Epistemology

Epistemology or the theory of knowledge is the branch of philosophy that studies the nature and scope of knowledge. The term "epistemology" originated from the Greek words episteme (knowledge) and logos (account/explanation). The term is thought to have been coined by James Frederick Ferrier.

Much of the debate in this field has focused on analyzing the nature of knowledge and how it relates to similar notions such as truth, and belief. Much of this discussion concerns justification. Epistemologists analyze the standards of justification for knowledge claims, that is, the grounds on which one can claim to know a particular fact. In a nutshell, epistemology addresses the questions, "Do you really know what you think you know?" and, if so, "How do you know what you know?"

There are different approaches to the theory of knowledge. Recent studies have re-written centuries-old assumptions, and so, the field of epistemology continues to be vibrant and dynamic.

Defining knowledge

Justified true belief

In Plato's dialogue the Theaetetus (Theætetus), Socrates considers a number of definitions of knowledge. One prominent candidate is justified true belief. For something to count as knowledge, it must be true and be believed to be true (see section on defining belief in Epistemology, below). Socrates argues this is insufficient. One must also have a reason or justification for that belief.

One implication of this is one cannot be said to "know" something just because one believes something that 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. 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 accords 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," (also known as provisional knowledge.) 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. Fallibilism is the view that knowledge is not the same as certainty, nor implies certainty. One important reason fallibilism has become nearly the standard view is that science has been recognized as providing knowledge, but not certainty, since science is empirical and based on sense-perception, and so is fallible. So one can choose either fallibilism or the incalcuably improbable doctrine that there is no scientific knowledge. Another reason is that the view that knowledge must be certain seems to involve a confusion between the truth that necessarily, if proposition, p is known, then proposition p is true, with the falsity that if proposition p is known, then proposition p is necessarily true. [Involved here too is the modal fallacy of "pushing" the necessity operator through parentheses: thus, (N)(Kp->p) does not entail Kp -> (N)p]

Gettier cases and contemporary definitions of knowledge

Main article: Gettier problem

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:

• p;
• S believes that p; and
• S is justified in believing that p.

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 pockets. Smith has excellent reasons to believe that Jones will get the job and is furthermore correct in his belief that Jones has ten coins in his pocket (he saw them counted just a moment before). From this he infers that ‘a person with ten coins in his pocket will get the job’. However, Smith doesn’t know that he himself also has ten coins in his pocket. In fact, Smith is to get the job – his reasons to believe otherwise were excellent, but wrong. His belief that ‘a person with ten coins in his pocket will get the job’ 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

Gettier's article was published in 1963. Since then, 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.
• S believes that p.
• if p were false, S would not believe that p.
• if p is true, S will believe that p.

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 can be attributed to the fact that the only definition of knowledge that could ever be immune to all such counterexamples is the one that prevailed from ancient times up to 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. While this seems to set a very high standard for knowledge, 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.

Yet another possible candidate for the fourth condition of knowledge is that one's justification be undefeated. Defeasibility theory maintains that there be no overriding or defeating truths of the reasons that justify one's belief. For example, let's suppose that person S believes they 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.' So long as no defeaters of one's justification exist, a subject is epistemically justified.

Contemporary approaches

Much contemporary work in epistemology depends on 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 over 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' his or her favorite 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 that P is true". The person making this utterance has, in a profound sense, contradicted himself. If one knows P, then, among other things, one thinks that P is indeed true. If one thinks that P is true, then one believes P. (See: Moore's paradox.)

Knowledge is distinct from belief and opinion. If someone claims to believe something, he is claiming that he thinks that it is the truth. But of course, it might turn out that he was mistaken, and that what he 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 is 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 popularised 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 he does in order to swim. This distinction is often traced back to Plato, who used the term techne or skill for know-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. See Rationalism, below, for clarification.)
• A posteriori knowledge is any other sort of knowledge; that is, knowledge the attainment or justification of which invovles 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 non trivial knowledge is ultimately derived from some kind of external experience.

The a priori / a posteriori distinction is often thought to map onto the distinction between synthetic and analytic propositions. Doubt was cast onto the latter distinction by the American philosopher W.V.O Quine, and it is now commonly recognised that the two distinctions are not co-extentional.

Justification

Much of epistemology has been concerned with seeking ways to justify beliefs.

Chains of reasoning

Philosophical skeptics maintain that much (or all) of what we typically take to be knowable, is in fact not. Historically, the Pyrrhonian skeptics went so far as to doubt the results of reasoning and justification. Unfortunately, these skeptics presented logical arguments for their claims.

For instance, the skeptic may employ the regress argument which consists in asking 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. The skeptic will argue that since no one knows if the infinite chain ends in support of knowledge or ignorance, that it's then more reasonable to withhold judgment about that reasoning and justification. However, many epistemologists studying justification have attempted to argue for various types of chains of reasoning that can escape the infinite regress.

Some philosophers, notably Peter Klein, have argued that it's not impossible to have an infinite series of reasons, and that such an infinite series could still 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. It may avoid skepticism because the reasons will eventually hit the required amount for knowledge.

Foundationalists, on the other hand, respond to the regress argument by claiming that some beliefs that are fit to support other beliefs for knowledge do not themselves require a 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. Others have argued that a belief is justified if it's a 'basic belief' rooted in perception or a prori knowledge and needing no other additional justifying reason.

Another response to the regress problem is to reject the assumption that beliefs can only be justified by linear chains of reasoning. For the coherentist, there is a serious motive behind rejecting linear justification. Traditionally, a coherentist chain of reasoning worked, linearly, in a circle. Obviously, this is a dangerous and fallacious chain of justification. However, most coherentists now hold 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. Yet, since a system can be coherent while also being wrong, coherentists face the difficulty in ensuring that the whole system corresponds to reality.

Synthetic and analytic statements

Main article: Analytic/synthetic distinction

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 said in the Tractatus that "The propositions of logic therefore say nothing. (They are the analytical propositions.)" That is, analytic statements tell us nothing new; although analytic statements do not require justification, they are singularly uninformative. In "Two Dogmas of Empiricism", philosopher W.V.O. Quine famously challenged the distinction between analytic and synthetic statements.

The Lottery Paradox

One major problem for epistemologists studying justification is the Lottery Paradox. Originally noticed by H.E. Kyburg in his 1961 Probability and the Logic of Rational Belief, the Lottery Paradox seems to generate a vicious problem for many accounts of justification.

The paradox can be simply put. Let's imagine that one wishes to enter a local lottery along with thousands of other participants. However, it's immediately recognizable that the chance of one's ticket losing is so high that one is justified in believing that it won't win. Probability seems to confirm the justification for such a belief. Yet, it's not just one's individually purchased ticket that has such a high probability of losing, but any ticket that's been bought in a fair lottery. Furthermore, since one seems justfied in believing that each individual ticket won't win, one also seems justified in believing that the conjunction of all tickets, or that every ticket won't win. On the other hand, one must also remember that in all lotteries there's the slight probability that a ticket will win. After all, there's always one winner. Following this, one doesn't seem justified in believing that the conjunction of all tickets, or every ticket, won't win. Therefore, one is paradoxically justified in believing that every ticket won't win, and also not justified in believing that every ticket won't win.

If the paradox had to be put in a few premises, as it was in Peter Klein's Certainty, it would look like this:

Premise 1: There's probabilistic evidence that one is justified in believing that ticket 1 will lose, and justified in believing ticket 2 will lose ... and justified in believing ticket n will lose.

Premise 2: If one is justified in believing that ticket 1 will lose, and justified in believing ticket 2 will lose ... and justified in believing ticket n will lose, then one is justified in believing that ticket 1, and ticket 2 ... and ticket n will lose..

Premise 3: There's probabilistic evidence that one is not justified in believing that ticket 1, and ticket 2 ... and ticket n will lose.

------

Conclusion: Therefore, one is justified in believing that ticket 1, and ticket 2 ... and ticket n will lose and not justified in believing that ticket 1, and ticket 2 ... and ticket n will lose.

The Lottery Paradox was also construed slightly differently in David Lewis' "Elusive Knowledge." Let's imagine that one knows how many thousands or millions of tickets there are, and one also knows the number of losing tickets as well as the number of winning tickets, one. Under his interpretation, there are so many tickets and possibilities of losing that no matter how many tickets you know will lose, it's still not great enough to turn your justified belief into knowledge.

Epistemological theories

Empiricism

In philosophy generally, empiricism is a theory of knowledge emphasizing the role of experience. Experience may be understood to include all contents of consciousness or it may be restricted to the data of the senses only.

In the philosophy of science, empiricism is a theory of knowledge which emphasizes those aspects of scientific knowledge that are closely related to experience, especially as formed through deliberate experimental arrangements. It is a fundamental requirement of scientific method that all hypotheses and theories must be tested against observations of the natural world, rather than resting solely on a priori reasoning, intuition, or revelation. Hence, science is considered to be methodologically empirical in nature.

Idealism

Idealism holds that what we refer to and perceive as the external world is in some way an artifice of the mind. Objects that are the basis of these perceptions can only be known indirectly or mediately. 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. Some argue that naïve realism fails to take into account the psychology of perception, but naïve realists argue that viewing the psychology of perception as a problem for naïve realism requires begging the question in favor of idealism. (See: G.E. Moore.)

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 should not think of objects as distinct substances that we perceive with our senses. Rather, perception itself is all that really exists.

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 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.

Reliabilism

A theory purported by philosophers such as Alvin Goldman that epistemic justification is an external matter in the sense that a belief is justified only if it is produced by processes that will yield a sufficiently high ratio of true to false beliefs. This view is often contrasted with the views of epistemological internalists who typically hold that the justification of our beliefs depends entirely upon how a particular belief relates to other psychological states of the agent. Externalists now typically think that such relations are part of what is involved in the justification of belief. This is thanks in no small part to the influence of BonJour's examples in which he asks us to imagine someone who had the ability to reliably determine the location of the President using clairvoyance. It seems that even if we imagined such a subject, we would be hesitant to say that they were justified in believing (say) that the President was in New York even if we granted that the means by which they arrived at this belief were in fact reliable since they had no reason to assume that their means for establishing the President's location were reliable.

To get a sense of what the reliabilist view amounts to, imagine that there is someone who is caused to have just the same psychological states that you do not because they interact with an environment that is like yours but because a Cartesian demon delights in tricking them into thinking mistakenly that they are in an environment like yours. On simple versions of reliabilism, it seems we have to say that while you are justified in believing what you do, your psychological duplicate is not because the means by which they arrive at their judgments about their surroundings is not at all likely to be effective for determining how things really are in the external world. Some are bothered by this implication because they think that such outside interference may obscure the truth but cannot undermine your ability to reason as you should. The intuition that having a justified belief is simply a matter of forming beliefs by reasoning as you should given the inputs of experience, memory, and intuition is taken to support the internalist conception of justification.

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 or believe 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.

From this stems a paradox, felt by many to be fatal: If truth is relative, how is this relativism determined? Since objectivity does not exist, how can a perspective be deemed relative or otherwise?

Skepticism

Philosophical skepticism claims that no person ever knows that any proposition is true. By contrast, scientific skepticism is the practical stance that one should accept only those claims supported by sufficient evidence. Another form of skepticism, Pyrrhonism, does not deny that humans can possess knowledge, but holds there is not a better argument for humans either having or not having knowledge. Oddly, the Pyrrhonian also believes that one can know evident propositions. Epistemology and a human being's knowledge, on the other hand, is far from evident.

Contextualism

Contextualism in epistemology is quite different from relativism and contextualism in philosophy of language. The epistemological contextualist claims that knowledge varies with the context in which it is attributed. More precisely, contextualism is the claim that, in a sentence of the form "S knows that P", the relation between S and P depends on the context of discussion. According to the contextualist the term "knows" is context-sensitive in a way similar to terms such as "poor", "tall" and "flat". The motivation behind contextualism is the idea that, in the context of a discussion with an extreme skeptic about knowledge, there is a very high standard for the accurate ascription of the term "knowledge", while in ordinary usage, there is a lower standard. Hence, contextualists attempt to evade skeptical conclusions by maintaining that skeptical arguments against knowledge are not relevant to our ordinary usages of the term. Skeptics are using the word "knowledge" in the wrong context.

The contextualist strategy against the skeptic consists fundamentally in the denial of the skeptical paradoxes that arise from two competing intuitions: Most people accept the common sense, realist claim that they have hands, for example. At the same time, they feel compelled to assent to skeptical possibilties such as that proposed in the brain-in-a-vat thought experiment. However, these intuitions lead to a paradox under the principle of closure, which states that if one can deduce one thing which implies another, say S knows that P and P imples Q. Also, if S knows that P implies Q then S must also be in the position to know its implication, or Q. Yet, unfortunately, no one is ever in a position to know Q in various skeptical hypotheses. The acceptance of all of this leads to the following skeptical argument against knowledge:

If Jane knows that she has a hand, then Jane knows that she is not a brain in a vat.

Jane does not know that she is not a brain in a vat.

------

Jane does not know that she has a hand.

The contextualist suggests that this argument actually represents two different arguments depending on the context. In the context of discourse with a skeptic, where the standards for what may be considered knowledge are extremely high, the term "knows" and hence the entire argument means something different from what it means in a different, more ordinary context. In the high-standards context, the argument is both valid and sound. But in the ordinary context, the argument is unsound, because the second premise is not true.

Invariantism

There are actually several forms of invariantism in philosophy. For example, there are semantic theories of invariantism in philosophy of language. We shall focus on its use in epistemology, where invariantism is simply opposed to contextualism. Invariantists claim that the meaning of the term "knowledge" and hence the proposition expressed by the sentence "S knows that p" does not vary from context to context. Instead, there is one single epistemic standard that determines if the content of this sentence, "S knows that p," counts as knowledge. The high but reachable invariantist epistemic standard doesn't change, and thus other, looser forms of knowledge in other contexts simply can't be epistemic.

One hypothetical example of an invariantist standard may be to require a subject's propositions to have 100% probability. Such a standard could defeat skepticism because the skeptical requirement of ruling out any proposition contrary to P would then be superfluous. However, this assumes that skeptics can't define the invariantist standard itself, and that a "100% probability" requirement wouldn't be too weak a requirement for knowledge.

Correspondence

Another common theory of knowledge is that the content of the mind can often correspond to the reality outside of it. Depending on the question being investigated, statements and observations in one's mind can very accurately correspond to the actual world out there, around us, and within. However, some questions cannot be answered so easily, and the mind cannot correspond accurately to the reality outside of it. A human mind cannot fully comprehend all attributes of God, assuming that one can know for certain that God exists. A good example of true correspondence is any obvious empirical claim, such as the fact that the Rocky Mountains exist, because anyone can verify this claim and go to see them, and then have within their mind the images and statements that partially correspond to the actual mountain range that exists.

Falsificationism

Falsificationism holds that science proceeds in an evolutionary manner by conjectures and refutations. Theories are improved by increasing the degree of falsifiablity and knowledge grows by trying to refute them and replace them by better ones. It is casually dubbed the trial and error method of epistemology.

References and further reading

• Annis, David. 1978. "A Contextualist Theory of Epistemic Justification", in American Philosophical Quarterly, 15: 213-219.
• Boufoy-Bastick, Z. 2005. "Introducing 'Applicable Knowledge' as a Challenge to the Attainment of Absolute Knowledge", Sophia Journal of Philosophy, 8: 39-51. Online PDF.
• Bovens, Luc & Hartmann, Stephan. 20003. Bayesian Epistemology. Oxford: Oxford University Press.
• Butchvarov, Panayot. 1970. The Concept of Knowledge. Evanston, Northwestern University Press.
• Cohen, Stewart. 1998. "Contextualist Solutions to Epistemological Problems: Scepticism, Gettier, and the Lottery." Australasian Journal of Philosophy, 76: 289-306.
• Cohen Stewart. 1999. "Contextualism, Skepticism, and Reasons", in Tomberlin 1999.
• DeRose, Keith. 1992. "Contextualism and Knowledge Attributions", Philosophy and Phenomenological Research, 15: 213-19.
• DeRose, Keith. 1999. "Contextualism: An Explanation and Defense", in Greco and Sosa 1999.
• Feldman, Richard. 1999. "Contextualism and Skepticism", in Tomberlin 1999, pp. 91-114.
• Gettier, Edmund. 1963. "Is Justified True Belief Knowledge?", Analysis, Vol. 23, pp. 121-23. Online text.
• Greco, J. & Sosa, E. 1999. Blackwell Guide to Epistomology, Blackwell Publishing.
• Hawthorne, John. 2005. "The Case for Closure", Contemporary Debates in Epistemology, Peter Sosa and Matthias Steup (ed.): 26-43.
• Hendricks, Vincent F. 2006. Mainstream and Formal Epistemology, New York: Cambridge University Press.
• Keeton, Morris T. 1962. "Empiricism", in Dictionary of Philosophy, Dagobert D. Runes (ed.), Littlefield, Adams, and Company, Totowa, NJ, pp. 89–90.
• Kirkham, Richard. 1984. "Does the Gettier Problem Rest on a Mistake?" Mind, 93.
• Klein, Peter. 1981. Certainty: a Refutation of Scepticism, Minneapolis, MN: University of Minnesota Press.
• Kyburg, H.E. 1961. Probability and the Logic of Rational Belief, Middletown, CT: Wesleyan University Press.
• Lewis, David. ?. "Elusive Knowledge." Australian Journal of Philosophy, 74, 549-67.
• Rand, Ayn. 1979. Introduction to Objectivist Epistemology, New York: Meridian. Online text.
• Russell, Bertrand. 1912. The Problems of Philosophy, New York: Oxford University Press. Online text.
• Schiffer, Stephen. 1996. "Contextualist Solutions to Scepticism", Proceedings of the Aristotelian Society, 96:317-33.
• Steup, Matthias. 2005. "Knowledge and Scepticism", Contemporary Debates in Epistemology, Peter Sosa and Matthias Steup (eds.): 1-13.
• Tomberlin, James (ed.). 1999. Philosophical Perspectives 13, Epistemology, Blackwell Publishing.
• Wittgenstein, Ludwig. 1922. Tractatus-Logico Philosophicus, C.K. Ogden (trns.), Dover. Online text.

External links and references

Stanford Encyclopedia of Philosophy articles:

• Bayesian Epistemology - by William Talbott.
• Epistemology - by Matthias Steup.
• Evolutionary Epistemology - by Michael Bradie & William Harms.
• Feminist Epistemology and Philosophy of Science - by Elizabeth Anderson.
• Naturalized Epistemology - by Richard Feldman.
• Sense Data - by Michael Huemer.
• Social Epistemology - by Alvin Goldman.
• Virtue Epistemology - by John Greco.

Other links:

• What Is Epistemology? - a brief introduction to the topic by Keith DeRose.
• Certain Doubts - a group blog run by Jonathan Kvanvig, with many leading epistemologists as contributors.
• The Epistemology Page - by Keith DeRose.
• Epistemology Papers a collection of Michael Huemer's.
• Epistemology Introduction, Part 1 and Part 2 - by Paul Newall at the Galilean Library.
• Teaching Theory of Knowledge (1986) - Marjorie Clay (ed.), an electronic publication from The Council for Philosophical Studies.
• Epistemology: The Philosophy of Knowledge - an introduction at Groovyweb.
• Introduction to Theory of Knowledge - from PhilosophyOnline.
• Theory of Knowledge - an introduction to epistemology, exploring the various theories of knowledge, justification, and belief.
• A Theory of Knowledge by Clóvis Juarez Kemmerich, on the Social Science Research Network, 2006.
• An Introduction to Epistemology - by Paul Newall, aimed at beginners.
• Reformed Epistemology - by Tim Holt.
• Articles on Christian Epistemology - from solagratia.org.
• Contextualism in Epistemology - an article by Tim Black on the Internet Encyclopedia of Philosophy.
• Bibliography of papers on contextualism in epistemology - by Keith DeRose.
• Insensitive Semantics (2005) - a book by Herman Cappelen and Ernie Lepore, arguing against contextualism.

See also

• Algorithmic information theory
• Analytic tradition
• Bayesian probability
• Contextualism
• Eastern epistemology

• Ethics
• Evidentialism
• Evidentiality
• Gödel's incompleteness theorems
• Methodology

• Methods of obtaining knowledge
• Objectivist epistemology
• Perception
• Philosophy of science
• Reason

• Reliabilism
• Science education
• Scientific modeling
• Self-evidence
• Social epistemology

• Subjective idealism
• Transcendental idealism
• Virtue epistemology