Descartes Dualism

1
Descartes Dualism

• How are mind and body related?

2
Review Hyperbolic Doubt

• Achieved through three arguments, of increasing
  power
• Argument from sensory deception
• Dream Argument
• Evil Genius Argument
• Question Is Descartes ultimately successful in
  doubting all his former opinions?

3
Criticisms of the Dream and Evil Genius Arguments

• Dream Argument distinguish
• Believing while dreaming
• Dreaming that you believe
• Dream argument only works if (1) is the right
  description.

4
The Evil Genius Argument

• Is total deception possible?
• Think about the brain-in-the-vat possibility,
  where no one ever discovers that they are in the
  matrix.
• Is that deception?

5
Descartes Response

• Theres something that cant be doubted.
• That I exist as a thinking thing.
• Whats the argument?

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The Cogito

• Can I doubt my own existence?
• was I not, therefore, at the same time,
  persuaded that I did not exist?
• Far from it
• assuredly I existed, since I was persuaded.
• Doubless, then, I exist, since I am deceived.

7
The Cogito, continued

• Try doubting that you think.
• To do that you have to doubt.
• But the act of doubting is an act of thinking.
• So you are aware that you are thinking.
• So you fail at doubting that youre thinking.

8
Compare

• Can you truthfully say
• I am not here now
• (1) is a token-reflexive sentence. The meaning of
  I, here and now depend on the performance
  of the sentence itself.
• Can you ever truthfully assert (1)?
• Listen to my voice-mail message.

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What am I I who know that I am?

• I know I exist as a thinking thing.
• Do I know that I have a body?
• I might still be deceived about that.
• So its possible that I dont have a body.

10
What else do I know?

• I know whats going on in the mind.
• Do I know the wax?
• I know that Im having wax-like appearances.
  There may be no wax.

11
Mind and body are distinct

• I can imagine not having a body, and still
  existing.
• So, while it may be true that I have a body,
  having a body is not essential to thinking.
• And thinking is not essential to being a body.
• Therefore mind and body are distinct.

12
Descartes Dualism

• A dualist says that there are two kinds of
  substances, minds and bodies.
• A monist says that there is only one kind of
  substance.
• You can be a monist who says that there are only
  minds. (Idealism)
• You can be a monist who says that there are only
  bodies. (Materialism)
• Descartes is clearly a dualist.

13
In dualisms favor

• Minds are autonomous
• Minds are not just brains they are much more
  than that.
• Minds dont need bodies
• We could, in principle, exist without them.
• Thats good, since our bodies are finite!

14
Problems for dualism

• While dualism explains our first person
  (introspective) access to the mind, what about
  other minds?
• This is called The Problem of Other Minds
• and yet what do I see from the window beyond
  hats and cloaks that might cover artificial
  machines, whose motions might be determined by
  springs ? But I judge that there are human beings
  from these appearances, and thus I comprehend, by
  the faculty of judgment alone which is in the
  mind, what I believed I saw with my eyes.

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Another problem

• What can we know about the mind, on the dualist
  picture?
• Nothing via science, since science studies
  objective (not subjective) phenomena.

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How are mind and body related?

• If mind and body are radically different kinds of
  things, how can they interact?
• They do seem to interact
• Mental events cause physical events.
• Physical events cause mental events.

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Solutions to the interaction problem

• Descartes the pineal gland mediates.
• Occasionalism
• God mediates.
• Parallelism
• Theres no real interaction, just the appearance
  due to pre-established harmony. (Leibniz)

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Other problems

• Does Descartes give a positive characterization
  of the mind?
• Or does he just say that it is not physical, not
  in space, etc.?
• How is language and communication possible, on
  Descartes picture?
• How could you know what I mean when I say that I
  am in pain?