Introduction to Philosophy EXAM 1

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Section 7.3 What Do You Know?

Knowing What Knowledge Is

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7.3-2

Traditional Analysis of Knowledge

 Knowledge is justified true belief.

 S knows a proposition P if and only if:  P is true,

 S believes that P is true, and

 S is justified in believing that P is true.

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7.3-3

Gettier’s Guy in Barcelona

 Suppose Smith has strong evidence for the claim that Jones owns a Ford but doesn’t know where his friend Brown is.

 So he concludes that (h) Either Jones owns a Ford or Brown is in Barcelona.

 It turns out that Jones does not own a Ford, but Brown is in Barcelona.

 Even though Smith is justified in believing (h), he doesn’t know (h).

7.3-4

The Defeasibility Theory

 Knowledge is undefeated justified true belief.

 Diagnosis of the Gettier problem: there is additional evidence which, if known, would defeat the knowledge claim.

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7.3-5

Thought Experiment: Lehrer and Paxson’s Demented Mrs. Grabit

 Suppose Lehrer sees someone who looks like Tom Grabit steal a book from the library.

 Mrs. Grabit, however, testifies that it was his twin brother John who stole the book.

 This piece of evidence defeats your claim (d) that Tom stole the book.

 But unbeknownst to you, Mrs. Grabit is a compulsive liar. So you do know (d) despite the defeaters.

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The Causal Theory

 Knowledge is suitably caused true belief.

 Diagnosis of the Gettier problem: what makes the claim true is not what caused the person to believe it.

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7.3-7

Thought Experiment: Goldman’s Fake Barns

 Suppose that Henry is driving through the countryside and points out to his son “That’s a barn.”

 Suppose it is a barn, but suppose further that there are a number of fake barns in the area.

 Even though the son’s belief that the object is a barn is caused by a real barn, he doesn’t know that it is.

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The Reliability Theory

 Knowledge is reliably produced true belief.

 Diagnosis of the Gettier problem: the beliefs were not produced by reliable means.

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7.3-9

Thought Experiment: Lehrer’s Human Thermometer

 Suppose Mr. Truetemp has a thermometer implanted in his skull that causes him to have reliable beliefs about the temperature.

 Suppose further that Mr. Truetemp never checks his temperature beliefs.

 Even though his beliefs are reliably produced, they don’t constitute knowledge.

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Virtue Perspectivism

 An intellectual virtue is a skill or ability that reliably produces true beliefs, like perception, memory, and reason.

 Virtue perspectivism claims that knowledge is apt belief—belief that is taken to be true because of one’s intellectual virtue.

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7.3-11

Evaluating Performances

 A performance is accurate if it achieves its goal.

 A performance is adroit if it manifests the skill of the performer.

 A performance is apt if it’s accurate because it’s adroit.

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Knowledge as a Performance

 The goal of knowledge is true belief. So:  A belief is accurate if it’s true.

 A belief is adroit if it manifests the intellectual virtue of the believer.

 A belief is apt if it’s believed to be true because of that virtue.

 Only apt belief is worthy of being considered knowledge.

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7.3-13

Animal Knowledge vs. Reflective Knowledge

 Animal knowledge is apt belief.

 Reflective knowledge is belief that we know to be apt.

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Virtue Perspectivism Solutions to Gettier-type Problems

 Gettier’s Guy in Barcelona has neither animal nor reflective knowledge because his belief is not apt.

 The subjects in Goldman’s fake barns and Lehrer’s Human Thermometer have animal knowledge but not reflective knowledge.

 The subject in the Demented Mrs. Grabit may have both animal and reflective knowledge.