Epistemological
Preliminaries
Kareem Khalifa
Philosophy Department
Middlebury College
Overview
I.
II.
III.
IV.
What is a theory of knowledge?
The project of description
The project of explanation
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 knowledge
B. Necessary Conditions
C. Sufficient Conditions
D. Truth
E. Belief
F. 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.
Barb
Does 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 knowledge
I don’t believe
that a table is
here.
John
Does 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. Justification
B. Classical Account of
Knowledge
C. 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; and
3. 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 Value
B. Three Problems
C. 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.