The branch of philosophy dealing with the theory of knowledge - its sources, limits, kinds, and reliability. These central issues divide such major schools as empiricists, rationalists, and sceptics.
Epistemology or theory of knowledge is the branch of Western philosophy that studies the nature and scope of knowledge. The term "epistemology" is based on the Greek words "επιστημη or episteme" (knowledge) and "λόγος or logos" (account/explanation);
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, belief, and justification. It also deals with the means of production of knowledge, as well as skepticism about different knowledge claims. In other words, epistemology primarily addresses the following questions: "What is knowledge?", "How is knowledge acquired?", and "What do people know?".
Defining knowledge
The first question that will be dealt with is the question of what knowledge is.
Distinguishing knowing that from knowing how
In this article, and in epistemology in general, the kind of knowledge usually discussed is propositional knowledge, also known as "knowledge-that" as opposed to "know-how".
The distinction is between theoretical reason and practical reason, with epistemology being interested primarily in knowledge of the theoretical kind.
Belief
Sometimes, when people say that 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 the kind of belief usually dealt with in epistemology. The kind that is dealt with as such is where "to believe something" just means to think that it is true — e.g., to believe that the sky is blue is to think that the proposition, "The sky is blue," is true.
Belief is a part of knowledge. Consider the statement, "I know that P is true, but I don't believe that P is true." (See the article on Moore's paradox.)
Truth
Knowledge is distinct from belief. This is not the case with knowledge. For something to count as knowledge, it must be true.
Justified true belief
In Plato's dialogue Theaetetus, Socrates considers a number of theories as to what knowledge is, the last being that knowledge is true belief that has been "given an account of"—meaning explained or defined in some way. According to the theory that knowledge is justified true belief, in order to know that a given proposition is true, one must not only believe the relevant true proposition, but one must 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. Nevertheless, even if this belief turned out to be true, the patient would not have known that she would get well since her belief lacked justification.
Socrates rejected the theory that knowledge is true belief that has been given an account of. The theory that knowledge is justified true belief, on the other hand, was widely accepted as straightforwardly correct until the 1960s.
The Gettier problem
In his 1963 paper, "Is Justified True Belief Knowledge?", Edmund Gettier called into question the theory of knowledge that had been dominant among philosophers 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 it is necessary for knowledge of a proposition that one be justified in one's true belief in that proposition, it is not sufficient. More technically, Gettier claimed that the following account of knowledge is insufficient:
S knows that P if and only if:
P is true;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 come to be known as "Gettier cases", as counterexamples to the classical account of knowledge. Smith has excellent reasons to believe that Jones will get the job and, furthermore, believes the true proposition that Jones has ten coins in his pocket (he recently counted them). Smith has a justified true belief that the man with ten coins in his pocket will get the job; however, according to Gettier, Smith does not know that the man with ten coins in his pocket will get the job, because Smith's belief is "...true in virtue of the number of coins in Smith'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."
Responses to Gettier
The responses to Gettier have been varied. Usually, responses to Gettier have involved substantive attempts to provide a definition of knowledge aside from the classical one, either by recasting knowledge as justified true belief plus some fourth condition, or as something else altogether.
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, so the theory goes, a belief must not only be true and justified, the justification of the belief must necessitate its truth. (See Fallibilism, below, for more information.)
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.
Reliabilism
Reliabilism is a theory advanced by philosophers such as Alvin Goldman according to which 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, as per its name, this theory states that a true belief counts as knowledge only if it is produced by a reliable belief-forming process. Theoretically, Henry doesn't 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
The American philosopher Robert Nozick has offered the following definition of knowledge:
S knows that P if and only if:
P;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.
Finally, at least one philosopher, Timothy Williamson, has advanced a theory of knowledge according to which knowledge is not justified true belief plus some extra condition(s). In his book Knowledge and its Limits, Williamson argues that the concept of knowledge cannot be analyzed into a set of other concepts—instead, it is sui generis. Thus, though knowledge requires justification, truth, and belief, the word "knowledge" can't be, according to Williamson's theory, accurately regarded as simply shorthand for "justified true belief".
Externalism and internalism
On a last note: part of the debate over the nature of knowledge is a debate between epistemological externalists on the one hand, and epistemological internalists on the other. Externalists think that factors deemed "external", meaning outside of the psychological states of those who gain knowledge, can be conditions of knowledge. For example, an externalist response to the Gettier problem is to say that, in order for a justified, true belief to count as knowledge, it must be caused, in the right sort of way, by relevant facts. Internalists, contrariwise, claim that all knowledge-yielding conditions are within the psychological states of those who gain knowledge.
Acquiring knowledge
The second question that will be dealt with is the question of how knowledge is acquired. This area of epistemology covers what is called "the regress problem", issues concerning epistemic distinctions such as that between experience and apriority as means of creating knowledge and that between analysis and synthesis as means of proof, and debates such as the one between empiricists and rationalists.
The regress problem
The regress problem emerges in the context of asking for justification for every belief. If a given item of justification depends on another belief for its justification, one can also reasonably ask for this latter justification to be provided, and so forth. This appears to lead to an infinite regress, with each belief justified by some further belief. The skeptic will argue that since no one can complete such a chain, ultimately no beliefs are justified and, therefore, no one knows anything.
Some philosophers, notably Peter Klein in his "Human Knowledge and the Infinite Regress of Reasons", have argued that it's not impossible for an infinite justificatory series to exist.
Foundationalists respond to the regress problem by claiming that some beliefs that support other beliefs do not themselves require justification by other beliefs. Sometimes, these beliefs, labeled "foundational", are characterized as beliefs that one is directly aware of the truth 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 seems to its believer to be true. Others have argued that a belief is justified if it is based on perception or certain a priori considerations.
The chief criticism of foundationalism is that it allegedly leads to the arbitrary or unjustified acceptance of certain beliefs.
Another 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. Most coherentists now hold that an individual belief is not justified circularly, but 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.
A priori and a posteriori knowledge
For centuries, a distinction has been made between two kinds of knowledge: a priori and a posteriori. however, the terms may be roughly defined as follows:
A priori knowledge is knowledge that is independent of experience (that is, it is non-empirical). A posteriori knowledge is knowledge that is dependent on experience (that is, it is empirical).Analytic/synthetic distinction
Some propositions are such that we appear to be justified in believing them just so far as we understand their meaning. We seem to be justified in believing it to be true by virtue of our knowledge of what its terms mean.
Specific theories of knowledge acquisition
Empiricism
In philosophy generally, empiricism is a theory of knowledge emphasizing the role of experience. Certain forms treat all knowledge as empirical, while some regard disciplines such as mathematics and logic as exceptions.
Rationalism
Rationalists believe that knowledge is primarily (at least in some areas) acquired by a priori processes or is innate—e.g., in the form of concepts not derived from experience.
The extent to which this innate human knowledge is emphasized over experience as a means to acquire knowledge varies from rationalist to rationalist. Some hold that knowledge of any kind can only be gained a priori, while others claim that some knowledge can also be gained a posteriori.
Constructivism
Constructivism is a view in philosophy according to which all knowledge is "constructed" in as much as it is contingent on convention, human perception, and social experience.
General skepticism
Responses to general skepticism
Contextualism
Contextualism in epistemology is the claim that knowledge varies with the context in which it is attributed. (Opposed to this contextualism are several forms of what is called "invariantism", the theory 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.) The motivation behind contextualism is the idea that, in the context of discussion with an extreme skeptic about knowledge, there is a very high standard for the accurate ascription of 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.
Fallibilism
For most of philosophical history, "knowledge" was taken to mean belief that was true and justified to an absolute certainty. Early in the 20th Century, however, the notion that belief had to be justified as such to count as knowledge lost favour.
Practical applications
Far from being purely academic, the study of epistemology is useful for a great many applications.
Other common applications of epistemology include:
Mathematics and science History and archaeology Medicine (diagnosis of disease) Product testing (How can we know that the product will not fail?) Intelligence gathering
User Comments Add a comment…