretty accurate predictions. But the heliocentric theory made the same predictions using far fewer entities:
JJC Smart has a similar idea in mind when arguing against dualism: He argues that type identity theory can predict everything that dualism can, but type identity theory does so with one entity (the brain) rather than two (mind and brain).
problem with mbtit- location
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
problem with mbtit- ZOMBIES
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).