philosophy discussion4

2/13/2018

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• It was thought that epistemic intuitions vary from culture to

culture, so we can’t trust them as a guide to the true nature

of knowledge as such; at most our intuitions only track our

own parochial conception of what counts as knowledge.

• There are several problems with the design of the

experiment, but nonetheless these are striking results.

What should we make of them?

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Possible replies:

• Westerners and people from the Indian subcontinent have

difference concepts of knowledge.

• In evaluating these results, researchers themselves rely on

epistemic intuitions about what counts as good evidence for

what, what counts as an adequate experimental set-up, etc.

• More recent studies show that across demographic groups,

lay people share similar epistemic concepts with

philosophers, recognizing a difference between knowledge

and justified true belief.

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Proposal: Eliminating False Evidence

Proposal: The failing within Gettier cases is the evidence’s

being partly mistaken. Knowledge is justified true belief well

supported by evidence, none of which is false. Only true beliefs

can be epistemic reasons/evidence/justification.

Schematic illustration of Gettier’s first case:

[true] A. The boss says “Jones gets the job.”

[false] B. Jones gets the job.

[true] C. The person who gets the job has 10 coins.

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But demanding that no justification may depend on any false

premise is both too weak (problem #1) and too strong (problem #2).

Problem #1: There are Gettier cases where no false evidence is

used. Suppose the true proposition

(e) The man who will get the job has ten coins in his pocket.

is derived not from the false proposition

(d) Jones will get the job, and Jones has ten coins in is pocket.

but from the true proposition:

(d*) A reliable source said that Jones will get the job, and Jones

has ten coins in his pocket

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Problem #2: Intuitively one can know something despite the

existence of something non-ideal in the epistemic pedigree of

the belief in question (examples: faulty reasoning, false

premise, problematic testimony).

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Handout Case. Counting with some care the number of people

present at his talk, Alvin reasons: “There are 53 people at my talk;

therefore my 100 handout copies are sufficient.” The premise is

false. There are 52 people in attendance -- Alvin double counted

one person who changed seats during the count. And yet

intuitively Alvin knows his conclusion.

Proposal: Eliminating Defeat

• Proposal: The failing within Gettier cases is that some

pertinent truth is overlooked by the Gettierized evidence.

Knowledge is indefeasibly justified true belief.

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• Every cognitive perspective is limited. What happens to a

justified belief when the subject acquires additional true

information about the respective subject matter?

(i) S abandons the belief

(ii) S‘s justification for believing that p is weakened

(iii) S‘s justification for believing that p remains the

same

(iv) S‘s justification for believing that p gets a boost

• In Gettier cases, (i) or (ii) is the case. If Smith were to learn

that Jones doesn‘t get the job, he would cease to believe

that the man who will get the job has 10 coins in his pocket.

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• S's belief that p is indefeasibly justified if and only if there

are no additional true pieces of information q such that if he

came to believe q, he would no longer be justified in

believing that p.

• S knows that p if and only if

(a) p is true

(b) S believes that p

(c) S is completely justified in believing that p

(d) S’s justification is not defeated by proposition q

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Definition of a defeater: Justification r for proposition p is

defeated by proposition q if and only if:

(i) q is true truth condition

(ii) If S were to entertain the thought that q, S would

be completely justified in believing that q is false

justification condition

(iii) If S were to believe that q is true, this would

undermine his complete justification r

incompatibility condition

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Problems with Defeasibility:

1) The defeasibility theory is vague. Defeaters weaken

justification. But how weak, exactly, can justification for a

belief become before it is too weak to sustain the belief’s

being knowledge?

2) Since there are always some truths whose addition to the

belief set would destroy justification, the defeasibility

theory is a form of infallibilism.

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Proposal: Eliminating Inappropriate

Causality

• Proposal: The failing within Gettier cases is that the true belief

is caused too oddly or abnormally to be knowledge.

• S knows that p (where “p” stands for an empirical proposition)

if and only if

(i) p is true

(ii) S believes that p

(iii) there is an appropriate causal

chain connecting the facts that

make p true with S’s believing

that p

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• In Gettier cases the appropriate causal relation is absent.

What causes Smith to believe that the person who will get

the job has 10 coins in his pocket is not the fact that makes

his belief true (viz., the fact that Smith himself gets the job

and has 10 coins in his pocket) but something else (viz.,

the fact that the boss said that Jones gets the job and the

fact that Smith counted the coins in Jones’s pocket).

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1st Problem with Causal Theory: Deviant Causal Chains:

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Earthquake example: Steve is in Japan. He is at a newsstand.

Suddenly, a newspaper falls off the rack. Steve sees the headline. It

reads, "Earthquake hits Japan." Steve now believes that an earthquake

has just hit Japan. Steve’s belief is justified because he saw the

headline. What’s more, it is actually the case that an Earthquake just hit

Japan. Thus, Steve’s belief is true. But the newspaper Steve read is

actually 30 years old. But Steve’s belief that an earthquake just occurred

is caused by this earthquake, since the paper’s falling from the rack was

caused by an earth tremor resulting from the earthquake.

It is impossible to give a general definition of

deviant causal chains. For there is no such

a thing as a deviant causal chain per se. A

causal chain is deviant only relative to our

expectations and background knowledge.

2nd Problem with Causal Theory: Causation vs.

Reliability:

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Fake Barn example: Henry is driving in a part of the country where,

unbeknownst to him, the inhabitants have erected a large number of

fake barns, i.e., paper-mâché facades looking like barns from the

highway, yet lacking back walls or interiors. From the highway, these

fake barns are indistinguishable from real ones. Looking at what is

in fact a real barn Henry forms the belief that that is a barn. Does

Henry know that that is a barn?

• Most epistemologists think that Henry does not know that

that is a barn. Why?

• Henry holds a true belief but he could have very easily

ended up with a false belief. His belief is only accidentally

true; it‘s truth is not stable. If Henry had turned his head a

split second earlier or later he would have held a false

belief rather than a true one. It is a dangerous Gettier

case.

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• But Henry’s belief that that is a barn is appropriately

caused by the fact that that is a barn. The causal

condition on knowledge is satisfied.

• The Fake Barn example suggests that it is not enough

that the facts and the belief are causally related. The

facts and the belief must be reliably related.

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