Kareem KhalifaPhilosophy Department

Middlebury College

EpistemologicalPreliminaries

Overview

I. What is a theory of knowledge?II. The project of descriptionIII. The project of explanationIV. The value problem

I. What is the theory of knowledge?

• Epistemology literally means “theory of knowledge”

• What do good theories do?– Describe– Explain– Predict and control

II. Description

What is knowledge?A. Kinds of knowledgeB. Necessary ConditionsC. Sufficient ConditionsD. TruthE. BeliefF. No Luck

II.A. Kinds of knowledge

• Propositional Knowledge• Ability Knowledge• Knowledge by Acquaintance• The target: S knows that p

II.B. Necessary Conditions• Necessary condition on

knowledge: something that all knowledge has.– S knows that p only if

[INSERT NEC. CONDITION HERE]

• To show that X is unnecessary for knowledge, you must come up with an example in which:– S knows that p; and– X is false.

II.C. Sufficient Conditions

• Sufficient condition on knowledge: something that always results in knowledge.– If [INSERT SUF. CONDITION

HERE], then S knows that p.• To show that X is

insufficient for knowledge, you must come up with an example in which:– X is true;– S does not know that p.

II.D. Truth is necessary for knowledge

• S knows that p only if p is true.• What is truth? Tough question!

– Key idea: thinking that p doesn’t make p true.

Why truth is necessary for knowledge

There is a table here.

BarbDoes Barb know that there is a table here?

III.E. Belief is necessary for knowledge

• S knows that p only if S believes that p.• Belief = taking as true.• I know that it’s raining, but I don’t believe that

it’s raining.

Why belief is necessary for knowledgeI don’t believe that a table is

here.

JohnDoes John know that there is a table here?

III.F. No Luck

• So far, we’ve accepted that S knows that p only if:– p is true; and– S believes that p.

• But is this also sufficient?

• No.

III. Explanation

How do you know?A. JustificationB. Classical Account of

KnowledgeC. Gettier Problems

III.A. Justification

• S knows that p if and only if:– S’s true belief that p isn’t just

a lucky guess• But what does it mean not

to be a lucky guess?• To have justification

(reason, evidence) for one’s belief

III.B. The Classical Analysis• From Plato’s Theaetetus (c.

400 BC) until 1963 AD• A person S knows that p if

and only if:1. S believes that p;2. It is true that p; and3. S is justified in believing that

p• Often called the JTB (justified

true belief) account of knowledge.

III.C. The Gettier Problem

JTB is not always sufficient for knowledge.

Nearly universally agreed to have

refuted the JTB/Classical Account of Knowledge

Gettier’s Recipe

• Step 1: Take an agent who forms her belief in a way that would usually lead her to have a false belief.

• Step 2: Add some detail to the example to ensure that the agent’s belief is justified.

• Step 3: Put in some “fluke” which makes the belief true (even though usually it would be false)

An interesting objection to Gettier cases

• In the Gettier cases, Smith actually knows.• In this case, JTB entails knowledge.• One upshot of this: professional

epistemologists have atypical intuitions about cases of knowledge.

• If this interests you, then you should read some recent psychological research on this topic, as well as an interesting rebuttal to that research.

IV. Value

Why is knowledge valuable?A. True Belief’s ValueB. Three ProblemsC. Some Solutions

IV.A. True Belief’s Value

• Knowledge entails true belief.• True beliefs enable us to fulfill our goals (i.e.

true beliefs are instrumentally valuable.)• Being able to fulfill our goals is valuable.• So, knowledge is (instrumentally) valuable.

IV.B. Three Problems with this Explanation

1. True beliefs are generally instrumentally valuable, but not always instrumentally valuable.

2. Some true beliefs are about trivial matters, and are hence not valuable.

3. Even if true beliefs were valuable, why do we seem to prefer knowledge to merely true beliefs? (This is called the Meno Problem.)

IV.C. Solution to the Meno Problem

1. Knowledge is true belief + the absence of luck.2. True beliefs that are not merely lucky are more

“stable” than true beliefs that are lucky (i.e. true beliefs can’t easily be undercut or overturned.)

3. Stable true beliefs are more instrumentally valuable than unstable true beliefs.

4. So knowledge is more instrumentally valuable than merely true beliefs.

Recap• A theory of knowledge seeks to

provide necessary and sufficient conditions for when an individual has propositional knowledge.

• Truth, belief, and something else are needed to complete this theory.

• This theory should also answer “How do you know?” questions, and tell us why knowledge is more valuable than true belief.