introphil_lecture_slides_IntroPhil2-week2-slides

Another

Gettier-Style Case

The Sheep

You believe that there is a sheep in the field.

You are justified in believing that there is a sheep in the field. It is true that there is a sheep in the field.

But you don’t know that there is a sheep in the field because, unbeknownst to you, what you are looking at is a big sheep-shaped rock which is obscuring from view a sheep hidden behind.

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A Formula for Inventing Gettier-Style Cases

Step One

Take a belief that is formed in such a way that it would usually result in a false belief, but which is justified nonetheless.

Step Two

Make the belief true, albeit for reasons that have nothing to do with the subject’s justification.

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Patching up the

Classical Account:

No False Lemmas

Keith Lehrer (b. 1936)

One can know a proposition if, only if:

(i)That proposition is true;

(ii)One believes that proposition;

(iii) One’s belief is justified;

(iv)One’s belief is not based on any false assumptions (or ‘lemmas’).

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Problems for the

No False Lemmas Proposal

The no false lemmas proposal needs to offer a principled account of what constitutes a lemma such that:

•It is not so broad as to exclude bona fide cases of knowledge.

•It is broad enough to explain why Gettier cases aren’t case of knowledge.

This is easier said than done!

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Two Questions Raised by Gettier-Style Cases

(1) Is justification even necessary for knowledge?

(2) How does one go about eliminating knowledge-undermining luck?

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Part Two Conclusions

•The classical account of knowledge holds that knowledge is justified true belief.

•But Gettier cases demonstrate that knowledge is not justified true belief.

•Nor is knowledge justified true belief plus some obvious extra condition.

•So what is knowledge?

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Part Three

Do We Have any Knowledge?

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The sceptic says that we cannot rule-out sceptical hypotheses, and thus argues that we are unable to know anything about the world around us.

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The Brain-in-a-Vat

Sceptical

Argument

1.I don’t know that I’m not a brain-in-a-vat.

2.If I don’t know that I’m not a brain-in-a- vat, then I don’t know very much.

C. So, I don’t know very much.

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Brains-in-Vats

Question: Why don’t we know that we’re not brains-in-vats?

Answer: Because we can’t tell the difference!

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