A central issue in epistemology is to determine the components or essential features of declarative knowledge. This field of inquiry is called the
analysis of knowledge. It aims to provide the conditions that are
individually necessary and jointly sufficient for a state to amount to declarative knowledge. In this regard, it is similar to how a chemist breaks down a sample by identifying all the chemical elements composing it. A traditionally influential view states that declarative knowledge has three essential features: it is (1) a
belief that is (2)
true and (3)
justified. This position is referred to as the justified-true-belief theory of knowledge and is often seen as the standard view. This view faced significant criticism following a series of counterexamples given by
Edmund Gettier in the latter half of the 20th century. In response, various alternative theories of the elements of declarative knowledge have been suggested. Some see justified true belief as a necessary condition that is not sufficient by itself and discuss additional components that are needed. Another response is to deny that justification is needed and seek a different component to replace it. Some theorists, like
Timothy Williamson, reject the idea that declarative knowledge can be deconstructed into various constituent parts. They argue instead that it is a basic and unanalyzable epistemological state.
Belief One commonly accepted component of knowledge is belief. In this sense, whoever knows that whales are animals automatically also believes that whales are animals. A belief is a mental state that affirms that something is the case. As an attitude toward a proposition, it belongs to the subjective side of knowledge. Some theorists, like Luis Villoro, distinguish between weak and strong beliefs. Having a weak belief implies that the person merely presumes that something is the case. They guess that the claim is probably correct while acknowledging at the same time that they might very well be mistaken about it. This contrasts with strong belief, which implies a substantial commitment to the believed claim. It involves
certainty in the form of being sure about it. For declarative knowledge, this stronger sense of belief is relevant. A few epistemologists, like
Katalin Farkas, claim that, at least in some cases, knowledge is not a form of belief but a different type of mental state. One argument for this position is based on statements like "I don't believe it, I know it", which may be used to express that the person is very certain and has good reason to affirm this claim. However, this argument is not generally accepted since knowing something does not imply that the person disbelieves the claim. A further explanation is to hold that this statement is a linguistic tool to emphasize that the person is well-informed. In this regard, it only denies that a weak belief exists without rejecting that a stronger form of belief is involved.
Truth Beliefs are either true or false depending on whether they accurately represent reality. Truth is usually seen as one of the essential components of knowledge. This means that it is impossible to know a claim that is false. For example, it is possible to believe that
Hillary Clinton won the
2016 US Presidential election but nobody can know it because this event did not occur. That a proposition is true does not imply that it is
common knowledge, that an irrefutable
proof exists, or that someone is thinking about it. Instead, it only means that it presents things as they are. For example, when flipping a coin, it may be true that it will land heads even if it is not possible to predict this with certainty. Truth is an objective factor of knowledge that goes beyond the mental sphere of belief since it usually depends on what the world outside the person's
mind is like. Some epistemologists hold that there are at least some forms of knowledge that do not require truth. For example, Joseph Thomas Tolliver argues that some mental states amount to knowledge only because of the causes and effects they have. This is the case even if they do not represent anything and are therefore neither true nor false. A different outlook is found in the field of the
anthropology of knowledge, which studies how knowledge is acquired, stored, retrieved, and communicated. In this discipline, knowledge is often understood in a very wide sense that is roughly equivalent to understanding and
culture. In this regard, the main interest is usually about how people ascribe truth values to meaning-contents, like when affirming an assertion, independent of whether this assertion is true or false. Despite these positions, it is widely accepted in epistemology that truth is an essential component of declarative knowledge.
Justification In epistemology, justification means that a claim is supported by
evidence or that a person has good reasons for believing it. This implies some form of appraisal in relation to an evaluative standard of
rationality. For example, a person who just checked their bank account and saw that their balance is 500 dollars has a good reason to believe that they have 500 dollars in their bank account. However, justification by itself does not imply that a belief is true. For example, if someone reads the time from their clock they may form a justified belief about the current time even if the clock stopped a while ago and shows a false time now. If a person has a justified belief then they are often able to articulate what this belief is and to provide arguments stating the reasons supporting it. However, this ability to articulate one's reasons is not an essential requirement of justification. Justification is usually included as a component of knowledge to exclude lucky guesses. For example, a compulsive gambler flipping a coin may be certain that it will land heads this time without a good reason for this belief. In this case, the belief does not amount to knowledge even if it turns out that it was true. This observation can be easily explained by including justification as an essential component. This implies that the gambler's belief does not amount to knowledge because it lacks justification. In this regard, mere true opinion is not enough to establish knowledge. A central issue in epistemology concerns the standards of justification, i.e., what conditions have to be fulfilled for a belief to be justified.
Internalists understand justification as a purely subjective component, akin to belief. They claim that a belief is justified if it stands in the right relation to other mental states of the believer. For example, perceptual experiences can justify beliefs about the perceived object. This contrasts with externalists, who claim that justification involves objective factors that are external to the person's mind. Such factors can include
causal relations with the object of the belief or that reliable cognitive processes are responsible for the formation of the belief. A closely related issue concerns the question of how the different mental states have to be related to each other to be justified. For example, one belief may be supported by another belief. However, it is questionable whether this is sufficient for justification if the second belief is itself not justified. For example, a person may believe that Ford cars are cheaper than BMWs because they heard this from a friend. However, this belief may not be justified if there is no good reason to think that the friend is a reliable source of information. This can lead to an
infinite regress since whatever reason is provided for the friend's reliability may itself lack justification. Three popular responses to this problem are
foundationalism,
coherentism, and
infinitism. According to foundationalists, some reasons are foundational and do not depend on other reasons for their justification. Coherentists also reject the idea that an infinite chain of reasons is needed and argue that different beliefs can mutually support each other without one being more basic than the others. Infinitists, on the other hand, accept the idea that an infinite chain of reasons is required. Many debates concerning the nature of declarative knowledge focus on the role of justification, specifically whether it is needed at all and what else might be needed to complement it. Influential in this regard was a series of
thought experiments by Edmund Gettier. They present concrete cases of justified true beliefs that fail to amount to knowledge. The reason for their failure is a type of
epistemic luck. This means that the justification is not relevant to whether the belief is true. In one thought experiment, Smith and Jones apply for a job and before officially declaring the result, the company president tells Smith that Jones will get the job. Smith saw that Jones has 10 coins in his pocket so he comes to form the justified belief that the successful candidate has 10 coins in his pocket. In the end, it turns out that Smith gets the job after all. By lucky coincidence, Smith also has 10 coins in his pocket. Gettier claims that, because of this coincidence, Smith's belief that the successful candidate has 10 coins in his pocket does not amount to knowledge. The belief is justified and true but the justification is not relevant to the truth.
Others In response to
Gettier's thought experiments, various further components of declarative knowledge have been suggested. Some of them are intended as additional elements besides belief, truth, and justification while others are understood as replacements for justification. According to defeasibility theory, an additional factor besides having evidence in favor of the belief is that no
defeating evidence is present. Defeating evidence of a belief is evidence that undermines the justification of the belief. For example, if a person looks outside the window and sees a rainbow then this impression justifies their belief that there is a rainbow. However, if the person just ate a
psychedelic drug then this is defeating evidence since it undermines the reliability of their experiences. Defeasibility theorists claim that, in this case, the belief does not amount to knowledge because defeating evidence is present. As an additional component of knowledge, they require that the person has no defeating evidence of the belief. Some theorists demand the stronger requirement that there is no true proposition that would defeat the belief, independent of whether the person is aware of this proposition or not. A closely related theory holds that beliefs can only amount to knowledge if they are not inferred from a falsehood. A further theory is based on the idea that knowledge states should be responsive to what the world is like. One suggested component in this regard is that the belief is safe or sensitive. This means that the person has the belief because it is true but that they would not hold the belief if it was false. In this regard, the person's belief tracks the state of the world. Some theories do not try to provide additional requirements but instead propose replacing justification with alternative components. For example, according to some forms of
reliabilism, a true belief amounts to knowledge if it was formed through a reliable cognitive process. A cognitive process is reliable if it produces mostly true beliefs in actual situations and would also do so in
counterfactual situations. Examples of reliable processes are perception and reasoning. An outcome of reliabilism is that knowledge is not restricted to humans. The reason is that reliable belief-formation processes may also be present in other animals, like dogs, apes, or rats, even if they do not possess justification for their beliefs.
Virtue epistemology is a closely related approach that understands knowledge as the manifestation of
epistemic virtues. It agrees with regular forms of reliabilism that knowledge is not a matter of luck but puts additional emphasis on the evaluative aspect of knowledge and the underlying skills responsible for it. According to causal theories of knowledge, a necessary element of knowing a fact is that this fact somehow caused the knowledge of it. This is the case, for example, if a belief about the color of a house is based on a perceptual experience, which causally connects the house to the belief. This causal connection does not have to be direct and can be mediated through steps like activating memories and drawing
inferences. In many cases, the goal of suggesting additional components is to avoid cases of epistemic luck. In this regard, some theorists have argued that the additional component would have to ensure that the belief is true. This approach is reflected in the idea that knowledge implies a form of certainty. But it sets the standards of knowledge very high and may require that a belief has to be
infallible to amount to knowledge. This means that the justification ensures that the belief is true. For example,
Richard Kirkham argues that the justification required for knowledge must be based on
self-evident premises that
deductively entail the held belief. Such a position leads to a form of
skepticism about knowledge since the great majority of regular beliefs do not live up to these requirements. It would imply that people know very little and that most who claim to know a certain fact are mistaken. However, a more common view among epistemologists is that knowledge does not require infallibility and that many knowledge claims in everyday life are true. == Types ==