Meditations on First Philosophy

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Meditations on First Philosophy

• René Descartes, 1641

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Meditation 1

• What can be called into doubt

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• Descartes overall project in the Meditations to
  put human knowledge on a secure foundation
• Observes that in his youth he believed many
  falsehoods
• Has decided to raze everything to the ground and
  build up from more secure foundations
• Procedure withold assent not just from
  propositions he believes to be false, but also
  from ones he cant be absolutely certain of

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• Skeptic one who doubts
• Descartes is not a skeptic in the end, but he
  entertains skeptical doubt
• Dialogue with a skeptic, in a single voice
• Again, wants to build up from new foundations
• Whats the old foundation? The senses

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Stage 1 Doubt The Senses

• The senses deceive us sometimes, so we should
  never trust them
• Examples of deception by the senses Optical
  illusions, hearing things wrong, etc.
• An attempt to resist this doubt Can I really
  doubt that I am sitting here by the fire, etc.?
• Pressing the doubt A madman might think all that
  in error, and I might be mad

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Stage 1 Doubt, contd

• Resisting But I dont resemble a madman and
  anyhow if Im mad theres no point carrying on
  with this argument!
• Pressing But I could be dreaming that I am
  sitting by the fire etc.
• Resisting But even if I am dreaming, I can be
  sure that the elements of my dream-images are
  real

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An Argument by Analogy

• In paintings we find images of things that arent
  real
• These images are composed from images of things
  that are real
• Or at least, from elements of images of things
  that are real, like colors

• In dreams we find images of things that arent
  real
• These images are composed from images of things
  that are real
• Or at least, from elements of images of things
  that are real, like extension, shape, size,
  number

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Whats left after Stage 1 Doubt

• Conclusion of the argument by analogy we can be
  sure at least that the simple, universal building
  blocks are real
• So maybe well be OK if we stick with those
  intellectual pursuits that deal only with these
  simple elements, namely arithmetic and geometry
• Whether I am awake or asleep, 2 and 3 added
  together make 5, and a square has only 4 sides

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Stage 2 Doubt Arithmetic and Geometry

• Stage 1 doubt leaves untouched our certainty that
  2 3 5, and that a square has 4 sides stage 2
  doubt is of precisely that.
• Pressing God is omnipotent, so could He not
  have made it the case that, on the one hand, I
  believe that 2 3 5, and on the other, that 2
  and 3 do not make 5?

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Stage 2 Doubt, Contd

• Resisting But an omnibenevolent God would not
  deceive me thus!
• Pressing We know that we are deceived sometimes,
  so it is consistent with Gods goodness to
  deceive us. Why then couldnt He deceive us about
  arithmetic?
• Resisting There must be something wrong with the
  idea that God has so much power to deceive Ill
  withold my belief from this notion of God, and
  then I can at least be certain that 2 3 5

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• Pressing You wont achieve any certainty that
  way! For if theres no omnipotent God, the cause
  of your existence is something imperfect. If you
  can go wrong when the cause of your existence is
  a perfect, omnipotent God, still more can you go
  wrong when the cause of your existence is
  something imperfect. Anyhow, you can go wrong
  either way!

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Temporary victory for the Skeptic (recap)

• If there is an omnipotent God, I can be wrong in
  thinking that 2 3 5
• If there is no omnipotent God, I can be wrong in
  thinking that 2 3 5
• Therefore, I can be wrong in thinking that 2 3
  5
• So I can be certain of nothing there is not one
  of my former beliefs about which a doubt may not
  properly be raised

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Resisting the Temptation to Believe

• Descartes now has reasons to doubt everything
  that he believes
• But he finds that these reasons are inadequate to
  overcome his habit of believing various highly
  probable opinions
• To keep himself on a straight path, he invents
  the malicious demon

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The Malicious Demon Argument

• It is possible that a malicious demon is
  systematically making me believe only falsehoods
• So it is possible that all my beliefs are false
• So I have reason to doubt all my beliefs

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Meditation 2

• The nature of the human mind, and how it is
  better known than the body

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What are you?

• The resident of xxx Main street
• The second child of Jane and John Doe
• The one wearing the red shirt
• The subject of this experience (of a tension
  headache, a slight itch between the shoulder
  blades, etc.)
• The author of the thought Im now having, namely
  that Descartes was no slouch
• The subject of the feeling Im now experiencing,
  namely one of happy nostalgia

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• One powerful idea about what you are you are
  what you see when you introspect
• Two ways to inquire about the self, and its
  relation to the body
• What am I thinking about when I think about
  myselfis it something physical, or what?
• Are mental phenomena like thinking and feeling
  part of the physical world?

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Setting the scene

• Our hero, youll recall, is floundering in a
  maelstrom of doubt
• He wonders is there even one thing of which he
  can be certain?
• Let his doubt be granted the full scope he gave
  it in Med I the deliverances of his senses and
  of his reason are in question

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• Is Ds own existence in question, then, too? No
  If I convinced myself of something then I
  certainly existedI must finally conclude that
  this proposition, I am, I exist, is necessarily
  true whenever it is put forward by me or
  conceived in my mind.

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• But what is this I? It must be purged of any
  uncertainty
• A rational animal? No good. (Whats rational?
  Whats animal?)
• He used to think of his body when he thought of
  himself
• He used to think also of his capacities to move
  around, to be nourished, to sense and to think

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• As for his soul, it was something tenuous, like
  a wind or fire or ether, which permeated his
  more solid parts

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What survives the Malicious Demon Argument?

• Only thinking Thought this alone is
  inseparable from me. I am, I exist that is
  certain. But for how long? For as long as I am
  thinkingI am, then, in the strict sense only a
  thing that thinks

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Imagination rejected as a source of self-knowledge

• Is there more to the self than being a thinking
  thing?
• Perhaps he can use his imagination to discern
  whatever else there might be
• Imagination faculty of contemplating the image
  of corporeal things
• But all that he can be certain of in himselfthat
  he is a thinking thingdepends in no way on
  imagination

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What is a thinking thing? (A soul, for Descartes)

• A thing that
• Doubts
• Understands
• Affirms and denies
• Is willing and unwilling
• Imagines
• Has sensory perceptions

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Is a thinking thing really all that?

• Doubting, understanding, affirming/denying , and
  being (un)willing all seem more naturally a part
  of thinking than imagining and having sense
  perceptions
• For remember that imagining was simply
  contemplating the shape of a corporeal thing
• If the self is something of which he can be
  certain, it must be independent of the corporeal
  realmthe realm of bodiesof which he cannot be
  certain

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Appearance vs. Reality

• The power of imagining can be divided into the
  power of imagining and the experience of
  imagining, on the one hand, and the objects of
  imagination, on the other
• Same for the senses theres the experience of
  sensing, on the one hand, and things in the world
  which cause those experiences (or not), on the
  other

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• The first component in eachthe experiential
  componentbelongs to the mental realm it does
  not depend on having a body
• I certainly seem to see, to hear, and to be
  warmed. This cannot be false what is called
  having a sensory perception is strictly just
  this,and in this restricted sense of the term it
  is simply thinking.

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The ball of wax

• Still he cannot shake the sense that knows
  concrete physical things better than the
  puzzling I
• Consider, then, a piece of wax
• Most of what you think you know about it changes
  when it melts
• So what you really know about it is something
  that doesnt change its extended, flexible,
  changeable

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Seeing with the eyes, seeing with the mind

• He thought he saw the wax with your eyes, but all
  he really know about it he understood
• Cf. Seeing hats and coats, understanding them to
  be men

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• If I judge that the wax exists from the fact
  that I see it, clearly this same fact entails
  much more evidently that I myself also exist.
• If you judge, understand, know x, you exist
• So your belief in your own existence is better
  confirmed than any of your other beliefs!