philosophy discussion4

profileValerielee
KnowledgeVersionofMooresParadox.pdf

2/19/2018

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Phil 2: Puzzles and Paradoxes

Prof. Sven Bernecker

University of California, Irvine

Knowledge Version

of Moore‘s Paradox

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“Omissive“ because it self-reports a lack of true belief.

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(I believe that p & not-p) ≡ (not-p & I believe that p)

(not-p & I believe that p) ≡ (p & I believe that not-p)

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Omissive form: p & I do not believe that p

Commissive form I: I believe that p, but it is not the case that p

Commissive form II: p & I believe that not-p

Moore‘s Paradox

Moore‘s paradox is the problem

of explaining why Moorean

statements cannot be sincerely

asserted without absurdity.

Knowledge Version of Moore‘s

Paradox

p & I do not know that p

• There are two explanations of the (putative) absurdity of this

statement. One explanation assumes that knowledge is the

norm of assertion -- Knowledge explanation. The other

explanation assumes that justification is the norm of assertion --

Justification explanation

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Knowledge Explanation

• Knowledge as the Norm of Assertion: Assert that p only if you know that p.

• Knowledge Distribution: Knowing a conjunction implies knowing each

conjunct.

• Factivity of knowledge: Whatever is known is true.

• Given the norm of assertion, if I assert that (p & I don‘t know that p), then I know

that (p & I don‘t know that p). Given knowledge distribution, if I know that (p & I

don‘t know that p), then I know that p. Given the factivity of knowledge, if I know

that (I don‘t know that p), then it is true that I don‘t know that p. Therefore, I do

and don‘t know that p. Contradiction!

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LiYuxi

2/19/2018

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Problems with the knowledge explanation of the knowledge

version of Moore‘s Paradox:

• Maybe the norm of assertion is not knowledge but rather

something weaker such as truth, perceived truth, reasonable

belief, justified belief etc.

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Justification Explanation

• Justification Principle: If one is justified in believing that p and one

knows that one believes that p, then one is justified in believing that one

knows that p.

• Norm of Sincerity: Assert that p only if you believe that p.

• Justification as the Norm of Assertion: Assert that p only if you are

justified in believing that p.

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• Given my conformity to the norm of sincerity and

justification, if I assert that (p & I don‘t know that p), I

am justified in believing that p. Given that I know

whether I am sincere, I know that I believe that p.

And given the justification principle, I am justified in

believing that I know that p. But this means that I am

not justified in believing that I do not know that p. But

I have also asserted that I do not know that p.

Contradiction!