Epistemology ( (listen); from Greek, Modern
ἐπιστήμη, epistēmē, meaning 'knowledge',
and λόγος, logos, meaning 'logical discourse')
is the branch of philosophy concerned with
the theory of knowledge.Epistemology is the
study of the nature of knowledge, justification,
and the rationality of belief. Much debate
in epistemology centers on four areas: (1)
the philosophical analysis of the nature of
knowledge and how it relates to such concepts
as truth, belief, and justification, (2) various
problems of skepticism, (3) the sources and
scope of knowledge and justified belief, and
(4) the criteria for knowledge and justification.
Epistemology addresses such questions as:
"What makes justified beliefs justified?",
"What does it mean to say that we know something?",
and fundamentally "How do we know that we
know?".
== The problem of skepticism ==
Skepticism questions whether knowledge is
possible at all. Skeptics argue that belief
in something does not justify whether or not
it is necessarily true. Characterizing knowledge
as strong or weak is dependent on a person's
viewpoint and their characterization of knowledge.
Much of our knowledge on epistemology is derived
from, in particular, rational and philosophical
skepticism. The evil demon skepticism described
by Descartes (previously known from Plato's
cave; with an updated version from sci-fi
literature describing it as the brain in a
vat) supposes that our sensors have been placed
under the control of some external power such
as a demon, mad scientist, etc. As such, everything
we see is a fake, and we can never know anything
about the 'real' world inhabited by the demon
or mad scientist. Even if these external powers
do not exist, we still must depend on only
the information provided by our senses and
can therefore make no definite statement about
anything beyond that information.
Skeptics oppose what they sometimes call dogmatic
foundationalism, which states that there must
be some basic positions that are self-justified
or beyond justification without reference
to others. (One example of such foundationalism
may be found in Spinoza's Ethics.) The skeptical
response to this can take several approaches.
First, claiming that "basic positions" must
exist amounts to the logical fallacy of argument
from ignorance combined with the slippery
slope.Among other arguments, skeptics used
Agrippa's trilemma, named after Agrippa the
Skeptic, to claim certain belief could be
achieved. Foundationalists have used the same
trilemma argument as justification for demanding
the validity of basic beliefs.
This skeptical approach is rarely taken to
its pyrrhonean extreme by most practitioners.
Several modifications have arisen over the
years, including the following [1]:
Fictionalism would not claim to have knowledge
but adheres to conclusions on some criterion
such as utility, aesthetics, or other personal
criteria without claiming that any conclusion
is actually "true".
Philosophical fideism (as opposed to religious
Fideism) would assert the truth of some propositions,
but does so without asserting certainty.
Some forms of pragmatism would accept utility
as a provisional guide to truth but not necessarily
a universal decision-maker.
There are two different categories of epistemological
skepticism, which can be referred to as "mitigated"
and "unmitigated" skepticism. The two forms
are contrasting but are still true forms of
skepticism. Mitigated skepticism does not
accept "strong" or "strict" knowledge claims
but does, however, approve specific weaker
ones. These weaker claims can be assigned
the title of "virtual knowledge", but only
to justified beliefs. Unmitigated skepticism
rejects both claims of virtual knowledge and
strong knowledge. Characterizing knowledge
as strong, weak, virtual or genuine can be
determined differently depending on a person's
viewpoint as well as their characterization
of knowledge.
== Defining knowledge ==
In mathematics, it is known that 2 + 2 = 4,
but there is also knowing how to add two numbers,
and knowing a person (e.g., knowing other
persons, or knowing oneself), place (e.g.,
one's hometown), thing (e.g., cars), or activity
(e.g., addition). Some philosophers think
there is an important distinction between
"knowing that" (know a concept), "knowing
how" (understand an operation), and "acquaintance-knowledge"
(know by relation), with epistemology being
primarily concerned with the first of these.While
these distinctions are not explicit in English,
they are defined explicitly in other languages
(N.B. some languages related to English have
been said to retain these verbs, e.g. Scots:
wit and ken). In French, Portuguese, Spanish,
German and Dutch 'to know (a person)' is translated
using connaître, conhecer, conocer and kennen
(both German and Dutch) respectively, whereas
'to know (how to do something)' is translated
using savoir, saber (both Portuguese and Spanish),
wissen, and weten. Modern Greek has the verbs
γνωρίζω (gnorízo) and ξέρω (kséro).
Italian has the verbs conoscere and sapere
and the nouns for 'knowledge' are conoscenza
and sapienza. German has the verbs wissen
and kennen; the former implies knowing a fact,
the latter knowing in the sense of being acquainted
with and having a working knowledge of; there
is also a noun derived from kennen, namely
Erkennen, which has been said to imply knowledge
in the form of recognition or acknowledgment.
The verb itself implies a process: you have
to go from one state to another, from a state
of "not-erkennen" to a state of true erkennen.
This verb seems the most appropriate in terms
of describing the "episteme" in one of the
modern European languages, hence the German
name "Erkenntnistheorie". The theoretical
interpretation and significance of these linguistic
issues remains controversial.
In his paper On Denoting and his later book
Problems of Philosophy Bertrand Russell stressed
the distinction between "knowledge by description"
and "knowledge by acquaintance". Gilbert Ryle
is also credited with stressing the distinction
between knowing how and knowing that in The
Concept of Mind. In Personal Knowledge, Michael
Polanyi argues for the epistemological relevance
of knowledge how and knowledge that; using
the example of the act of balance involved
in riding a bicycle, he suggests that the
theoretical knowledge of the physics involved
in maintaining a state of balance cannot substitute
for the practical knowledge of how to ride,
and that it is important to understand how
both are established and grounded. This position
is essentially Ryle's, who argued that a failure
to acknowledge the distinction between knowledge
that and knowledge how leads to infinite regress.
In recent times, epistemologists including
Sosa, Greco, Kvanvig, Zagzebski and Duncan
Pritchard have argued that epistemology should
evaluate people's "properties" (i.e., intellectual
virtues) and not just the properties of propositions
or of propositional mental attitudes.
=== Belief ===
In common speech, a "statement of belief"
is typically an expression of faith or trust
in a person, power or other entity—while
it includes such traditional views, epistemology
is also concerned with what we believe. This
includes 'the' truth, and everything else
we accept as 'true' for ourselves from a cognitive
point of view.
=== Truth ===
Whether someone's belief is true is not a
prerequisite for (its) belief. On the other
hand, if something is actually known, then
it categorically cannot be false. For example,
if a person believes that a bridge is safe
enough to support her, and attempts to cross
it, but the bridge then collapses under her
weight, it could be said that she believed
that the bridge was safe but that her belief
was mistaken. It would not be accurate to
say that she knew that the bridge was safe,
because plainly it was not. By contrast, if
the bridge actually supported her weight,
then the person might say that she had believed
the bridge was safe, whereas now, after proving
it to herself (by crossing it), she knows
it was safe.
Epistemologists argue over whether belief
is the proper truth-bearer. Some would rather
describe knowledge as a system of justified
true propositions, and others as a system
of justified true sentences. Plato, in his
Gorgias, argues that belief is the most commonly
invoked truth-bearer.
=== 
Justification ===
In the Theaetetus, Socrates considers a number
of theories as to what knowledge is, the last
being that knowledge is true belief "with
an account" (meaning explained or defined
in some way). According to the theory that
knowledge is justified true belief, to know
that a given proposition is true, one must
not only believe the relevant true proposition,
but also have a good reason for doing so.
One implication of this would be that no one
would gain knowledge just by believing something
that happened to be true. For example, an
ill person with no medical training, but with
a generally optimistic attitude, might believe
that he will recover from his illness quickly.
Nevertheless, even if this belief turned out
to be true, the patient would not have known
that he would get well since his belief lacked
justification.
The definition of knowledge as justified true
belief was widely accepted until the 1960s.
At this time, a paper written by the American
philosopher Edmund Gettier provoked major
widespread discussion. (See theories of justification
for other views on the idea.)
=== Gettier problem ===
Edmund Gettier is best known for a short paper
entitled 'Is Justified True Belief Knowledge?'
published in 1963, which called into question
the theory of knowledge that had been dominant
among philosophers for thousands of years.
This in turn called into question the actual
value of philosophy if such an obvious and
easy counterexample to a major theory could
exist without anyone noticing it for thousands
of years. In a few pages, Gettier argued that
there are situations in which one's belief
may be justified and true, yet fail to count
as knowledge. That is, Gettier contended that
while justified belief in a true proposition
is necessary for that proposition to be known,
it is not sufficient. As in the diagram, a
true proposition can be believed by an individual
(purple region) but still not fall within
the "knowledge" category (yellow region).
According to Gettier, there are certain circumstances
in which one does not have knowledge, even
when all of the above conditions are met.
Gettier proposed two thought experiments,
which have become known as Gettier cases,
as counterexamples to the classical account
of knowledge. One of the cases involves two
men, Smith and Jones, who are awaiting the
results of their applications for the same
job. Each man has ten coins in his pocket.
Smith has excellent reasons to believe that
Jones will get the job and, furthermore, knows
that Jones has ten coins in his pocket (he
recently counted them). From this Smith infers,
"The man who will get the job has ten coins
in his pocket." However, Smith is unaware
that he also has ten coins in his own pocket.
Furthermore, Smith, not Jones, is going to
get the job. While Smith has strong evidence
to believe that Jones will get the job, he
is wrong. Smith has a justified true belief
that the man who will get the job has ten
coins in his pocket; however, according to
Gettier, Smith does not know that the man
who will get the job has ten coins in his
pocket, because Smith's belief is "...true
by virtue of the number of coins in Jones's
pocket, while Smith does not know how many
coins are in Smith's pocket, and bases his
belief...on a count of the coins in Jones's
pocket, whom he falsely believes to be the
man who will get the job." (see p. 122.) These
cases fail to be knowledge because the subject's
belief is justified, but only happens to be
true by virtue of luck. In other words, he
made the correct choice (believing that the
man who will get the job has ten coins in
his pocket) for the wrong reasons. This example
is similar to those often given when discussing
belief and truth—wherein a person's belief
of what will happen can coincidentally be
correct without the actual knowledge to base
it on.
==== Responses to Gettier ====
The responses to Gettier have been varied.
Usually, they have involved substantial attempts
to provide a definition of knowledge different
from the classical one, either by recasting
knowledge as justified true belief with some
additional fourth condition, or proposing
a completely new set of conditions, disregarding
the classical ones entirely.
===== Infallibilism, indefeasibility =====
In one response to Gettier, the American philosopher
Richard Kirkham has argued that the only definition
of knowledge that could ever be immune to
all counterexamples is the infallibilist one.
To qualify as an item of knowledge, goes the
theory, a belief must not only be true and
justified, the justification of the belief
must necessitate its truth. In other words,
the justification for the belief must be infallible.
Yet another possible candidate for the fourth
condition of knowledge is indefeasibility.
Defeasibility theory maintains that there
should be no overriding or defeating truths
for the reasons that justify one's belief.
For example, suppose that person S believes
he saw Tom Grabit steal a book from the library
and uses this to justify the claim that Tom
Grabit stole a book from the library. A possible
defeater or overriding proposition for such
a claim could be a true proposition like,
"Tom Grabit's identical twin Sam is currently
in the same town as Tom." When no defeaters
of one's justification exist, a subject would
be epistemologically justified.
The Indian philosopher B. K. Matilal has drawn
on the Navya-Nyāya fallibilism tradition
to respond to the Gettier problem. Nyaya theory
distinguishes between know p and know that
one knows p—these are different events,
with different causal conditions. The second
level is a sort of implicit inference that
usually follows immediately the episode of
knowing p (knowledge simpliciter). The Gettier
case is examined by referring to a view of
Gangesha Upadhyaya (late 12th century), who
takes any true belief to be knowledge; thus
a true belief acquired through a wrong route
may just be regarded as knowledge simpliciter
on this view. The question of justification
arises only at the second level, when one
considers the knowledge-hood of the acquired
belief. Initially, there is lack of uncertainty,
so it becomes a true belief. But at the very
next moment, when the hearer is about to embark
upon the venture of knowing whether he knows
p, doubts may arise. "If, in
some Gettier-like cases, I am wrong in my
inference about the knowledge-hood of the
given occurrent belief (for the evidence may
be pseudo-evidence), then I am mistaken about
the truth of my belief – and this is in
accordance with Nyaya fallibilism: not all
knowledge-claims can be sustained."
===== 
Reliabilism =====
Reliabilism has been a significant line of
response to the Gettier problem among philosophers,
originating with work by Alvin Goldman in
the 1960s. According to reliabilism, a belief
is justified (or otherwise supported in such
a way as to count towards knowledge) only
if it is produced by processes that typically
yield a sufficiently high ratio of true to
false beliefs. In other words, this theory
states that a true belief counts as knowledge
only if it is produced by a reliable belief-forming
process. Examples of reliable processes include:
standard perceptual processes, remembering,
good reasoning, and introspection.Reliabilism
has been challenged by Gettier cases. Another
argument that challenges reliabilism, like
the Gettier cases (although it was not presented
in the same short article as the Gettier cases),
is the case of Henry and the barn façades.
In the thought experiment, a man, Henry, is
driving along and sees a number of buildings
that resemble barns. Based on his perception
of one of these, he concludes that he has
just seen barns. While he has seen one, and
the perception he based his belief that the
one he saw was of a real barn, all the other
barn-like buildings he saw were façades.
Theoretically, Henry does not know that he
has seen a barn, despite both his belief that
he has seen one being true and his belief
being formed on the basis of a reliable process
(i.e. his vision), since he only acquired
his true belief by accident.
===== Other responses =====
Robert Nozick has offered the following definition
of knowledge:
S knows that P if and only if:
P;
S believes that P;
if P were false, S would not believe that
P;
if P were true, S would believe that P.Nozick
argues that the third of these conditions
serves to address cases of the sort described
by Gettier. Nozick further claims this condition
addresses a case of the sort described by
D. M. Armstrong: A father believes his daughter
innocent of committing a particular crime,
both because of faith in his baby girl and
(now) because he has seen presented in the
courtroom a conclusive demonstration of his
daughter's innocence. His belief via the method
of the courtroom satisfies the four subjunctive
conditions, but his faith-based belief does
not. If his daughter were guilty, he would
still believe her innocent, on the basis of
faith in his daughter; this would violate
the third condition.
The British philosopher Simon Blackburn has
criticized this formulation by suggesting
that we do not want to accept as knowledge
beliefs, which, while they "track the truth"
(as Nozick's account requires), are not held
for appropriate reasons. He says that "we
do not want to award the title of knowing
something to someone who is only meeting the
conditions through a defect, flaw, or failure,
compared with someone else who is not meeting
the conditions." In addition to this, externalist
accounts of knowledge, such as Nozick's, are
often forced to reject closure in cases where
it is intuitively valid.
Timothy Williamson has advanced a theory of
knowledge according to which knowledge is
not justified true belief plus some extra
condition(s), but primary. In his book Knowledge
and its Limits, Williamson argues that the
concept of knowledge cannot be broken down
into a set of other concepts through analysis—instead,
it is sui generis. Thus, according to Williamson,
justification, truth, and belief are necessary
but not sufficient for knowledge.
Alvin Goldman writes in his "Causal Theory
of Knowing" that knowledge requires a causal
link between the truth of a proposition and
the belief in that proposition.
=== Externalism and internalism ===
A central debate about the nature of justification
is a debate between epistemological externalists
on the one hand, and epistemological internalists
on the other.
Externalists hold that factors deemed "external",
meaning outside of the psychological states
of those who gain knowledge, can be conditions
of justification. For example, an externalist
response to the Gettier problem is to say
that for a justified true belief to count
as knowledge, there must be a link or dependency
between the belief and the state of the external
world. Usually this is understood to be a
causal link. Such causation, to the extent
that it is "outside" the mind, would count
as an external, knowledge-yielding condition.
Internalists, on the other hand, assert that
all knowledge-yielding conditions are within
the psychological states of those who gain
knowledge.
Though unfamiliar with the internalist/externalist
debate himself, many point to René Descartes
as an early example of the internalist path
to justification. He wrote that, because the
only method by which we perceive the external
world is through our senses, and that, because
the senses are not infallible, we should not
consider our concept of knowledge infallible.
The only way to find anything that could be
described as "indubitably true", he advocates,
would be to see things "clearly and distinctly".
He argued that if there is an omnipotent,
good being who made the world, then it's reasonable
to believe that people are made with the ability
to know. However, this does not mean that
man's ability to know is perfect. God gave
man the ability to know but not omniscience.
Descartes said that man must use his capacities
for knowledge correctly and carefully through
methodological doubt.The dictum "Cogito ergo
sum" (I think, therefore I am) is also commonly
associated with Descartes' theory. In his
own methodological doubt—doubting everything
he previously knew so he could start from
a blank slate—the first thing that he could
not logically bring himself to doubt was his
own existence: "I do not exist" would be a
contradiction in terms. The act of saying
that one does not exist assumes that someone
must be making the statement in the first
place. Descartes could doubt his senses, his
body, and the world around him—but he could
not deny his own existence, because he was
able to doubt and must exist to manifest that
doubt. Even if some "evil genius" were deceiving
him, he would have to exist to be deceived.
This one sure point provided him with what
he called his Archimedean point, in order
to further develop his foundation for knowledge.
Simply put, Descartes' epistemological justification
depended on his indubitable belief in his
own existence and his clear and distinct knowledge
of God.
=== Value problem ===
We generally assume that knowledge is more
valuable than mere true belief. If so, what
is the explanation? A formulation of the value
problem in epistemology first occurs in Plato's
Meno. Socrates points out to Meno that a man
who knew the way to Larissa could lead others
there correctly. But so, too, could a man
who had true beliefs about how to get there,
even if he had not gone there or had any knowledge
of Larissa. Socrates says that it seems that
both knowledge and true opinion can guide
action. Meno then wonders why knowledge is
valued more than true belief and why knowledge
and true belief are different. Socrates responds
that knowledge is more valuable than mere
true belief because it is tethered or justified.
Justification, or working out the reason for
a true belief, locks down true belief.The
problem is to identify what (if anything)
makes knowledge more valuable than mere true
belief, or that makes knowledge more valuable
than a more minimal conjunction of its components,
such as justification, safety, sensitivity,
statistical likelihood, and anti-Gettier conditions,
on a particular analysis of knowledge that
conceives of knowledge as divided into components
(to which knowledge-first epistemological
theories, which posit knowledge as fundamental,
are notable exceptions). The value problem
reemerged in the philosophical literature
on epistemology in the twenty-first century
following the rise of virtue epistemology
in the 1980s, partly because of the obvious
link to the concept of value in ethics.The
value problem has been presented as an argument
against epistemic reliabilism by philosophers
including Linda Zagzebski, Wayne Riggs and
Richard Swinburne. Zagzebski analogizes the
value of knowledge to the value of espresso
produced by an espresso maker: "The liquid
in this cup is not improved by the fact that
it comes from a reliable espresso maker. If
the espresso tastes good, it makes no difference
if it comes from an unreliable machine." For
Zagzebski, the value of knowledge deflates
to the value of mere true belief. She assumes
that reliability in itself has no value or
disvalue, but Goldman and Olsson disagree.
They point out that Zagzebski's conclusion
rests on the assumption of veritism: all that
matters is the acquisition of true belief.
To the contrary, they argue that a reliable
process for acquiring a true belief adds value
to the mere true belief by making it more
likely that future beliefs of a similar kind
will be true. By analogy, having a reliable
espresso maker that produced a good cup of
espresso would be more valuable than having
an unreliable one that luckily produced a
good cup because the reliable one would more
likely produce good future cups compared to
the unreliable one.
The value problem is important to assessing
the adequacy of theories of knowledge that
conceive of knowledge as consisting of true
belief and other components. According to
Kvanvig, an adequate account of knowledge
should resist counterexamples and allow an
explanation of the value of knowledge over
mere true belief. Should a theory of knowledge
fail to do so, it would prove inadequate.One
of the more influential responses to the problem
is that knowledge is not particularly valuable
and is not what ought to be the main focus
of epistemology. Instead, epistemologists
ought to focus on other mental states, such
as understanding. Advocates of virtue epistemology
have argued that the value of knowledge comes
from an internal relationship between the
knower and the mental state of believing.
== Acquiring knowledge ==
=== 
A priori and a posteriori knowledge ===
The nature of this distinction has been disputed
by various philosophers; however, the terms
may be roughly defined as follows:
A priori knowledge is knowledge that is known
independently of experience (that is, it is
non-empirical, or arrived at beforehand, usually
by reason). It will henceforth be acquired
through anything that is independent from
experience.
A posteriori knowledge is knowledge that is
known by experience (that is, it is empirical,
or arrived at afterward).A priori knowledge
is a way of gaining knowledge without the
need of experience. In Bruce Russell's article
"A Priori Justification and Knowledge" he
says that it is "knowledge based on a priori
justification," (1) which relies on intuition
and the nature of these intuitions. A priori
knowledge is often contrasted with posteriori
knowledge, which is knowledge gained by experience.
A way to look at the difference between the
two is through an example. Bruce Russell gives
two propositions in which the reader decides
which one he believes more. Option A: All
crows are birds. Option B: All crows are black.
If you believe option A, then you are a priori
justified in believing it because you don't
have to see a crow to know it's a bird. If
you believe in option B, then you are posteriori
justified to believe it because you have seen
many crows therefore knowing they are black.
He goes on to say that it doesn't matter if
the statement is true or not, only that if
you believe in one or the other that matters.
The idea of a priori knowledge is that it
is based on intuition or rational insights.
Laurence BonJour says in his article "The
Structure of Empirical Knowledge", that a
"rational insight is an immediate, non-inferential
grasp, apprehension or 'seeing' that some
proposition is necessarily true." (3) Going
back to the crow example, by Laurence BonJour's
definition the reason you would believe in
option A is because you have an immediate
knowledge that a crow is a bird, without ever
experiencing one.
Evolutionary psychology takes a novel approach
to the problem. It says that there is an innate
predisposition for certain types of learning.
"Only small parts of the brain resemble a
tabula rasa; this is true even for human beings.
The remainder is more like an exposed negative
waiting to be dipped into a developer fluid".
=== Analytic–synthetic distinction ===
Immanuel Kant, in his Critique of Pure Reason,
drew a distinction between "analytic" and
"synthetic" propositions. He contended that
some propositions are such that we can know
they are true just by understanding their
meaning. For example, consider, "My father's
brother is my uncle." We can know it is true
solely by virtue of our understanding what
its terms mean. Philosophers call such propositions
analytic". Synthetic propositions, on the
other hand, have distinct subjects and predicates.
An example would be, "My father's brother
has black hair." Kant stated that all mathematical
and scientific statements are analytic priori
propositions because they are necessarily
true but our knowledge about the attributes
of the mathematical or physical subjects we
can only get by logical inference.
The American philosopher Willard Van Orman
Quine, in his Two Dogmas of Empiricism, famously
challenged the distinction, arguing that the
two have a blurry boundary. Some contemporary
philosophers have offered more sustainable
accounts of the distinction.
=== Science as knowledge acquisition ===
Science is viewed as a refined, formalized,
systematic, or institutionalized form of the
pursuit and acquisition of empirical knowledge.
As such, the philosophy of science may be
viewed variously as an application or foundation
of the philosophy of knowledge acquisition.
== Regress problem ==
The regress problem is the problem of providing
a complete logical foundation for human knowledge.
The traditional way of supporting a rational
argument is to appeal to other rational arguments,
typically using chains of reason and rules
of logic. A classic example that goes back
to Aristotle is deducing that Socrates is
mortal. We have a logical rule that says All
humans are mortal and an assertion that Socrates
is human and we deduce that Socrates is mortal.
In this example how do we know that Socrates
is human? Presumably we apply other rules
such as: All born from human females are human.
Which then leaves open the question how do
we know that all born from humans are human?
This is the regress problem: how can we eventually
terminate a logical argument with some statement(s)
that do not require further justification
but can still be considered rational and justified?
As John Pollock stated:
... to justify a belief one must appeal to
a further justified belief. This means that
one of two things can be the case. Either
there are some beliefs that we can be justified
for holding, without being able to justify
them on the basis of any other belief, or
else for each justified belief there is an
infinite regress of (potential) justification
[the nebula theory]. On this theory there
is no rock bottom of justification. Justification
just meanders in and out through our network
of beliefs, stopping nowhere.
The apparent impossibility of completing an
infinite chain of reasoning is thought by
some to support skepticism. It is also the
impetus for Descartes' famous dictum: I think,
therefore I am. Descartes was looking for
some logical statement that could be true
without appeal to other statements.
=== Response to the regress problem ===
Many epistemologists studying justification
have attempted to argue for various types
of chains of reasoning that can escape the
regress problem.
FoundationalismFoundationalists respond to
the regress problem by asserting that certain
"foundations" or "basic beliefs" support other
beliefs but do not themselves require justification
from other beliefs. These beliefs might be
justified because they are self-evident, infallible,
or derive from reliable cognitive mechanisms.
Perception, memory, and a priori intuition
are often considered possible examples of
basic beliefs.
The chief criticism of foundationalism is
that if a belief is not supported by other
beliefs, accepting it may be arbitrary or
unjustified.
CoherentismAnother response to the regress
problem is coherentism, which is the rejection
of the assumption that the regress proceeds
according to a pattern of linear justification.
To avoid the charge of circularity, coherentists
hold that an individual belief is justified
circularly by the way it fits together (coheres)
with the rest of the belief system of which
it is a part. This theory has the advantage
of avoiding the infinite regress without claiming
special, possibly arbitrary status for some
particular class of beliefs. Yet, since a
system can be coherent while also being wrong,
coherentists face the difficulty of ensuring
that the whole system corresponds to reality.
Additionally, most logicians agree that any
argument that is circular is trivially valid.
That is, to be illuminating, arguments must
be linear with conclusions that follow from
stated premises.
However, Warburton writes in 'Thinking from
A to Z', "Circular arguments are not invalid;
in other words, from a logical point of view
there is nothing intrinsically wrong with
them. However, they are, when viciously circular,
spectacularly uninformative. (Warburton 1996)."
FoundherentismA position known as foundherentism,
advanced by Susan Haack, is meant to unify
foundationalism and coherentism. One component
of this theory is what is called the "analogy
of the crossword puzzle." Whereas, for example,
infinitists regard the regress of reasons
as "shaped" like a single line, Susan Haack
has argued that it is more like a crossword
puzzle, with multiple lines mutually supporting
each other.
InfinitismAn alternative resolution to the
regress problem is known as "infinitism".
Infinitists take the infinite series to be
merely potential, in the sense that an individual
may have indefinitely many reasons available
to them, without having consciously thought
through all of these reasons when the need
arises. This position is motivated in part
by the desire to avoid what is seen as the
arbitrariness and circularity of its chief
competitors, foundationalism and coherentism.
== Etymology ==
The word epistemology is derived from the
ancient Greek epistēmē meaning "knowledge"
and the suffix -logy, meaning "logical discourse"
(derived from the Greek word logos meaning
"discourse"). It is analogue to the German
Wissenschaftslehre (literally, theory of science)
which was introduced by philosophers Johann
Fichte and Bernard Bolzano in the late 18th
century. The word first appeared in English
in 1847 as a translation of the German in
New York's Eclectic Magazine review of a philosophical
novel by German author Jean Paul:
The title of one of the principal works of
Fichte is ′Wissenschaftslehre,′ which,
after the analogy of technology ... we render
epistemology.
It was properly introduced in the philosophical
literature by Scottish philosopher J.F. Ferrier
in his Institutes of Metaphysics (1854):
This section of the science is properly termed
the Epistemology—the doctrine or theory
of knowing, just as ontology is the science
of being... It answers the general question,
‘What is knowing and the known?’—or
more shortly, ‘What is knowledge?’
French philosophers then gave the term épistémologie
a narrower meaning as philosophy of science.
E.g., Émile Meyerson opened his Identity
and Reality, written in 1908, with the remark
that the word 'is becoming current' as equivalent
to 'the philosophy of the sciences.'The idea
of epistemology predates the word. John Locke
describes his Essay Concerning Human Understanding
(1689) as an inquiry "into the original, certainty,
and extent of HUMAN KNOWLEDGE, together with
the grounds and degrees of BELIEF, OPINION,
and ASSENT".. According to Brett Warrent,
the character Epistemon in King James VI of
Scotland's Daemonologie (1591) "was meant
to be a personification of a philosophical
concept currently known as ‘’epistemology’:
the investigation into the differences of
a justified belief versus its opinion."
== 
Branches or schools of thought ==
=== 
Historical ===
The historical study of philosophical epistemology
is the historical study of efforts to gain
philosophical understanding or knowledge of
the nature and scope of human knowledge. Since
efforts to get that kind of understanding
have a history, the questions philosophical
epistemology asks today about human knowledge
are not necessarily the same as they once
were. But that does not mean that philosophical
epistemology is itself a historical subject,
or that it pursues only or even primarily
historical understanding.
=== Empiricism ===
In philosophy, empiricism is generally a theory
of knowledge focusing on the role of experience,
especially experience based on perceptual
observations by the senses. Certain forms
exempt disciplines such as mathematics and
logic from these requirements.There are many
variants of empiricism: positivism, realism
and common sense being among the most commonly
expounded. But central to all empiricist epistemologies
is the notion of the epistemologically privileged
status of sense data.
=== Idealism ===
Many idealists believe that knowledge is primarily
(at least in some areas) acquired by a priori
processes or is innate—for example, in the
form of concepts not derived from experience.
The relevant theoretical processes often go
by the name "intuition". The relevant theoretical
concepts may purportedly be part of the structure
of the human mind (as in Kant's theory of
transcendental idealism), or they may be said
to exist independently of the mind (as in
Plato's theory of Forms).
=== Rationalism ===
By contrast with empiricism and idealism,
which centres around the epistemologically
privileged status of sense data (empirical)
and the primacy of Reason (theoretical) respectively,
modern rationalism adds a third 'system of
thinking', (as Gaston Bachelard has termed
these areas) and holds that all three are
of equal importance: The empirical, the theoretical
and the abstract. For Bachelard, rationalism
makes equal reference to all three systems
of thinking.
=== Constructivism ===
Constructivism is a view in philosophy according
to which all "knowledge is a compilation of
human-made constructions", "not the neutral
discovery of an objective truth". Whereas
objectivism is concerned with the "object
of our knowledge", constructivism emphasizes
"how we construct knowledge". Constructivism
proposes new definitions for knowledge and
truth that form a new paradigm, based on inter-subjectivity
instead of the classical objectivity, and
on viability instead of truth. Piagetian constructivism,
however, believes in objectivity—constructs
can be validated through experimentation.
The constructivist point of view is pragmatic;
as Vico said: "The norm of the truth is to
have made it."
=== 
Pragmatism ===
Pragmatism is an empiricist epistemology formulated
by Charles Sanders Peirce, William James,
and John Dewey, which understands truth as
that which is practically applicable in the
world. Peirce formulates the maxim: 'Consider
what effects, that might conceivably have
practical bearings, we conceive the object
of our conception to have. Then, our conception
of these effects is the whole of our conception
of the object.' This suggests that we are
to analyse ideas and objects in the world
for their practical value. This is in contrast
to any correspondence theory of truth that
holds that what is true is what corresponds
to an external reality. William James suggests
that through a pragmatist epistemology 'Theories
thus become instruments, not answers to enigmas
in which we can rest.' A more contemporary
understanding of pragmatism was developed
by the philosopher Richard Rorty who proposed
that values were historically contingent and
dependent upon their utility within a given
historical period.
=== Naturalized epistemology ===
Closely related to Pragmatism, naturalized
epistemology considers the evolutionary role
of knowledge for agents living and evolving
in the world. It de-emphasizes the questions
around justification and truth, and instead
asks, empirically, what beliefs should agents
hold in order to survive. It suggests a more
empirical approach to the subject as a whole—leaving
behind philosophical definitions and consistency
arguments, and instead using psychological
methods to study and understand how knowledge
actually forms and is used in the natural
world. As such it does not attempt to answer
the analytic questions of traditional epistemology
but replace them with new empirical ones.
=== Indian pramana ===
Indian philosophical schools such as the Hindu
Nyaya, and Carvaka, and later, the Jain and
Buddhist philosophical schools, developed
an epistemological tradition termed "pramana"
independently of the Western philosophical
tradition. Pramana can be translated as "instrument
of knowledge" and refers to various means
or sources of knowledge that Indian philosophers
held to be reliable. Each school of Indian
philosophy had their own theories about which
pramanas were valid means to knowledge and
which were unreliable (and why). A Vedic text,
Taittirīya Āraṇyaka (c. 9th–6th centuries
BCE), lists "four means of attaining correct
knowledge": smṛti ("tradition" or "scripture"),
pratyakṣa ("perception"), aitihya ("communication
by one who is expert", or "tradition), and
anumāna ("reasoning" or "inference").In the
Indian traditions, the most widely discussed
pramanas are: Pratyakṣa (perception), Anumāṇa
(inference), Upamāṇa (comparison and analogy),
Arthāpatti (postulation, derivation from
circumstances), Anupalabdi (non-perception,
negative/cognitive proof) and Śabda (word,
testimony of past or present reliable experts).
While the Nyaya school (beginning with the
Nyāya Sūtras of Gotama, between 6th-century
BCE and 2nd-century CE) were a proponent of
realism and supported four pramanas (perception,
inference, comparison/analogy and testimony),
the Buddhist epistemologists (Dignaga and
Dharmakirti) generally accepted only perception
and inference.
The theory of knowledge of the Buddha in the
early Buddhist texts has been interpreted
as a form of pragmatism as well as a form
of correspondence theory. Likewise, the Buddhist
philosopher Dharmakirti has been interpreted
both as holding a form of pragmatism or correspondence
theory for his view that what is true is what
has effective power (arthakriya). The Buddhist
Madhyamika school's theory of emptiness (shunyata)
meanwhile has been interpreted as a form of
philosophical skepticism.The main Jain contribution
to epistemology has been their theory of "many
sided-ness" or "multi-perspectivism" (Anekantavada),
which says that since the world is multifaceted,
any single viewpoint is limited (naya — a
partial standpoint). This has been interpreted
as a kind of pluralism or perspectivism. According
to Jain epistemology, none of the pramanas
gives absolute or perfect knowledge since
they are each limited points of view.
The Carvaka school of materialists only accepted
the pramana of perception and hence were one
of the first empiricists. There was also another
school of philosophical skepticism, the Ajñana.
=== Skepticism ===
Skepticism is a position that questions the
validity of some or all of human knowledge.
Skepticism does not refer to any one specific
school of philosophy, rather it is a thread
that runs through many philosophical discussions
of epistemology. The first well known Greek
skeptic was Socrates who claimed that his
only knowledge was that he knew nothing with
certainty. In Indian philosophy, Sanjaya Belatthiputta
was a famous skeptic and the Buddhist Madhyamika
school has been seen as taking up a form of
skepticism. Descartes' most famous inquiry
into mind and body also began as an exercise
in skepticism. Descartes began by questioning
the validity of all knowledge and looking
for some fact that was irrefutable. In so
doing, he came to his famous dictum: I think,
therefore I am.
Foundationalism and the other responses to
the regress problem are essentially defenses
against skepticism. Similarly, the pragmatism
of William James can be viewed as a coherentist
defense against skepticism. James discarded
conventional philosophical views of truth
and defined truth as based on how well a concept
works in a specific context, rather than objective
rational criteria. The philosophy of Logical
Positivism and the work of philosophers such
as Kuhn and Popper can be viewed as skepticism
applied to what can truly be considered scientific
knowledge.
== See also ==
== Notes
