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CAS LX 502 - PowerPoint

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									CAS LX 502 Semantics
8b. Propositional attitudes 7, 9

Propositional attitudes
The door is  I think Pavarotti is hungry.
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We discussed the morning star is the evening star

Bond is hungry
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Bond is hungry.
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A proposition. Either true or false, relative to a given situation. A sentence.

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Language has the capacity to embed one sentence within another. I think/hope/heard Bond is hungry.

Bond is hungry

Bond is not hungry

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The natural thing to suppose about
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I think Bond is hungry
Bond is hungry Bond is not hungry

I think/hope/heard Bond is hungry.

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is that the sentenceembedding verbs think etc. relate the thinker (Experiencer) to a proposition. Bond is hungry need not be true for I think Bond is hungry to be true. It’s just that worlds compatible with my beliefs are those in which Bond is hungry.
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(The actual world need not be within the worlds compatible with my beliefs.)

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That is: I think Bond is hungry is true in any world w in which my beliefs in world w are such that any world I believe is a candidate for the actual world is also a world in which Bond is hungry. That seems pretty straightforward— except what do we make of a sentence like: I believe that 1+1=2. ?

I think Bond is hungry
Bond is hungry Bond is not hungry

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I think 1+1=2
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Well, 1+1=2 is true all the time. Point one: This is kind of contentless. Point two: 1+1=2 is true in all the same worlds that 12345x67890=838102050 is. So it must also be true that I think 12345 x 67890 = 838102050. In fact, everyone must think both of these things, as well as any other mathematical truth. I think 1234x67890=8. I think 1=0.

1+1=2

I think 1+1=2
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We’ve reached a rather hard problem. A similar one:
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Pat wants to marry Lynn. Pat wants to marry Chris.

1+1=2

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If want does something like set up a relation between Pat and the set of worlds in which Pat’s desires are met, one must be true while the other is false (if we presuppose that the two are mutually exclusive).

Where to go from here?
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I think 1+1=2. I think 12345x67890=838102050. Pat wants to marry Chris. Pat wants to marry Lynn.

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Another case Portner mentions:
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Day-care provider: Noah cries all the time. Grandmother: Weihan is perfectly behaved. Trusting hearer: I accept your statements. Unbenownst to TH: Noah and Weihan are the same kid.

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Ideas?

My guess
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This is a literature that I am not that familiar with, so I don’t know what the philosophers have said about it. However. Clearly, we need to differentiate between:
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I think 12345x67890=838102060. I think dogs are not dogs.

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The pathological case is the first one. Perhaps it is a failure of reference, which might also be able to capture the Noah/Weihan case as well.

My guess
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Noah refers to a baby. Weihan refers to a baby. If I use Weihan to refer to a different baby than I use Noah to refer to, then I have one of the names wrong. It seems possible, though, that one can have names wrong. Given that, perhaps we can make headway with the math question by supposing that it’s possible to get the names wrong there too…

My guess
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Tracy believes that 4+5=9 and 4x5=23. There’s a sense in which Tracy doesn’t “understand” multiplication. Tracy believes that “x” is a (ditransitive) verb that relates 4, 5, and 23. There could be such a verb. It’s just not what mathematicians refer to as “x”. But it’s the verb Tracy uses, and named “x”. Then, it is not necessarily true that if Tracy believes that 4x5=23, Tracy also believes that 4x5=22. If we insist that everything is a name, …?

My guess
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There is a certain flexibility with names anyway in intensional contexts…
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I dreamt that I was Prince Charles and you were Harry Potter and we were in a leaky canoe, trying to return a wayward capybara to its birth parents.

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Perhaps a proposition carries not only information about truth conditions but also information about F (the naming function)?

De re vs. de dicto
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Trying again: de re vs. de dicto:
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Pat thinks that the mole is wearing a green shirt.

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Premise: Essentially a drawn-out game show where players work as a team to win money, but one is a plant there to foil their efforts. De dicto belief: belief about description.
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Pat thinks whoever the mole is, s/he is wearing a green shirt.

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De re belief: belief about individual(s).
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Pat thinks Chris is wearing a green shirt. Chris happens to be the mole.

De re vs. de dicto
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Pat thinks that the mole is wearing a green shirt.

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De dicto: The mole is part of Pat’s thought. De re: The mole is not part of Pat’s thought, but of my assertion.
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Tracy claimed Pat thinks that the mole is wearing a green shirt.

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The mole: my assertion
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Chris is wearing a green shirt Thinks Pat According to Tracy Lynn is wearing a green shirt Thinks Pat According to Tracy, who claims the mole is Lynn. But it’s Chris.

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The mole: Tracy’s statement
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De re vs. de dicto
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This seems to arise from the relativization to another possible reality, belief worlds, thought worlds, dream worlds. Substitution is possible where the referents are the same in the reality under evaluation.
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Pat thinks Chris is wearing a green shirt. Pat thinks the mole is wearing a green shirt.
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Same if in Pat’s belief worlds Chris and the mole have the same referent. (de dicto) Same if in reality, Chris and the mole have the same referent. (de re)

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