Transcript Gettier Cases

Gettier Cases
Themes in Ethics and Epistemology
Shane Ryan
[email protected]
11/11/13
Issues
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Preliminaries:
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What is epistemology?

The JTB account of knowledge
Gettier cases: Having justified true beliefs but
lacking knowledge
Structure
1. What is the scope of epistemology?
2. What is the methodology of epistemology?
3. The JTB account of knowledge
4. Gettier cases
5. Conclusion
1. What is the scope of
epistemology?

Kvanvig (2005): epistemology is the study of purely
theoretical cognitive success. We focus on the intrinsic
features of cognition, and abstract from practical, political,
social, religious and moral consequences of cognition.


Epistemic goals include truth, knowledge, justification,
understanding, wisdom and rationality.
The focus of epistemology, however, is on the study of
knowledge.
1. What is the scope of
epistemology?
Different kinds of knowledge

Propositional knowledge: knowledge-that

“A proposition is what is asserted by a sentence which
says that something is the case”. (Pritchard, 2006: 3).

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Propositions may be true or false.
Examples:

“All bachelors are unmarried men.”
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“Paris is the capital of France.”
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“Democracy has become a sham.”
1. What is the scope of
epistemology?
Different kinds of knowledge
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Ability knowledge: know-how
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Example: Knowing how to ride a bike
Propositional knowledge and ability knowledge differ in that I may know
how to ride a bike but that does not imply that I know a set of
propositions about how to ride a bike.
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
Knowing how to do something.
My knowledge how to ride a bike is demonstrated by me riding a
bike.
Epistemology has been more concerned with propositional knowledge
1. What is the scope of
epistemology?
Another Useful Distinction
C. A. J. Coady (1992, 3) distinguishes what he calls positive
epistemology from negative epistemology. The former
investigates the structure of knowledge or the body of beliefs that
can reasonably be thought of as knowledge, and leaves sceptical
worries aside; while the latter is concerned with the theoretical
problems raised by scepticism.
Greco (2010, 5), similarly, distinguishes what he calls “the project of
explanation”, which seeks to explain “what knowledge is and how
knowledge is possible”, and “the project of vindication”, which is
the project “of showing that we have knowledge”.
2. What is the methodology of
epistemology?
Defining knowledge
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How can we define knowledge?
Approach I: Look at paradigm cases of
knowledge and identify what's common.
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Problem: But this just seems to assume that we
already have a criteria for knowledge that is right,
otherwise how could we identify such cases of
knowledge?
2. What is the methodology of
epistemology?
Defining knowledge

Approach II: Identify the criteria for knowledge.

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But this faces an analogous problem. I am only
able to do so if I can already identify instances of
knowledge.
This is the problem of the criterion.
2. What is the methodology of
epistemology?
Response
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We should either, (i) assume that we know or
through philosophical reflection alone can
identify the criteria (methodism),
or
(ii) we should assume that we can identify
particular cases of knowledge (particularism)
2. What is the methodology of
epistemology?

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(i) is mysterious while (ii) seems to require
assuming the sceptic is wrong.
Nonetheless contemporary epistemologists
tend to favour the second approach.

(Some claim that reflective equilibrium is ultimately
the right answers.)
3. The JTB account of knowledge
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The JTB account is an account according to
which knowledge is justified true belief.
According to the JTB account, justification,
truth, and belief are necessary and jointly
sufficient conditions for knowledge

S knows that p if and only if S has a justified true
belief that p.
3. The JTB account of knowledge
The conditions: Belief
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Entities lacking a mind can't have propositional
knowledge.
An entity that doesn't have beliefs can't be said
to know. And specifically, if one doesn't have a
belief that something is the case then one isn't
in a position to know that that is the case.
3. The JTB account of knowledge
The conditions: Belief
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In the case of propositional knowledge: If
Marina doesn't believe that it's raining outside,
then how can she be said to know that it's
raining outside?
(Beliefs may be occurrent (beliefs that we are
actually entertaining), while most of our beliefs
are non-occurrent.)
3. The JTB account of knowledge
The conditions: Belief
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Case: Walter comes home and sees that his house
has burnt down. He says “I don't believe it”, but he
sees it so can't he be said to know it?
The orthodox view is that what Walter says is not
strictly speaking true, rather what he says is best
understood as conveying that he finds it hard to
come to terms with what has happened. (Ichikawa
and Steup, 2012).
3. The JTB account of knowledge
The conditions: Belief

Radford's (1966) case:
“Suppose Albert is quizzed on English history. One of
the questions is: “When did Queen Elizabeth die?”
Albert doesn't think he knows [the suggestion being
that he doesn't believe], but answers the question
correctly. Moreover, he gives correct answers to
many other questions to which he didn't think he
knew the answer”, so it's not a lucky guess.
(Ichikawa and Steup, 2012).
3. The JTB account of knowledge
The conditions: Belief
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One way of responding to Radford's case is to
say that the suggestion is mistaken, and that
Albert answering such questions correctly
indicates that he has tacit or non-occurrent
beliefs as to what the right answers are.
3. The JTB account of knowledge
The Conditions: Truth
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So knowledge requires belief, but not all
beliefs are knowledge.
Why think that truth is a necessary condition
for knowledge?
We couldn't say that S knows that p if it's false
that p.
3. The JTB account of knowledge
The Conditions: Truth
The conception of truth drawn on is one
according to which there is a mind independent
reality.
So generally my thinking or wanting p to be the
case has no bearing on p being the case.
3. The JTB account of knowledge
The Conditions: Justification
As merely having a belief doesn't seem sufficient
for knowledge, neither does merely have a true
belief.
Sometimes someone gets something right, but
just because they get something right, it
needn't be that they know.
3. The JTB account of knowledge
The Conditions: Justification
Example:
Suppose S believes red will come up in the next roulette spin, but
that S believes this because black has come up in the previous
five consecutive spins. Given what we know about
probabilities, and assuming there is no cheating, then what has
come up in previous spins provides no basis for believing what
will come up in a future spin.
S has a true belief but he doesn't know that red will come up in
the next spin.
3. The JTB account of knowledge
The Conditions: Justification
The thought is that in such a case the agent just happens to get it
right or is lucky to get it right, and that such cases aren't cases
of knowledge.
By saying a belief needs to justified if it is to be a candidate for
knowledge, we're saying that a belief must be formed in the
right way. (Having a “justified” belief needn't imply that the
belief is true).
4. Gettier cases
Suppose that John looks at a clock. The clock
has correctly told the time over a long period.
The clock indicates that it is 8 o'clock. It is in
fact 8 o'clock. John forms the justified true
belief that it's 8 o'clock. But now further
suppose that the clock stopped exactly 12
hours previous to John looking at it.
Does John know that it's a 8 o'clock? Intuitively,
no.
4. Gettier cases
Gettier cases are cases in which an agent has a
justified true belief but not knowledge. Consider
“The Sheep in a Field” case, another Gettier
case:
Using his reliable perceptual faculties, Roddy noninferentially forms a belief that there is a sheep in the
field before him. His belief is also true. Unbeknownst
to Roddy, however, the truth of his belief is
completely unconnected to the manner in which he
acquired this belief since the object he is looking at in
the field is not a sheep at all, but rather a sheepshaped object which is obscuring from view the real
sheep hidden behind. (Chisholm, 1977: 105).
4. Gettier cases
A feature of the cases described is that though
the agent's justified belief is off track, through
epistemic luck (more specifically, doxastic
luck), the agent's belief nevertheless turns out
to be true.
Knowledge seems to have an internal and an
external component that need to be linked in
the right way in order for the there to be
knowledge.
4. Gettier cases
We might think that the solution to the Gettier
case is to require a causal connection between
an agent's belief that p and her belief being
true.
For example, that S's belief that p is causally
connected to the truth of p.
4. Gettier cases
But now consider the “The Barn-Façade County
case”, another Gettier case:
Using his reliable perceptual faculties, Barney noninferentially forms a true belief that the object in front
of him is a barn. Barney is indeed looking at a barn.
Unbeknownst to Barney, however, he is in an
epistemically unfriendly environment when it comes to
making observations of this sort, since most objects
that look like barns in these parts are in fact barn
façades.
4. Gettier cases
There is the mentioned causal connection,
Barney is looking at a real barn, he's not like
Roddy who was only looking at a sheep
shaped object.
Yet the standard intuition among epistemologists
is this also is not a case of knowledge. The
way Barney formed his belief is such that he
could have easily been wrong.
5. Conclusion
The focus of epistemology is the study of
knowledge.
The problem of the criterion is a challenge to
providing an account of knowledge.
5. Conclusion
The JTB account of knowledge: Each of the
conditions appear to be necessary and jointly
sufficient.
The Gettier counterexamples show that this is
not so.