Epistemology
Epistemology is the philosophical field in which one
studies knowledge, understanding, wisdom, justification,
the ethics of belief, and various domains of knowledge,
such as moral, modal, mathematical, self, and external
world knowledge.
At least one central point of departure in epistemology is
the the general human condition question: what is the
extent of human knowledge? What is it that we can know?
The human condition question is related to the issues of
what we do know and whether we can know at all.
Two Kinds of Knowledge
 Knowing How: ability-knowledge
 John knows how to ride a bike.
 John knows how to bake a cake.
 Knowing That: propositional knowledge
 John knows that 2 + 2 = 4.
 John knows that fire engines are red.
Question: Can all knowledge of one kind be reduced to
knowledge of the other kind?
Skepticism
Epistemological skepticism in it’s classical form is the
position that humans in fact know nothing, and cannot
know anything.
Skepticism is grounded at least partly on the view that one can argue
against a putative claim to know by showing that no one ever satisfies
the conditions on knowledge. Where S is a knower, p a proposition,
and F a condition on knowing, the skeptic argues, generally that:
1. S knows that p, only if S satisfies F.
2. S does not satisfy F.
3. So, S does not know that p.
Conditions on Propositional Knowledge
 Analysis of propositional knowledge: what
conditions are individually necessary and jointly
sufficient for propositional knowledge.
 Assumption of decomposition: propositional
knowledge is a complex relation that admits of an
informative decomposition.
 Where S is a knower, and p is a proposition:
S knows that p if and only if ______________
Knowledge and Truth
 Question: Does knowledge of a proposition imply that
the proposition is true?
 Infalibilism: If S knows that p, then p is true.
 Falibilism: S knows that p, but it is possible that p is
false.
Why be an infalibilist?
 Semantic / Pragmatic Data:
1st person: I know that 2 + 2 = 4, but I could be wrong.
3rd person: Jane knows that Mark loves her, but she could
be wrong.
 Other mental states do the work:
1st person: I believe that 2 + 2 = 4, but I could be wrong.
3rd person: Jane believes that Mark loves her, but she could
be wrong.
Why be a fallabilist?
 Knowledge is about one’s epistemic position relative to
evidence, not relative to truth alone.
 To believe that p on the basis of evidence e is to be in a
weaker position with respect to p, then to know that p
on the basis of e.
 John’s believing that p on the basis of e is in general less
epistemically important than John’s knowing that p on the
basis of e.
 Both knowledge and belief are compatible with error
Knowledge and Belief
 Question: Does knowledge of a proposition p by S
imply that S believes p?
 Doxastic: If S knows that p, then S believes that p.
 Non-Doxastic: S knows that p, but it is possible that S
does not believe that p.
Why be Doxastic?
 Semantic / Pragmatic Data:
 John knows that 2 +2 = 4, but John does not believe
that 2 + 2 = 4.
 Knowledge is a complex mind to world relation.
Thus it requires an internal component, some mental
state, and an external world component. Belief appears
to be the appropriate internal state. Truth the
appropriate external condition.
Why be Non-doxastic?
 Your colleagues at work tell you that the bridge on the
way to work is closed. So, it is plausible that you know
that the bridge on the way to work is closed. But out of
habit the next day you simply drive your car on your
normal route to work. As you approach the bridge you,
say, “oh no, I forgot that the bridge is closed.”
 From your behavior it looks like you believe that the
bridge is open, but from what your colleagues told you
it appears that you know that the bridge is closed.
 So, knowledge does not imply belief.
Knowledge and Justification
 Question: Does S’s knowledge that p imply that S is
justified in believing that p?
 Justification: If S knows that p, then S is justified in
believing that p.
 Non-Justification: S knows that p, but it is possible
that S is not justified in believing that p.
Why Accept Justification?
 Anti-Luck Intuition: Knowledge is inconsistent with
luck.
 What does a guess have in common with a piece of
knowledge? The fact that both involve true beliefs.
What distinguishes knowledge from a guess, is the fact
that the knower is not lucky with respect to the truebelief.
 Justification could be the added element that turns true
belief into knowledge.
Why Reject Justification?
 Knowledge is inconsistent with luck.
 But, distinguishing knowledge from true-belief does
not require that one use justification as the
distinguishing feature.
 Justification is a loaded notion that is tied to other
epistemic ideas. It might be easier to eliminate the antiluck component of knowledge by avoiding appeal to
justification.
Two Kinds of Justification
 Internalism about justification is the view if S is
justified in believing that p, then S has access to the
basis of S’s justification.
 Externalism about justification is the view that it is
possible for S to be justified in believing that p, even
though S does not have access to the basis of S’s
justification.
Two Kinds of Internalism
 Actual Internalism: S is justified in believing that p,
then S actually has present the basis of S’s justification.
 Access Internalism: S is justified in believing that p,
then S has access by reflection to the basis of S’s
justification.
Internalism requires of justification that one be able to
provide a justification for their belief.
Knowledge and Self-Illumination
 Question: Does knowledge of a proposition p, by S
imply that S knows that S’ knows that p?
 Self-Illumination: If S knows that p, then S knows that
S knows that p.
 Non-Self-Illuminating: S knows that p, but it is
possible that S does not know that S knows that p.
Why Accept Self-Illumination?
 S knows that p = S has a true belief that p with justification
that is content wise accessible to the agent.
 Since S knows that p, and the content of S’s justification for
believing that p is content wise accessible, then S’s has
access to the elements that jointly provide him with
justification strong enough for having knowledge.
 So, S can deduce that S knows that S knows that P, from the
elements of S’s knowledge that p that provide him with
justification for believing that p, strong enough for
knowledge.
Why Reject Self-Illumination?
 Reliability considerations. It is possible for an
instrument to be reliable in measuring a feature of its
environment in virtue of its design without knowing
how it does measure the environmental feature.
Consider a thermometer.
 By analogy if knowing the world for us is like a
thermometer measuring its environment, then it is
possible that we know things about the world without
knowing we know them. That is because we satisfy the
conditions for reliably measuring the environment
without knowing we satisfy these conditions.
Connecting Justification with SelfIllumination
 Access internalism maintains, where externalism denies,
that a necessary condition on being justified is that S
have access to the basis of their justification.
 Question: Can one deduce from access internalism the
thesis of self-illumination?
 Does a commitment to externalism require a rejection
of self-illumination?
Knowledge as Justified True Belief
 Assumption: Knowledge is a complex kind.
 Tripartite Analysis:
S knows that P if and only if
p is true
Infallibilism
S believes that p
Doxasticism
S is justified in believing that p.
Justification
Against Sufficiency
Gettier Cases (aim) to show that S can have a justified true
belief that p, even though S does not know that p.
Gettier cases are investigated against two assumptions about the
nature of justification:
Fallibilism about Justification: S can be justified in believing that p
even though p is false.
Closure of Justification: If S is justified in believing that p, and q
follows from p deductively, and S is justified in believing that q
follows from p deductively, then S is justified in believing that q.
Gettier’s Deduction Case
Jones believes that: (p) Smith owns a Ford.
Jones deduces from (p) that
(q) Either Smith owns a Ford or Brown is in Barcelona.
However, Smith does not own a Ford, but Brown is in
Barcelona.
q follows from p by the rule of addition, p is a justified
false belief for Jones, but q is a justified true belief for
Jones, since one disjunct of q is true.
Question: Does Jones know that q?
Solving Gettier
 Fix justification to rule out Gettier cases.
 Add fourth condition to rule out Gettier cases.
 Drop assumption that knowledge is decomposable.
 Maintain that Gettier does not refute JTB analysis.
No False Lemmas
Gettier maintains that
(i) Justification is fallible
(ii) Justification is closed under justified deduction.
To eliminate the problem case we can add:
(i) Knowledge cannot be produced from a justified false
belief. One must have no false justified beliefs in their
pathway to knowledge. The chain must involve only
true beliefs.
Barn Façade County
 A Barn Façade is the front portion of a barn, with no back.
From a certain angle it looks just like a barn, from another
angle it is revealed to be a fake barn.
 Barn county, is a fictional county in which there is a road
leading through the county, by the side of the road there are
numerous barn-facades. From the angle at which one is
driving through the county, one cannot see that the fake
barns are fake.
 There is only one real barn in barn façade county, but from
the front it is indistinguishable from all the fake barns.
 In general, while driving through the county one would
form many false beliefs that there are barns in front of them.
Barn Façade County and Reliability
 Suppose you are driving through Barn façade county,
and you look at the one and only real barn, B, in the
area that is an actual barn.
 Assume that you know what a barn is, and that you
generally can identify barns from other objects, which
are not similar. You are reliable with respect to basic
discrimination.
 Are you justified in believing that B is a barn based on
your perception of the barn?
No False Lemmas and Barn Façade County
 Suppose: S has a justified true belief in believing that B
is a barn. Does S know that B is a barn?
 If one thinks that S has a justified true belief that B is a
barn, but S does not know that B is a barn, one can
argue that adding the no false lemma condition to the
JTB analysis is not sufficient to solve the problem.
 By analyzing the Gettier deduction case and the
perceptual Barn Façade case one can see that there are
at least two kinds of luck.
Anti-Luck
 Pathway luck: the process by which you form your
belief is reliable, but you start in the wrong place, and
end up in a place that gives you a true justified belief.
 Environmental luck: the process by which you form
your belief is reliable, and the place where you start is
good, however, something about the environment
undermines the reliability of your belief forming
process.
 Compare: your eye sight is good at judging shape in
normal conditions, but not so good when you are in a
room with mirrors that stretch objects. You don’t know
because something about the environment is off.
Knowledge and Relevant Alternatives
On the Relevant Alternatives Approach to Knowledge:
S knows that p, then S can rule out all relevant alternatives
to p.
For every proposition p there is a set R of relevant
alternatives to p, which are such that were any member of
R true, S would not know that p.
The relevant alternatives approach is a modification of the
view that S knows that p only if s can rule out all
alternatives to p.
Why Accept Relevant Alternatives (RA)?
One supposed key advantage of RA is that it provides a
mechanism for answering skeptical challenges based on
the idea that knowledge requires the elimination of doubt.
The RA theorist is in effect arguing that knowledge only
requires elimination of relevant doubts, not all doubts.
Some doubts are not relevant for making a knowledge
attribution. Knowledge is contextually relative to certain
doubts.
Knowledge is the ability to select the relevant competing
hypotheses to a scenario, and rule them out from being
actual.
Why Reject Relevant Alternatives (RA)?
 Is there a mechanism for identifying what the relevant
alternatives are for any given proposition?
 Does (RA) really present a valid response to skeptical
threats?
 Is (RA) coherent with the semantic and pragmatic
data?
 How does one motivate relevant alternatives for
knowledge?
Knowledge and Reliability
On the simple Reliabilist Account of Knowledge:
S knows that p if and only if
p is true
S believes that p
S’s belief that p is the product of a reliable cognitive
process.
Why Accept Reliability?
Reliability appears to matter. Having your belief be the
output of a reliable process appears to be important.
We don’t trust unreliable sources when making knowledge
claims, such as faulty thermometers.
We don’t trust unreliable sources of testimony, such as
known liars.
We look to reliability when making decisions.
We care about reliable processes.
Why Reject Reliability?
Reliability could plausibly be a necessary condition on
knowledge, but it does not seem to be sufficient.
Consider a broken thermometer.
Consider Barn Façade County.
Consider a person who can tell the time with 100%
accuracy, without knowing why he can tell the time with
100% accuracy.
What about the generality problem: how do we define the
appropriate level for capturing reliability?
Knowledge and Causation
On the simple Causal Account of Knowledge:
S knows that p if and only if
p is true
S believes that p
The fact that p causes S belief that p.
Why Accept Causation?
Causation makes sense because we want our justification
to trace back to the truth-maker of our belief.
What goes wrong in a Gettier deduction case is that the
truth-maker, that Brown is in Barcelona, makes true the
belief that either Smith owns a Ford or Brown is in
Barcelona, while the justification comes from Jones’
interactions with Smith.
Causation can block this, by requiring that justification for
Jones’s belief come from the truth-maker.
Why Reject Causation?
Causation appears to be a plausible necessary condition on
certain kinds of knowledge, but it appears to fail in the direction
of sufficiency.
Suppose you are sleeping and someone hits you over the head
with a baseball bat, and you wake up and the first thing you
think is: someone just hit me over the head with a baseball bat.
Do you know that you were hit over the head with a baseball
bat? Or do you just have good evidence from your beliefs about
what it would feel like to be hit over the head by a baseball bat.
The problem of abstract objects: if there are abstract objects
then we would know of them without causation, since they are
not spatially and temporally related to us.
Knowledge as Apt Belief
The AAA evaluation of goal directed action:
Consider an Archer’s, A’s Shot at a Target T.
Was A’s shot successful?
If it is successful, then A’s shot is accurate.
Did A’s shot manifest A’s skill?
If it manifests A’s skill, then A’s shot is adroit.
Putting the two together we get aptness
A’s shot is accurate because adroit.
Knowledge as Apt Belief
On the AAA account of Knowledge
S knows that P if and only if
S belief that P is accurate – true
S belief that P is adroit – produced skillfully
S belief that P is apt – S’s belief that P manifests S skill.
Knowledge as apt belief requires that there is a connection
between the truth of the belief and the skill of the believer
in forming the belief. Knowledge requires skill on the part
of the believer.
Why Accept Apt Belief ?
The Apt belief account solves the Gettier deduction case,
and cases that are due to pathway luck.
Jones’s doesn’t know that either Smith owns a Ford or
Brown is in Barcelona
Because: (a) Jones’s belief is accurate (true), but (b) Jones’s
belief is not adroit (not due to Jones’s skill).
Thus, Jones’s belief is not apt.
Why Reject Apt Belief ?
The Apt belief account does not appear to be able to solve
problems due to environmental luck.
In Barn façade county, Jones appears to have an accurate,
and adroit belief that there is a barn in front of him. He
has a competence for picking out barns, and correctly
forms a belief that the barn in front of him is real. The
belief is a function of his skill.
However, if one maintains that Jones does not know in the
Barn case, then the Apt belief view appears to give the
wrong result.
Pragmatic Encroachment
Pragmatic Encroachment is not an analysis of knowledge, but
it is a claim about what factors may be relevant to analyzing
knowledge.
The central claim is that: a difference in pragmatic
circumstances can constitute a difference in knowledge.
Historically, it was thought that S knows that p was immune to
factors pertaining to what was at stake practically.
For example, it would seem that my knowledge of what time it
is cannot change depending on whether something for me that
is important depends on me being at a certain location at a
certain time.
Pragmatic Encroachment
Low Stakes: Hannah and her wife Sarah are driving home
on Friday afternoon. They plan to stop at the bank on the
way home to deposit their paychecks. It is not important
that they do so, as they have no impending bills. But as
they drive past the bank, they notice that the lines inside
are very long, as they often are on Friday afternoons.
Realizing that it wasn’t very important that their paychecks
are deposited right away, Hannah says,
“I know the bank will be open tomorrow, since I was
there just two weeks ago on Saturday morning. So we
can deposit our paychecks tomorrow morning.”
Pragmatic Encroachment
High Stakes: Hannah and her wife Sarah are driving
home on Friday afternoon. They plan to stop at the bank
on the way home to deposit their paychecks. Since they
have an impending bill coming due, and very little in their
account, it is very important that they deposit their
paychecks by Saturday. Hannah notes that she was at the
bank two weeks before on a Saturday morning, when it
was open. But, as Sarah points out, banks do change their
hours. Hannah says,
“I guess you’re right. I don’t know that the bank will be
open tomorrow.”
Pragmatic Encroachment
Those in favor of Pragmatic Encroachment will argue that
in the low stakes case Hannah does know, but in the high
stakes case it is true that Hannah does not know. That is the
utterances in both cases are correct.
Those against Pragmatic Encroachment will argue either
that Hannah does not know in both cases, or Hannah does
know in both cases.
Virtue Theoretic Approaches
Traditional theories of knowledge and justification
typically analyze:
S knows that p and S is justified in believing that p
by looking on at the nature of knowledge and justification.
Virtue theoretic approaches by contrast say that the
primary object of epistemic evaluation is the knower, and
not the abstract state of knowing or being justified.
Primary justification attaches to dispositions of knowers,
specific acts of knowing inherit positive status through the
dispositions.
Modal Conditions on Knowledge
Modal conditions on knowledge, unlike non-modal
conditions on knowledge, attempt to characterize
knowledge in terms of counterfactual conditions.
Counterfactual conditions are specified as follows:
If it were the case that A, it would be the case that B.
If it were not the case that B, it would not be the case that
A.
It is crucial to modal theories that some account of the
semantics of counterfactual is provided.
Knowledge and Sensitivity
Sensitivity is a modal condition on knowledge expressed
through a counterfactual relation. The sensitivity is about
truth.
(S’s belief that p is sensitive) if and only if (were p false, S
would not believe that p).
John belief that the truck is red is sensitive if and only if
were the truck any color other than red, John would not
believe that the truck is red.
Sensitivity is about tracking the truth.
Why Accept Sensitivity
Sensitivity can eliminate some cases of luck.
Jones believes that (p): Smith owns a Ford.
Jones believes that (q): either Smith owns a Ford or Brown
is in Barcelona.
Assume that both p and q are false, given the nature of
Jones’s evidence he would still believe q, since his belief
that q is based on evidence which is insensitive to the
falsity of q.
Sensitivity or tracking is good because it can eliminate luck
due to non-tracking of the relevant facts.
Why Reject Sensitivity?
Although sensitivity is good for getting rid of some luck,
such as pathway luck, it is not good at getting rid of all
luck, such as environmental luck.
Consider Barn County. It is plausible that one’s belief that
there is a barn in front of them while looking at the one
true barn, is a justified true belief, without knowledge. Is
the belief in question sensitive.
Would one still have believed that B is at location L, were
there no actual barn? If so, then it is possible for there to
be sensitive belief without knowledge.
Knowledge and Safety
Safety is a modal condition on knowledge:
S’s belief that p is safe if and only if were S to believe that p, p
would not be false.
Another way to state it is:
S’s belief that p is safe if and only if in all possible worlds near
the actual world where S believes that p, p is not false.
Safety is about how easily a belief could have been false.
How we measure distance between possible worlds is crucial to
the issue of how safety as a modal condition works out.
Why Accept Safety?
Safety is good because knowledge is not lucky.
A belief that is lucky is one that could have been false
easily.
So requiring that knowledge be safe, can rule out some
cases of luck, cases where were things just a little different,
one would not have a true belief.
Why Reject Safety?
Safety appears to be a good necessary condition on
knowledge, but it appears to be a bad sufficient condition
on knowledge.
If S belief that p is safe, then S knows that p.
S belief that p is safe if and only if were S to believe that p,
then p would not be false.
So, if were S to believe that p, p would not be false, then S
knows that p.