Epistemology: The Nature of Knowledge

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EpistemologyThe Nature of Knowledge
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What Is Epistemology?

• Epistemology the study of knowledge and related
  things (e.g. justification and belief)
• Some main questions of epistemology
• What is knowledge?
• Do we have any knowledge?
• What should I believe?
• How can I come to know things?

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Senses of Know

• Do you know John? He knows how to fix computers.
  I told him about your computer problems so he
  knows that you need help.
• 1st sense knowledge by acquaintance
• 2nd sense skill knowledge (know-how)
• 3rd sense propositional knowledge
• We care about 3rd sense.

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Propositional Knowledge

• Propositions claims, statements, etc. that we
  can believe, assert, etc.
• Ex Dallas is in Texas and Dallas está en
  Tejas mean the same thing, they express the same
  proposition.
• Propositional knowledge knowledge of
  propositions.

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Conditions for Knowledge

• Find nature by finding whats necessary and
  sufficient for knowing a proposition
• Necessary condition for x conditions that must
  be met for there to be x.
• Sufficient condition for x conditions that, if
  met, are enough for there to be x.
• S knows that p if and only if what?

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Belief Condition

• Suppose Kima doesnt at all care about whether
  waterboarding is torture. She has no beliefs
  about the matter.
• Suppose waterboarding is torture
• Can we determine whether Kima knows this, given
  the case so far?
• Yes. She doesnt know, b/c you have to believe
  the proposition in questionin order to know it.

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Belief Condition (cont.)

• What about when we say the following?
• I know, Obama won the election, I just cant
  believe it!
• Doesnt literally mean we dont believe it
• Just means were surprised(or something like
  that)
• Different (or just loose)sense of believe

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Truth Condition

• Some people think the earth is flat.
• But its not.
• Do they know that the earth is flat?
• No, b/c its false.
• One knows a proposition only if its true.

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Truth Condition (cont.)

• What about when we say the following?
• I just knew that McCain would win the election!
  (though he didnt)
• Just means I was confidentor thought I knew
• Different (or just loose)sense of know

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Is TB Enough?

• So justification and belief are necessary
  conditions
• But are they jointly sufficient?
• Suppose Omar believes hell win some money b/c
  his horoscope says so
• And he does win some money from a lottery
  ticket he forgot he bought

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Is TB Enough? (cont.)

• Did Omar know he was going to win ?
• No, b/c he isnt justified in believing anything
  just b/c his horoscope says so
• He doesnt have good evidence for his belief
• He lucked out

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Justification Condition

• One must be justified in believing the
  proposition in question.
• To be justified in believing something, you must
  have good evidence for it (good reasons for
  thinking its true).

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Traditional JTB Conception

• S any subject or person
• p any proposition
• JTB analysis of knowledge
• S knows that p if (and only if)
• S believes p,
• p is true, and
• S is justified in believing p.

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Is JTB Enough? Gettier Cases

• Kima is looking outside her window.
• She thinks she sees a bird on her fence.
• So she believes theres a bird on my fence.
• But some joker put a fake bird up there.
• But there is a real bird somewhere on the fence
  where Kima cant see.

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Is JTB Enough? (cont.)

• Kima has good evidence that theres a bird on her
  fence
• (shes looking at the fence in daylight with his
  glasses on, etc.)
• So shes justified in holding her belief.
• Does Kima know theres a bird on her fence?
• No, she just got lucky that there was a real one.

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Is JTB Enough? (cont.)

• Such cases were famously proposed as
  counter-examples to JTB conception
• by Edmund Gettier in 1963
• So, it seems JTB are necessary
• but not sufficient for knowledge

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Cartesian (JGTB) Conception

• S knows that p if (and only if)
• S believes p, p is true, and Ss justification
  for p guarantees the truth of p.
• This conception associated w/René Descrates
  (1596-1650)
• It requires 100 certainty that p.

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Worries for JGTB

• Do you know who the current president is?
• But couldnt Obama have died this morning?
• If he did, Biden would automatically be president

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Worries for JGTB (cont.)

• So your evidence doesnt guarantee that Obama is
  pres.
• There are many cases like this
• We know things w/o certainty
• So, JTGB seems too strong

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Where Are We Now?

• JTB seems insufficient
• JGTB seems too strong
• Whats just right?
• Recent epistemologists are working on
  figuringthat out