EPISTEMOLOGY
WHAT IS KNOWLEDGE?
• Acquaintance: knowing of (I know of Paris)
• Ability: knowing how (I know how to ride a bike)
• Propositional: knowing that (I know that Paris is the capital of France)
THE NATURE OF DEFINITION AND HOW KNOWLEDGE MIGHT BE ANALYSED AND
DEFINED
- Zagzebski: To de ne something we must break concepts down, this is because they have a
real essence or nature. Some things only have a de nition that we give to them (i.e. weeds), this
is a nominal essence. Zagzebski claims that we are searching for a real essence to knowledge,
yet perhaps there is only a nominal one!
According to Zagzebski, when de ning knowledge we must be careful not to:
1. Be Via Negative (de ne something by what it’s not)
2. Be Circular (de ne it by itself)
3. Be Obscure (making our de nitions more unclear than the term ‘knowledge’).
4. Be Ad Hoc (adapting it to a given situation).
Zagzebski claims that knowledge should be de ned in terms of its necessary and su cient
conditions.
THE TRIPARTITE VIEW: JUSTIFIED TRUE BELIEF
Proposition knowledge is de ned as justi ed true belief: S knows that p if and only if:
1. S is justi ed in believing that p
2. p is true and
3. S believes that p (individually necessary and jointly su cient conditions).
Issues with J:
• Can be replaced with R (reliable process), or V (Virtuous True Belief). Choosing R allows
animals and children to also be said to have knowledge.
Issues with T:
• Zagzebski claims that knowledge is cognitive contact with , to lose T is contradictory to
this. But, perhaps one could adopt a coherence theory of truth, yet clearly this also requires truth
in some sense.
Issues with B:
• It seems you may be able to have knowledge without belief (remembering the words to a
song only when it is played), but really this appears not to be talking about propositional
knowledge.
ISSUES WITH THE TRIPARTITE VIEW: GETTIER
SMITH AND JONES:
P1. Smith and Jones are applying for the same job
P2. Smith forms the belief that Jones will get the job (being told so) - J
P3. Smith forms the belief that Jones has ten coins in his pocket (seeing them) - J
P4. Smith forms the Belief that the person who will get the job has ten coins in his pocket
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, P5. Then it is revelled that Smith has got the job and he discovers that he has ten coins in
his pocket - T
C. We have Justi ed True Belief, yet this is not su cient for knowledge.
BROWN IN BARCELONA:
P1. Smith Believes that Jones owns a Ford car.
P2. His Justi cation for this is that Jones has always owned a Ford car.
P3. Smith thinks about Brown and has no idea of his location but then forms a Belief that
‘Jones owns a Ford car or Brown is in Barcelona’
P4. He does this on the grounds of his Justi cation that Jones owns a Ford car.
P5. It turns out that Jones sold his car, and that Brown is in Barcelona.
C. So, Smith has JTB but lacks knowledge.
RESPONSES TO GETTIER:
No False Lemmas (JTB+N): Claims that there is always a false lemma in Gettier cases, and that
we should adapt the de nition of knowledge to:
1. P is true
2. You believe p
3. Your belief in p is justi ed
4. You did not infer p from a false lemma.
Problem (Zagzebski):
P1. Dr Jones has good evidence to Believe that Smith has virus X
P2. The symptoms and the results show results consistent with virus X and no
other known virus - J
P3. But Smith’s symptoms and the results are actually the result of an unknown
virus Y
P4. But Smith has also just contracted virus X (but so recently that symptoms have
not yet shown)
P5. So Jones’ belief that Smith has virus X is True, and has adequate Justi cation.
P6. And Jones does not Know that Smith has virus X because the evidence she
has is only inferred from virus Y.
P7. So Jones has JTB+N but yet still no knowledge.
C. Therefore JTB+N is not a su cient de nition for knowledge.
Infallibilism: We should only accept beliefs to be true when they are infallible (you cannot doubt
them) - we can only be certain of analytic truths and direct experiences.
Descartes’ and ideas of certainty:
P1. No one can know what is false
P2. Therefore, if I know something, then I cannot be mistaken about something
P3. For justi cation to be secure, justi cation must guarantee truth
P4. Therefore, if I am justi ed in believing something, I can’t possibly be mistaken
C. Therefore, Infallibilism leads to knowledge.
Strengths: Avoids Gettier style objections.
Weaknesses: Limits knowledge hugely, seems counter-intuitive - seems to say what the limits of
knowledge should be, not what they are!
Reliabilism (RTB): Replaces justi cation with Reliable methods
1. Something is true
2. You believe that something
3. Your belief is produced by a reliable cognitive process (perception, memory, testimony).
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, Problem: These are not always correct (we could have an incorrect memory) and it fails to
resolve Gettier cases: Smith saw the coins, and believed the testimony of the boss. Zagzebski’s
example of the doctor also highlights this, as these are usually seen as reliable processes.
Strengths: The advantage of reliabilism is that it is less chauvinistic than JTB as it allows children
and animals to have knowledge, as they seem to have knowledge through processes, not reason
and evidence.
Virtue Epistemology (VTB): Replaces justi cation with a character who has gained su cient
excellence in achieving knowledge and when knowledge is arrived at as a result of these skills
1. P is true
2. You believe that p
3. Your belief is the result of you exercising your intellectual virtues.
Virtue Epistemology focus on character rather than a process: Knowledge is an act of intellectual
virtue so, in a way we can dispose of T and B as this act holistically incorporates all of the criteria.
Sosa (AAA): Knowledge requires three things: Accuracy (is the belief true?), Adroitness
(did you discover this truth using intellectual skills/virtues) and Aptness (is it because of the skills
you used that you know the belief is true?
Strength: Avoids cases of luckily true beliefs, and adds a responsibility to the knowledge.
Weaknesses: Restrictive and chauvinistic, strays from exploring what we mean when we say S
knows that P to looking at the conditions that led to be in place for a person to claim that S knows
that P. In a sense Virtue Epistemology is avoiding the issue of knowledge and looking at character.
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, THEORIES OF PERCEPTION
DIRECT REALISM
• Objects exist mind independently
• We perceive them without mediation
• These objects have properties
The Problem of Perceptual Variation:
• Berkeley’s Clouds
• Russel’s Table
1. Our perception of an object changes.
2. An object cannot be changing its colour continually.
3. A table cannot be brown and yellow simultaneously.
4. Objects cannot be exactly as we directly perceive the object, but the appearance of the object
to our minds.
5. Therefore, Direct Realism is false
Response: • To say that because objects sometimes appear di erently then we can
only indirectly perceive them is incorrect.
• We can perceive objects directly
• The object appears to be di erent because of the perspective of the
perceiver.
• Objects have intrinsic properties and relational properties (can be
understood in relationship to other things).
• Direct Realists argues that objects and their properties can be perceived
immediately but that some of the properties of the object will change.
The Problem of Illusion:
• Stick in water
1. Sometimes I assign a property to an object that it does no possess.
2. For example - a stick in water appears bent when in reality it is not.
3. Therefore, what we immediately perceive is not what is in the world.
4. Therefore Direct Realism is false.
Response: • We do not perceive a bent stick.
• We directly perceive a stick half-half-submerged in water which appears to
be bent.
• The optic properties of water are di erent to the optic properties of air.
• Direct Realists conclude that they can still directly perceive objects by
taking into account the properties involved in their perception.
The Problem of Hallucination:
• Macbeth’s Dagger
1. In a hallucination we perceive something such as an image/sound/smell.
2. We believe that this is caused by a real thing.
3. However, there is no object to which the image/sound/smell relates.
4. Therefore, what we perceive must be mental - sense-data.
5. Hallucinations can be ‘subjectively indistinguishable from veridical perceptions. This means
we cannot tell the di erence between real perceptions and hallucinations.
6. Therefore, we see/hear/smell the same thing whether it is real or not.
7. Therefore, in all cases, we perceive sense-data, and not physical objects, directly.
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