February 8, 2010
Mind-Brain Identity Theory
• Central state materialism
• Mind = central nervous system
• How can a physical being have mental awareness?
• Philosophers need to explain:
o Conscious awareness of the world
Armstrong talks about automatic drive
Being aware of anything in the world is a 2 part process: part of the
brain turns on and produces a bodily response
Could occur without you being aware of it
o Self-awareness of the world
• Mind is the brain. Scientists have figured out for each mind state there is a brain
• False – MBIT – for each kind of mental state you can be in there’s a certain part
of the brain that it is (ex. hearing your mothers name). For every mental state,
there is only one brain state. Two people can have the same thought if they have
the same brain structure. Isn’t true that a certain mental state is a certain
• Requires too much similarity in brain structure
• Only creatures with brains like ours can have mental states like ours – not
true ex. Hydrocephaly
• Mental states are not behaviours, dispositions or certain kinds of brain states
• Functional/casual roles
• Taking something as input and using it as output ex. can openers – taking a closed
can as input and producing an open can as output
• Names for roles or functions that can be performed Nagel
• “What Is It Like To Be A Bat”
• Every philosophical alternative to Decartes theory is wrong
• Objective state – person can be in that state and not know it even though other
people can know it (ex. having “I’m a douche” taped to your back)
• Subjective state – if a person is in a state, she can’t help but know it, but other
people might not know it (ex. Duncan being sad about his love life, being in pain)
• All Cartesian theories say mental states are one kind of another mental state
• If mental states are dispositions, anyone could be experts on other peoples mental
• If mental states are brain states – objective states, various medical detection tools
that know what you’re thinking better than you
• Nagel thinks mental states are subjective – ex. always know if you’re in pain,
love, etc. Other people don’t know, they’re just guessing
• Ex. Understand that Bruce Wayne = Batman, don’t understand what it means to
say pain is jelly undergoing neurological changes, Jesus is truth
• Ex. Know all objective facts about bats, but don’t know what it’s like to be a bat
subjectively. Only understand a bats mental life if you know what it’s like to be a
• More anatomically similar two beings are, the closer they are to knowing what it’s
like to be that being
• Essence of mental states? Subjective
• Being knows all about it, being studying from the outside might not.
Frank Jackson – March 1 , 2010
• Ex. Child raised from birth – never seen colours in the world, only in black and
• However, fascinated by colours – going to be worlds greatest colour scientist
• Just as good as detecting colours in the world as others
• Knows every objective fact about colour
• 20 – can see colours again. What is her reaction?
• More to the experience of seeing red than all the objective facts about red
Idealist – there is no physical universe, the world is a dream in your mind. If there is no
physical world, no causal interaction between mental states and physical states, no need
for explanation, because you’re just interacting with yourself. No need to explain
communication – just communicating with yourself.
Pure Physicalist – believes there are no such things as minds. Theory of the mind =
theory of nothing. Dennett
• Doesn’t know if the mind is mental or physical – objective or subjective. Do
people have minds?
• Assumption that people have minds is extremely useful in trying to predict
• Methodological behaviourist
• Change beliefs and desires = change behaviour
• Doesn’t matter if you actually have any of those things, people assuming you
have them allows them to predict and change your behaviour
• 3 Different things to try to understand things:
o Understanding the physics of the thing – exhaustive mapping of the brain.
Physical stance - adopt the attitude of understanding by knowing its
physical structure, trying to understand behaviour through the flow of
electrons, atoms, molecules, etc.
Ex. Chess playing computer – trying to beat the computer, takes a
physical stance. Would take forever to figure out the flow of
electrons, took thousands of engineers to make, etc.
Understand the program? Design stance – Predict what something
is going to do by understanding what it was designed to do. Would
take forever to map out by hand what the computer would do next.
Intentional stance – Make assumption the thing has beliefs and
desires and believe it will do what it can to fulfill those beliefs and
desires. The thing has intentions. Things it intends to do, believes
that doing them will fulfill its desires. Able to think strategically,
assume the computer has a mind.
o Ex. Going on a safari – see a tiger. Will it eat you?
o Physical stance – too long to map out the anatomy of the tiger
o Design stance – not God, don’t know the purpose of the tiger
o Intentional stance – any desire to eat something? Behaving in any way that
makes you believe that it thinks you are edible? Does it look like
something that’s hungry and wants to eat me?
• Does the computer have a mind? – Dennett thinks it doesn’t matter. Assumption
that it does allows you to predict its behaviour.
• No such thing as an definitively right answer to whether anything has a mind –
figure of speech
Take the intentional stance – if you do you will have success predicting behaviour March 3 rd
“No such thing as the mind” – idea that there is a mind is just a theory.
• Eliminative materialist – eliminates the mind with something material, namely the
1. The theory that people have minds is the oldest theory people have, like all old
theories it’s false (crazy people possessed by the devil, sickness caused by black
bile, etc.). Odds of being correct = very low
2. The theory can’t do what it was designed to do (predicting behaviour). Can’t
explain certain things, predict human behaviour (ex. why do we need to sleep?
How memory works, human behaviour) How memory works – non-physical
ghost attached to body, in the mental state of having a memory, but didn’t know
until asked (Designed to predict human behaviour) – theory is terrible at
predicting human behaviour.
3. As a theory it makes a conjecture – inside peoples heads are hopes, beliefs,
desires, ideas, thoughts, etc. Prove a theory true by finding these things – find a
brain instead. Won’t find pieces of the brain that correlate with actions, desires,
beliefs, etc. Should find little bits of the brain that correspond to beliefs, actions,
desires, etc., but you don’t.
• Claiming no one has ever had a belief, idea, thought, etc.
• Says no such thing as feelings, beliefs, hopes, dreams, etc. It’s obvious when I am
experiencing pain, seeing the colour red, desire to go to school, therefore wrong.
What you find obvious depends on what theory you hold on the world.
Psychological talk will be replaced with brain chemistry? (Ex. the closest thing to
depression is low serotonin)
o Churchland’s reply: What you think is obvious depends on what theory of
the world you believe. Theory of having mental states means you find
mental states. Have the folk psychology theory of the world.
• No such things as beliefs = no such things as truths. No such thing as truths = no
such thing as his theory being true. If his theory is right, his theory can’t be right
because it becomes self-refuting
o Churchland’s reply: Admits there are only tru