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Epistemology, from the Greek words
episteme (knowledge) and logos (word/speech) is the branch
of philosophy that deals with the origin, nature and scope
of knowledge. Historically, it has been one of the most
investigated and most debated of all philosophical
subjects. Much of this debate has focused on analyzing the
nature and variety of knowledge and how it relates to
similar notions such as truth and belief. Much of this
discussion concerns the justification of knowledge claims.
Not surprisingly, the way that knowledge claims are
justified both leads to and depends on the general
approach to philosophy one adopts. Thus, philosophers have
developed a range of epistemological theories to accompany
their general philosophical positions. More recent studies
have re-written centuries-old assumptions, and the field
of epistemology continues to be vibrant and dynamic.
Defining knowledge
Justified true belief
In Plato's dialogue the Theaetetus, Socrates considers a
number of definitions of knowledge. One of the prominent
candidates is justified true belief. We know that, for
something to count as knowledge, it must be true, and be
believed to be true. Socrates argues that this is
insufficient; in addition one must have a reason or
justification for that belief.
One implication of this definition is that one cannot be
said to "know" something just because one believes it and
that belief subsequently turns out to be true. An ill
person with no medical training but a generally optimistic
attitude might believe that she will recover from her
illness quickly, but even if this belief turned out to be
true, on the Theaetetus account the patient did not know
that she would get well, because her belief lacked
justification.
Knowledge, therefore, is distinguished from true belief by
its justification, and much of epistemology is concerned
with how true beliefs might be properly justified. This is
sometimes referred to as the theory of justification.
The Theaetetus definition agrees with the common sense
notion that we can believe things without knowing them.
Whilst knowing p entails that p is true, believing in p
does not, since we can have false beliefs. It also implies
that we believe everything that we know. That is, the
things we know form a subset of the things we believe.
For most of philosophical history, "knowledge" was taken
to mean belief that was justified as true to an absolute
certainty. Any less justified beliefs were called mere
"probable opinion." This viewpoint still prevailed at
least as late as Bertrand Russell's early 20th century
book The Problems of Philosophy. In the decades that
followed, however, the notion that the belief had to be
justified to a certainty lost favour.
Gettier cases and contemporary definitions of knowledge
In the 1960s, Edmund Gettier argued that there are
situations in which a belief may be justified and true,
and yet would not count as knowledge - overturning in a
few short pages a theory that had been dominant for
thousands of years. Although being a justified, true
belief is necessary for a statement to count as knowledge,
it is not, Gettier demonstrated, sufficient. Gettier says
that formulations of the following form are flawed:
S knows that P if and only if:
This is because we can conceive of circumstances in which
a person might have a good reason to believe a general
proposition true, be correct, but not be correct for the
reasons which she takes herself to be. Gettier gives the
example of two persons, Smith and Jones who are awaiting
the results of their applications for the same job, both
of whom have ten coins in their pocket. Smith has
good reasons to believe that Jones will get the job
and is furthermore correct in his belief that Jones has
10 coins in his pocket (he saw them counted just a moment
before). However, Smith doesn’t know that he himself also
has 10 coins in his pocket. From this he infers that ‘a
person with ten coins in their pocked will get the job’.
In fact, Smith is to get the job – his reasons to believe
otherwise were excellent, but wrong. He satisfies all the
above conditions, but still we would be hesitant
to say that he knew what he thought he knew, because the
reasons he took to justify his belief, while strong, were
not the reasons which would have correctly justified his
belief. (Which might have included the knowledge of ‘I
have ten coins in my pocket’ and an overriding reason to
believe that he would get the job).
Someone might want to say that, in fact, as far as they
are concerned in the example given, Smith really does
‘know’ that ‘someone with ten coins in their pocket’ will
get the job, but many people find this hard to accept.
Responses to Gettier
Since Gettier's article, there have been an enormous number of articles trying to
provide an adequate definition of knowledge, several of
which have been an attempt to supply a further fourth
condition. Robert Nozick offers this formulation:
S knows that P if and only if:
P is true S believes that P If P were not true, S would not believe that P If P is true, S will believe that P |
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Simon Blackburn offers a critique of this formulation, in
which he suggests 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 another response to Gettier, Richard Kirkham has argued that the failures to find an account of
knowledge immune from counterexamples is because the only definition that could ever be immune to all
such counterexamples is the original one that prevailed from ancient times through Russell: to qualify
as an item of knowledge, a belief must not only be true and justified, the evidence for the belief must
necessitate its truth. Though this seems to set a very high hurdle for truth, Kirkham notes that it
doesn't exclude the possibility of rational belief altogether.
Some of the proposed solutions involve factors external to the agent. These responses are known as
theories of externalism. For example, one externalist response to the Gettier problem is to say that
the justified, true belief must be caused (in the right sort of way) by the relevant facts.
Contemporary approaches
Much contemporary work in epistemology depends on the two
categories: foundationalism and coherentism.
Recently, Susan Haack has attempted to fuse these two
approaches into her doctrine of Foundherentism, which
accrues degrees of relative confidence to beliefs by
mediating between the two approaches. She covers this in
her book Evidence and Inquiry: Towards Reconstruction in
Epistemology. Timothy Williamson, in his book Knowledge
and its Limits, seeks to revert the traditional
conceptual priority of belief to knowledge, instead
seeing belief as dependent on knowledge
Defining 'belief' in Epistemology
Knowledge is true and believed and ...Sometimes, when
people say they 'believe in' something, what they mean is
that they predict that it will prove to be useful or
successful in some sense - perhaps someone might 'believe
in' their favourite football team. This is not what
Epistemologists mean.
In the second sense of belief, to believe something just
means to think that it is true. That is, to believe P is
to do no more than to think, for whatever reason, that P
is the case. The reason is that in order to know
something, one must think that it is true - one must
believe (in the second sense) it to be the case.
Consider someone saying "I know that P, but I don't think
P is true". The person making this utterance has, in a
profound sense, contradicted themselves. If one knows
that P, then, amongst other things, one thinks that P is
indeed true. If one thinks that P is true, then one
believes P.
Knowledge is distinct from belief and opinion. If someone
claims to believe something, they are claiming that they
think that it is the truth. But of course, it might turn
out that they were mistaken, and that what they thought
was true was actually false. This is not the case with
knowledge. For example, suppose that Jeff thinks that a
particular bridge is safe, and attempts to cross it;
unfortunately the bridge collapses under his weight. We
might say that Jeff believed that the bridge was safe,
but that his belief was mistaken. We would not say that
he knew that the bridge was safe, because plainly it was
not. For something to count as knowledge, it must be
true.
Similarly, two people can believe things that are
mutually contradictory, but they cannot know
(unequivocally) things that are mutually contradictory.
For example, Jeff can believe the bridge safe, while
Jenny believes it unsafe. But Jeff cannot know the bridge
is safe and Jenny cannot know that the bridge is unsafe
simultaneously. Two people cannot know contradictory
things.
Distinguishing knowing that from knowing how
Suppose that Fred says to you: "The fastest swimming
stroke is the front crawl. One performs the front crawl
by oscillating the legs at the hip, and moving the arms
in an approximately circular motion". Here, Fred has
propositional knowledge of swimming and how to perform
the front crawl.
However, if Fred acquired this propositional knowledge
from an encyclopedia, he will not have acquired the skill
of swimming: he has some propositional knowledge, but
does not have any procedural knowledge or "know-how". In
general, one can demonstrate know-how by performing the
task in question, but it is harder to demonstrate
propositional knowledge. Michael Polanyi popularized the
term tacit knowledge to distinguish the ability to do
something from the ability to describe how to do
something. Gilbert Ryle had previously made a similar
point in discussing the characteristics of intelligence.
His ideas are summed up in the aphorism "efficient
practice precedes the theory of it". Someone with the
ability to perform the appropriate moves is said to be
able to swim, even if that person cannot precisely
identify what it is they do in order to swim. This
distinction is often traced back to Plato, who used the
term techne or skill for knowledge how, and the term
episteme for a more robust kind of knowledge in which
claims can be true or false.
A priori versus a posteriori knowledge: Western philosophers for centuries have distinguished
between two kinds of knowledge: a priori and a posteriori knowledge.
A priori knowledge is knowledge gained or
justified by reason alone, without the direct or indirect influence of any particular experience
(here, experience usually means observation of the world through sense perception. A posteriori knowledge is any other sort of
knowledge; that is, knowledge the attainment or justification of which requires reference to
experience. This is also called empirical knowledge.
One of the fundamental questions in epistemology is
whether there is any non-trivial a priori knowledge.
Generally speaking rationalists believe that there is,
while empiricists believe that all knowledge is
ultimately derived from some kind of external experience.
The fields of knowledge most often suggested as having a
priori status are logic and mathematics, which deal
primarily with abstract, formal objects.
Empiricists have traditionally denied that even these
fields could be a priori knowledge. Two common arguments
are that these sorts of knowledge can only be derived
from experience, and that they do not constitute "real" knowledge.
Justification:
Much of epistemology has been concerned with seeking ways to justify beliefs.
Irrationalism:
Some approaches to justifying beliefs are not rational —
that is, they reject the notion that justification must
obey logic or reason. Nihilism started out as a
materialistic political philosophy, but is sometimes
redefined as the apparently absurd doctrine that there
can be no justification for any claim — absurd because
the doctrine implies that nihilism itself cannot be
justified.
One definition of contemporary Mysticism is the use of
non-rational methods to arrive at beliefs and the
acceptance of such beliefs as knowledge. For example,
believing that something is true based on emotion may be
regarded as epistemological mysticism. An instance of
this may be when one bases one's belief in the existence
of something merely on one's desire that it should exist.
Another example might be the use of a daisy's petals and
the phrase "he loves me / he loves me not" while they are
plucked to determine whether Romeo returns Juliet's
affections. The mysticism in this example would be the
assumption that such a method has predictive or
indicative powers without rational evidence of this (this
does not necessarily lessen its importance as a symbolic
tool in human thought). In both of these examples, belief
is not justified through rational means. Mysticism need
not be an intentional process: one may engage in mystical
thought without realizing it. However, contemporary
Mysticism should not be confused with traditional
Mysticism, which is a spiritual practice in many Eastern
religions. It is the practice of focusing thought that is
important to traditional mysticism, rather than the
content of the thought.
Rationality:
Philosophical skeptics maintain that much of what we
typically take to be knowledge is not in fact knowledge.
In contrast to mystics, most skeptics attempt to present
logical arguments for their claims.
For instance, the regress argument has it that one can
ask for the justification for any belief. If that
justification depends on another belief, one can also
reasonably ask for the latter belief to be justified, and
so forth. This appears to lead to an infinite regress,
with each belief justified by some further belief. The
apparent impossibility of completing an infinite chain of
reasoning is thought by some to support skepticism.
Some philosophers, notably Peter Klein, have argued that
it is not impossible to have an infinite series of
reasons and that such an infinite series could explain
how we have knowledge. This position is known as
infinitism. Infinitists typically take the infinite
series to be merely potential, in the sense that an
individual may have indefinitely many reasons available
to him, without having consciously thought through all of
these reasons. The individual need only have the ability
to bring forth the relevant reasons when the need arises.
This position is motivated in part by the desire to avoid
skepticism.
Foundationalists respond to the regress argument by
claiming that some beliefs that are fit to support other
beliefs and knowledge do not themselves require
justification. Sometimes these foundational beliefs are
characterized as beliefs about what one is directly aware
of, or as beliefs that are self-justifying, or as beliefs
that are infallible. According to one particularly
permissive form of foundationalism, a belief may count as
foundational, in the sense that it may be presumed true
until defeating evidence appears, as long as the belief
appears to the subject to be true.
Another response to the regress problem is to reject the
assumption that beliefs can only be justified by linear
chains of reasoning. Coherentism holds that an individual
belief is justified not by such linear reasoning but by
the way the belief fits together (coheres) with the rest
of one's belief system. This has the advantage of
avoiding the infinite regress without claiming special
status for some particular class of beliefs. But since a
system can be coherent and yet still be wrong,
coherentists face the difficulty of ensuring that the
whole system corresponds in some way with reality.
Synthetic and analytic statements
Some statements are such that they appear not to need any
justification once one understands their meaning. For
example, consider: my father's brother is my uncle. This
statement is true in virtue of the meaning of the terms
it contains, and so it seems frivolous to ask for a
justification for saying it is true. Philosophers call
such statements analytic. More technically, a statement
is analytic if the concept in the predicate is included
in the concept in the subject. In the example, the
concept of uncle (the predicate) is included in the
concept of being my father's brother (the subject). Not
all analytic statements are as trivial as this example.
Mathematical statements are often taken to be analytic.
Synthetic statements, on the other hand, have distinct
subjects and predicates. An example would be my father's
brother is overweight.
Although anticipated by David Hume, this distinction was
more clearly formulated by Immanuel Kant, and later given
a more formal shape by Frege. Wittgenstein noted in the
Tractatus that analytic statements "express no thoughts",
that is, that they tell us nothing new; although analytic
statements do not require justification, they are
singularly uninformative. W.V.O. Quine, in his famous Two
Dogmas of Empiricism, challenged the legitimacy of the
analytic-synthetic distinction altogether.
Epistemological theories
It is common for epistemological theories to avoid
skepticism by adopting a foundationalist approach. To do
this, they argue that certain types of statements have a
special epistemological status — that of not needing to
be justified. So it is possible to classify
epistemological theories according to the type of
statement that each argues has this special status.
Empiricism
Empiricists claim knowledge is a product of human experience. Statements of observations take pride of
place in empiricist theory. Naïve empiricism holds simply that our ideas and theories need to be tested
against reality, and accepted or rejected on the basis of how well they correspond to observed facts.
The central problem for epistemology then becomes explaining this correspondence.
Empiricism is associated with science. While there can be little doubt about the effectiveness of
science, there is much philosophical debate about how and why science works. The Scientific Method
was once favored as the reason for scientific success, but recent difficulties in the philosophy of
science have led to a rise in coherentism. Empiricism is sometimes associated with a tradition
called logical empiricism, or positivism, which places higher emphasis on ideas about reality rather
than on experiences of reality.
Idealism
Idealism holds that what we refer to and perceive as the
external world is in some way an artifice of the mind.
Analytic statements (for example, mathematical truths),
are held to be true without reference to the external
world, and these are taken to be exemplary knowledge
statements. George Berkeley, Immanuel Kant and Georg
Hegel held various idealist views. Idealism is itself a
metaphysical thesis, but has important epistemological
consequences.
Naïve realism
Naïve realism, sometimes called Common Sense realism, is
the belief that there is a real external world, and that
our perceptions are caused directly by that world. It has
its foundation in causation in that an object being there
causes us to see it. Thus, it follows, the world remains
as it is when it is perceived - when it is not being
perceived - a room is still there once we exit. The
opposite theory to this is solipsism. Naïve realism fails
to take into account the psychology of perception.
Phenomenalism
Phenomenalism is a development from George Berkeley's
claim that to be is to be perceived. According to
phenomenalism, when you see a tree, you see a certain
perception of a brown shape, when you touch it, you get a
perception of pressure against your palm. On this view,
one shouldn't think of objects as distinct substances,
which interact with our senses so that we may perceive
them; rather we should conclude that all that really
exists is the perception itself.
Pragmatism
Pragmatism about knowledge holds that what is important
about knowledge is that it solves certain problems that
are constrained both by the world and by human purposes.
The place of knowledge in human activity is to resolve
the problems that arise in conflicts between belief and
action. Pragmatists are also typically committed to the
use of the experimental method in all forms of inquiry, a
non-skeptical fallibilism about our current store of
knowledge, and the importance of knowledge proving itself
through future testing.
Rationalism
Rationalists believe that there are a priori or innate ideas that are not derived from sense experience.
These ideas, however, may be justified by experience. These ideas may in some way derive from the structure
of the human mind, or they may exist independently of the mind. If they exist independently, they may be
understood by a human mind once it reaches a necessary degree of sophistication.
The epitome of the rationalist view is Descartes' Cogito ergo sum ("I think, therefore I am"), in which
the skeptic is invited to consider that the mere fact that he doubts this claim implies that there is a
doubter. Because doubting is a kind of thinking, the claim must be correct. Spinoza derived a rationalist
system in which there is only one substance, God. Leibniz derived a system in which there are an infinite
number of substances, his Monads.
Representationalism
Representationalism or representative realism, unlike
naïve realism, proposes that we cannot see the external
world directly, but only through our perceptual
representations of it. In other words, the objects and
the world that you see around you are not the world
itself, but merely an internal virtual-reality replica of
that world. The so-called veil of perception removes the
real world from our direct inspection.
Relativism
Relativism as advocated by Protagoras maintains that all
things are true and in a constant state of flux,
revealing certain aspects of truth at one time while
concealing them at another. It claims that there is no
objective truth: anything which a person can perceive is
true for that person, but not necessarily true for the
next person. By equating perceptions and beliefs with
truth, overt self-contradiction is avoided.
Skepticism
When scientists or philosophers ask "Is knowledge
possible?", they mean to say "Am I ever sufficiently
justified in believing something in order to have
knowledge?" Adherents of philosophical skepticism often
say "no". Philosophical skepticism is the position which
critically examines whether the knowledge and perceptions
people have are true; adherents of this position hold
that one can never obtain true knowledge, since
justification is never certain. This is a different
position from scientific skepticism, which is the
practical stance that one should not accept the veracity
of claims until solid evidence is produced.
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