substance dualism

2 features of mental states

intentionality and qualia

intentionality meaning

the quality that makes a mental state about something

qualia meaning

certain mental states have a particular quality or ‘feel’ - phenomenal properties - indescribable, qualitative nature of mind phenomena

example of intentionality

it is sunny today

example of qualia

the feeling of sunlight on your skin

what makes qualia different from intentionality

they are non intentional

dualism

human beings are made of 2 basic substances - the physical (the body) and the mental (mind)

what do dualists argue

we cannot reduce the mind to the physical - the mind is clearly a distinct phenomenon, non-physical

monism/physicalism

humans are made of one type of substance/s - can exist on it’s own

descriptions of qualia

directly accessible via introspection, private, ineffable, intrinsic

2 types of dualism

substance and property dualism

4 types of physicalism

identity theory, behaviourism, eliminativism and functionalism

what do dualist theories say about the mind

mental properties are irreducible to physical properties - we will never be able to explain consciousness

difference between substance and property dualism

substance claims that minds are made of a different type of substance from physical properties (one physical one mental), property claims the mind is a property of the brain, however mental properties are non-physical and cannot be reduced to physical states

philosophical behaviourism

argue that when we ascribe mental states we are talking about what we can observe - mental states can be reduced to something physical - behaviour

substance dualism is also known as

cartesian dualism

3 points on substance dualism

• neither substance relies on the other to exist ie the mind could live on after the death of the body

• in this life the mind and body do interact

• interaction takes place in the pineal gland

descartes 3 arguments to prove his theory of substance dualism

arguments from doubt and the indivisibility and conceivability arguments

basis of descartes arguments

i cannot doubt my own existence (of mind) but i can doubt the existence of my body therefore i am not my body

indivisibility argument

p1 the body is divisible

p2 the mind is indivisible

c therefore the mind is not the body

was is the main argument of the indivisibility argument

that our bodies are divisible and therefore extended, whereas are minds are indivisible and therefore unextended - they cannot be the same thing as these are two incompatible properties

p1 of the indivisibility argument

we can divide the body - can be divided an infinite amount of times

p2 of the indivisibility argument

you cannot divide your mind, it is one single consciousness when you look into your own mind you cannot detect any other parts

what does descartes base his indivisibility argument on

leibniz’s law

what does leibniz’s law state

if two things share all of the same properties, they must actually be one thing, but if one has a property that the other lacks, they must be distinct things

example of leibniz’s law

“rishi sunak” and the ‘current prime minister’ are different names for the same things, so anything that is true for rishi sunak is true for the current PM, but if there was one thing true for Sunak that was not true for the current PM, we could prove they were different people

link leibniz’s law to the indivisibility argument

the fact that minds and bodies are not both divisible means they cannot be the same thing

criticism (2) of premise 1 of the indivisibility argument

not everything physical is divisible - there are things that cannot be divided - ie physical states that humans can be in which are indivisible like being too hot

criticism (1) of premise 2 - 3 points

1. we are capabel of self-deception, ie refusing a shameful desire, internal conflict

2. modern neuroscience has proved that when cutting the connection between two sides of the brain functioning, with the patient unaware - consciousness literally divided - brain lateralisation

3. hume argues that the mind is just a bundle of conscious experiences

descartes argument for the premise that the mental is not divisible

escartes believes that via introspection we can prove that the mind is indivisible - no gap between appearance and reality

possible words

a way the universe might have been - similar or different to ours

example of a possible world

world with different laws of physics

logical possibility

something is logically possible if it doesn’t involve any contradiction for example it is not conceivable for there to be round squares and therefore it is not logically possible - there is not possible world containing round squares

physical possibility

something is physically possible if it’s occurrence is consistent with the laws of nature that exist in the actual world

metaphysical possibility

a claim can be logically possible by not metaphysically possible - logically it was possible for scientists to say c6h12 was water but this is not metaphysically possible

conceivability argument

P1= If I can conceive of the nature of 2 things separately, they must be able to be separated

P2 = my mind = non extended and thinking

P3 = my body = extended and non thinking

  C = therefore, my mind + body can be separated

2nd criticisms of premise 1 of the conceivability argument (arnauld& metaphysical possibility)

what is conceivable may not be metaphysically possible - arnauld - you’ve never heard of Pythagoras or seen his proof then you probably can conceive of a right angle triangle that lacked this property - what we can conceive is not a good guide to what is actually possible - descartes ability to conceive of his mind without a body doesnt show that it is possible - he may be unaware

1st criticism of premise 1 of the conceivability argument (masked man)

arnauld argues that through the masked man fallacy, it can be possible to have an incomplete idea of something so that it appears as two when it is one, descartes idea of his mind may be incomplete - introspection suggests the mind is a realm of conscious experience - i am unaware of my body in this - yet the fact that i am unaware of my body being responsible of this consciousness doesn’t show that it isn't

masked man fallacy as descartes conceivability argument

p1 i recognise that batman is a masked crusader

p2 i recognise that bruce wayne is a playboy millionaire

c. therefore batman is not bruce wayne

descartes response to the 2nd criticism of premise 1 of the conceivability argument (masked man)

arnauld’s criticism only works if descartes understanding of his mind and body are wrong he claims he has clear and distinct understanding

counter to descartes counter argument to the 2nd criticism of premise 1 of the conceivability argument

ie heat and motion - appear very different, you would assume that they have 'different essences' - Heat in other words is reducible to motion

3rd criticism of premise 1 of the conceivability argument

a mind without body is not conceivable - if dualism is true there is no reason why i should not be able to leave my body - ie student in class but body is not present

3 criticism of premise 1 of the conceivability argument

1. masked man fallacy

2. minds and bodys are metaphysically possible, not physically -arnauld

3. a mind without a body is not conceivable

2 arguments against substance dualism

1. the dependance of mind on brain

2. evolutionary history

the dependance of mind on brain - substance dualism criticism

neuroscience suggests that our mental life relies on our brain - memories are clearly lost in the brain - sense of self - sensations and feelings are also linked to our brain, brain can be disrupted by drugs or trauma - destruction of brain would lead to destruction of consciousness

descartes response to the first criticism - the dependance of mind on brain - substance dualism criticism

was aware of how important the brain was for proper function “its principle functions are, nevertheless, formed in the brain” - recognised that the brain was the centre for us

criticism 2 of substance dualism - evolutionary history

humans are merely an extension of all other animals - share common dna - we cannot explain the theory of a non physical mind, descartes claims that humans are the only species with minds - how did these come from evolution - where did they come from, how did they attach to us - we have a nervous system like most other species - ours only differs in complexity and power