Transcript
Page 1: Descartes: Philosophy of Mind

Descartes: Philosophy of Mind

Unit 4

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Descartes’ Overall Conclusions•HE ARGUES FOR SUBSTANCE

DUALISM: MIND AND BODY ARE TWO ENTIRELY DISTINCT SUBSTANCES.

•HE ARGUES THAT THE MIND IS A BETTER KNOWER THAN THE BODY

•HE ALSO ARGUES FOR INTERACTIONISM: MIND AND BODY INTERACT CAUSALLY.

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Methodological Scepticism •Descartes says his

senses can’t be trusted because they often mislead us

•He gives the examples of dreaming and the deceitful demon.

•He says he can doubt what he sees, his memory, and even that he has a body.

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Argument 1: The Cogito•Descartes finds one thing he can be sure of.

•In order to have these doubts there must be something to do the doubting.

•Even if he is being deceived, he must exist in order to be deceived.

•He concludes “I think, therefore I am” - cogito ergo sum.

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Archimedes Analogy

•Descartes believes that the cogito was the foundation of all other knowledge (Foundationalism).

•Like Archimedes, who wanted to find a firm place from which he could move the entire universe, Descartes wanted to find a firm place to base all knowledge on.

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First Evaluation of the Cogito• Kierkegaard argues that the cogito is just

a tautology.• A tautology is any statement that is true

by definition. For example, “All sisters are female” or “All Bachelors are unmarried”.

• As such a tautology is really a useless statement because you are just repeating yourself or defining a word.

• Some people think that the cogito is a tautology because the word “thinking” already includes an “I”. The word thinking just means that a person must exist to do the thinking.

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Second Evaluation of the Cogito• Hume and Lichtenberg argue that Descartes is

not warranted in assuming that just because some thinking is going on there must be some person doing the thinking.

• There may be thinking without an “I”. • Lichtenberg argues that Descartes should not

say “I think, therefore, I exist” but “I think, therefore, thinking is going on”.

• However, Descartes responded to this by denying that the cogito was an argument.

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Third Evaluation of the Cogito• Russel argues that the word “I”

implies personal identity - an individual person that is the same throughout time.

• He says that Descartes has not proved that the thing which is currently doing the thinking is an “I” because he has not proven that it has personal identity.

• How does he know that the being that is doing the thinking is the same being today that it was yesterday or ten years ago.

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What is the “I”?

• He is a NOT man because this leads to too many other time consuming questions.

• He is NOT a body, as he cannot be sure he has a body.

• He is NOT a soul, which has the attributes of nutrition, sense perception, movement and thinking. Nutrition, sense perception and movement are all dependent on the body, which we cannot be sure of.

• This leaves only one alternative: he is a thinking thing (also an attribute of the soul)

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The “I” is also an Imagining and Sensing Thing • He could use the imagination to find out what other

things the “I” is. • However, Descartes says he can “invent” anything

in his imagination, even that which is not real. • Imagination also involves contemplating bodily

things and we cannot be sure of bodily things. • While Descartes cannot be sure that the things that

he imagines are real, he can be sure that he does imagine.

• While he can doubt the contents of his sense experiences, he cannot doubt that he seems to sense.

• He also doubts, understands, affirms, denies, wills, etc.

• All of these things are really just aspects of thinking.

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The Wax Argument • As the wax is heated and melts each of its sensory

attributes changes. • If we only had our sense experiences of the wax, we

would think that the wax in its original form was a different thing to the melted wax.

• Thus, the senses don’t enable us to know the wax, which is a flexible, changeable and extended thing.

• It is not through my imagination that I know the wax because we cannot imagine all of the infinite forms the wax might take.

• CONCLUSION: If sensory perception and imagination

have been eliminated, my mind alone must know the wax.

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Evaluation of the Wax Argument•Hume would say that our

senses see the wax transforming as it is heated and assume that it is the same piece of wax not two different pieces of wax – one hard and one melted. Hume would agree that the senses don’t give us certainty of the physical world but, as an empiricist, he thinks that we may not have certainty at all.

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The Coats and Hats Example • If Descartes looks out into the street, he may see

people walking about in hats and coats. • However, all he has really seen with his eyes is

some hats and coats; he hasn’t actually seen the people under them.

• His belief that there are people walking around in the street is actually an inference he has drawn using his judgment.

• Descartes says that judgment is an activity of the mind.

• Thus, his belief that there are people in the street is really an act of his mind not his senses or imagination.

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The Mind is Better Known than the Body •Descartes states that not only does his

mind know things more clearly than his body/senses, he also knows of his mind more clearly than he knows the physical world.

•After all, his perceptions of the piece of wax may be entirely illusory; however, when he is perceiving the piece of wax, he cannot doubt that he is perceiving, nor that he is understanding those perceptions through acts of the mind.

•Both the perceiving and the understanding prove that he exists.

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Mind/Body Dualism

•Thus, Descartes has divided his world clearly into two parts.

•The first is the mind, which is certain, non-physical, unchanging and not extended.

•The second is the extended material world, including the body, which is changing and is able to be doubted.

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Mind/Body Dualism cont

• (P1)I can conceive of myself being conscious in a world in which there are no material entities (including bodies).

• (P2) But, if I am conscious at a given time, then I exist at that time (Cogito).

• (P3) Therefore, I can conceive of myself existing without a body, without corporeal attributes.

• Thus, having a body is not an essential part of who we are, which is a thinking thing, a mind. Thus, mind and body are separate.

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First Criticism of Mind/Body Dualism •We know that mind and body

causally interact because our thoughts cause our behaviours.

•How can a non-physical entity, such as a soul, causally interact with a physical body?

•Descartes just claims that they interact without explaining how.

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Second Evaluation of Mind/Body Dualism• Just because the concept of mind is different from the

concept of body, it does not follow that mind and body are different substances.

• Ryle says Descartes has made a category mistake by thinking that mind and body belong in different categories when they are the in the same category.

• Ryle gives the example of a person who goes to Oxford University and is shown the buildings, parks, churches and people. After the tour he says “I have seen the buildings and people but where is the university?”. The person thinks the buildings and the university are two different categories of things when they are really the same thing.

• Likewise, just because our mind and body are separate things and we use different concepts to describe them it doesn’t follow that they must be made of two different substances.

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Third Evaluation of Mind/Body Dualism• If the essence of my being is thinking, and I

stop thinking (when asleep), then I must cease to exist.

•Descartes suggested in his Replies that I am just not always aware that I am always thinking.

•But isn’t this contradictory? If I am not aware of it how can I be certain that I am thinking?

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Armstrong’s Overall Conclusion

•Armstrong is a materialist. He believes that the mind is a material or physical thing.

•He is also an Identity Theorist. He believes that the mind is identical to the brain.

•Thus, he rejects Descartes Dualism.•Essay tip: This should be clearly stated in

your introduction, along with your answer to the essay question, your own opinion, etc.

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Armstrong: Philosophy of MindUnit 4

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Armstrong’s Overall Argument

P1. Mental states are the inner causes of behaviour.P2. The inner causes of behaviour are brain states and processes. Therefore: Mental states are identical with brain states and processes.

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Argument for Premise 2 • P1. Science is the only discipline where learned

individuals ever reach consensus. • P2. It is rational to believe what learned

individuals agree upon.• It is rational to believe what scientists agree

upon. 

• P3. Scientists agree that the causes of behaviour are neural (brain) states and processes.

• It is rational to believe that the inner causes of behaviour are neural states and processes.

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First Evaluation

•His view of science is questionable. Is science the only discipline that ever reaches consenses about what is true and are scientific truths that reliable anyway? (think about Kuhn and Nietzsche’s criticism of science).

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Argument For Premise 1: Traditional Behaviourism

• Behaviourism was the dominant materialist theory of mind in the 1950s.

• Traditional Behaviourism: The mind is not something behind behaviour, but simply part of the behaviour.

• Rejection: However, people can have certain mental states and not act on them. Thus, mind and body are not the same thing.

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Dispositional Behaviourism• Dispositional Behaviourists, like Gilbert Ryle, say that

mental states are dispositions to behave in certain ways. • They say that to have a certain disposition is just to say

how one would act if the conditions were right. • For example, to say that a vase is fragile is to say what

would happen to it if it were dropped, struck by a hammer, etc.

• Ryle is not saying that the vase itself has any inner properties that give it a fragile disposition and cause it to break.

• Ryle does not believe that dispositions are inner mental states that cause behaviour.

• Since he is still a Behaviourist, Ryle denies that mental sates are inner states. Like Traditional Behaviourists, he says mental states (dispositions) are the same as outward behaviour.

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Armstrong’s Analysis of Dispositional Behaviourism

• Armstrong states that when Ryle starts to talk about dispositions he does the very thing that Behaviourists are trying to avoid. That is, he suggests that mental states are something other than behaviour.

• If we can have a disposition without acting on it then dispositions and behaviour cannot be the same thing.

• Armstrong says that dispositions do seem to be something behind the behaviour, which causes behaviour.

• To say that a vase has a fragile disposition is to say that it has inner properties that would cause it to shatter if dropped.

• Likewise, to have an angry disposition doesn’t just mean you would act angry in certain situations it also means that you have an inner mental state that causes your behaviour.

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Why does Armstrong Analyse Behaviourism

•Armstrong believes that Behaviourism is problematic but a step in the right direction.

•Armstrong believes that while mental states cannot be identified with behaviours, mental states are linked to behaviours.  

•Armstrong believes that dispositions are the inner mental states that cause behaviour (premise 1 of original argument)

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Comparisons• Both Armstrong and the Behaviourists are

materialists. • Both Ryle and Armstrong think that mental

states are dispositions• In contrast to Ryle, Armstrong things

dispositions/mental states are inner properties that cause behaviour.

• Like Descartes, Armstrong thinks mental states cause behaviour, while Behaviourists thinks that mental states are behaviour.

• Unlike Descartes, Armstrong thinks that mental states are physical things (neurological processes).

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The Problem of Consciousness • Armstrong rejects a possible criticism of his theory, which

is that his theory of mind may not explain consciousness. • Consciousness is when we are aware of our thoughts and

actions as opposed to just acting without being aware of our thoughts and actions.

• Thus, consciousness seems to be more than just a disposition to behave in certain ways.

• As Armstrong says, automatic, habitual behaviour like automated driving, involves having dispositions to behave in certain ways but we are not conscious of what we are doing.

• A conscious driver would be more aware of what they were seeing and doing.

• What is consciousness then if it is more than just having dispositions that cause behaviour?

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Armstrong’s Solution• Consciousness is just a disposition to behave in certain

ways. However, it is a particular type of disposition.• We can chose to pay attention to our mental states or to

ignore them. When we pay attention to our mental states we are conscious.

• Conscious mental states are dispositions that are directed towards other inner states, and not towards the outside environment.

• The automated driver is not aware of their own mental states and thus is not fully conscious of what they are doing.

• If the automated driver had a disposition to pay attention to his mental states he would be conscious of them.

• Thus, consciousness is a disposition to scan one’s on mind – to pay attention to particular mental states.

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First Evaluation of Materialism• The Knowledge Argument for Qualia: The

knowledge argument is intended to show that a complete physical knowledge of the mind would fail to provide us with a complete knowledge of the mind.

• Thus, there must be some non-physical aspect of the mind.• Frank Jackson created a scenario commonly called “Black and White Mary” to explain this problem.

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Second Evaluation of Materialism

• The Impossibility of Artificial Intelligence: If the mind is a completely material thing the like the brain it seems logically possible that we should be able to replicate it (Turing).

• But Artificial intelligence is seeming more and more like an impossibility. Does this lend weight to the claim that we have some non physical soul like mind?

• In his “Chinese Room Argument”, John Searle argues that artificial intelligence is impossible because computers are not capable of understanding.

• Is there some non-physical part of the brain that scientists just can’t recreate?

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Evaluation of Materialism•Neuroscience, especially

brain scan technology, suggests that the mind is just the brain.

•Incidents of brain injury also back up materialism by showing how the personality is connected to the brain (Phineus Gage).

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Other Concerns with Materialism• If materialism is true we wouldn’t have

freewill because all physical things are subject to the laws of cause and effect.

• If materialism is true we wouldn’t have personal identity because all physical things change.

• If materialism is true life would be meaningless because we are mortal creatures.


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