EPM: Ch II

Pete MandikChairman, Department of PhilosophyCoordinator, Cognitive Science LaboratoryWilliam Paterson University, New Jersey USA

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Some Background: Mental States that are propositional attitudes vs. mental states that are notExamples of propositional attitudes: Believing that the grass is green Desiring that you win the lotto Knowing that two and two are fourExamples of mental states that are

not propositional attitudes: Feeling sad Fearing spiders Having a tingly sensationONLY PROPOSITIONAL ATTITUDES

CAN BE REASONS OR JUSTIFY KNOWLEDGE CLAIMS

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So maybe…sense datum talk (which

isn’t obviously about propositional attitudes) is really code for appearance talk (which is about propositional attitudes).

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The idea of a codeSymbols that (by stipulation) stand for sentences,

even though the symbol parts (also by stipulation) don’t stand for anything

Symbol: Stands for: All puppies are mammals

Symbol: Stands for: Some mammals are puppies

Symbol: Stands for: All mammals are puppies

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Question:Does entail ?

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Answer:NO! means nothing other than “all

puppies are mammals” means nothing other than “all

mammals are puppies” 3. “all puppies are mammals” does not

entail “all mammals are puppies”Therefore: does not entail

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Another exampleSymbol: There is a rock in my shoeStands for: The party is at the bar

Symbol: Something made of minerals is in my shoe

Stands for: You are invited to the party

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QuestionDoes “There is a rock in my shoe”

entail “something made of minerals is in my shoe”?

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Answer:NO!1. “There is a rock in my shoe” means

nothing other than “The party is at the bar”

2. “Something made of minerals is in my shoe” means nothing other than “you are invited to the party”

3. “The party is at the bar” does not entail “you are invited to the party

Therefore: “There is a rock in my shoe” does not entail “something made of minerals is in my shoe”

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Sense data talk as code for appearance (e.g. ‘looks’) talkSymbol: I have a red sense datumStands for: Something looks red to me

Symbol: I have a sense datum that is a determinate shade of red

Stands for: Something looks a determinate shade of red to me

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QuestionDoes “I have a red sense datum” entail

“I have a sense datum that is a determinate shade of red”?

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AnswerNO!1. “I have a red sense datum” means nothing

other than “something looks red to me”2. “I have a sense datum that is a

determinate shade of red” means nothing other than “Something looks a determinate shade of red to me”

3. “something looks red to me” does not entail “something looks a determinate shade of red to me”

Therefore: “I have a red sense datum” does not entail “I have a sense datum that is a determinate shade of red”

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Another exampleSymbol: “A plant has chlorophyll in it”Stands for: “A plant photosynthesizes”Question: Does “a plant has

chlorophyll in it” explain “a plant photosynthesizes”?

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AnswerNO!If P is just a code for Q, then P cannot explain

Q (because Q cannot explain Q)“a plant photosynthesizes because a plant

photosynthesizes” is no explanation at allIf “a plant has chlorophyll in it” does explain

“a plant photosynthesizes” then “a plant has chlorophyll in it” cannot be merely a code for “a plant has chlorophyll in it”.

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Analogously…If sense data talk is merely code for

appearance talk then sense data cannot constitute explanations of appearances

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Another thingLogical Positivists want to define all

physical objects and other people as logical constructions of sense data

If sense data talk is merely a code for the way things look or appear, then for the Logical Positivists to succeed they must be able to define all physical objects and other people as logical constructions of the way objects and people look or appear

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In other words…According to the Logical Positivists the

way things are can be constructed out of (and thus must be conceptually posterior to) the way things seem.

According to Sellars, as he will argue in the next chapter, the way things are cannot be constructed out of the way things seem because the way things are is conceptually prior to the way things seem

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THE END