Philosophy of Knowledge - Epistemology

[Petros Agapetos]

Beliefs

Belief is the state of mind in which a person things something to be the case, with or without there being empirical evidence to prove that something is the case with factual certainty. Beliefs are mental representations of an attitude positively oriented towards the likelihood of something being true. Beliefs refer to personal attitudes associated with true or false ideas and concepts. Beliefs do not require active introspection and circumspection.

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Theories of Knowledge
Knowledge can be categorized as 1. Propositional knowledge (knowledge-that), 2. Knowledge by acquaintance (familiarity), and 3. Procedural Knowledge (ability knowledge, knowledge-how). Knowledge requires true beliefs because knowledge is a success term (successfully corresponds to reality). Knowledge involves acquisition of truth. There may be many ways of defending truth claims, but only really one proper way to define them, through correspondence to reality.

Truth as Correspondence:
Propositions are the ultimate truth bearers. Whereas, sentences, statements, and beliefs, get their truth or falsity derivatively. Thus beliefs and sentences are true or false depending upon their propositional content, and the relation of that content to the facts. Propositional beliefs have propositional content. Sentences are used to express certain thoughts of ideas. Philosophers use the word proposition to refer to these items. Belief is fundamentally a relation to a proposition. Beliefs are fundamentally attitudes one takes toward propositions. Facts are any states of affairs which happen to be the case whether known or not known.

Truth as Coherence:
Truth is a system or web of propositions or beliefs each of which either necessarily implies the others or stand in some weaker relation of mutual support. An odd implication of coherence theory is that truth, like coherence, admits of degrees.

Main Objection to Coherence Theory:
The possibility of two (i) equally coherent, (ii) mutually exclusive, and (iii) maximally developed belief systems. The coherentist may not be able to distinguish truth from a good work of fiction.

Knowledge entails justification (good reason). Mere opinion does not count even if it happens to be right. Justification is a normative term: (i) Justification is a matter of ‘ought’ rather than ‘is’, (ii) epistemic justification is analogous to ethical justification: it implies meeting a standard. This raises the issue of what the correct standard is (the problem of criterion) and whether it can be met (the problem of skepticism).

It is wrong always for anyone to believe anything upon insufficient evidence. Thus knowledge is a true belief that is held for good reason (that is to say, a well justified reason).

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Is Justified True Belief Always Sufficient to Constitute Knowledge?
Gettier cases demonstrate that justification and truth are necessary but not sufficient for a belief to be knowledge.

Gettier Case #1:
Smith has good reason to believe Jones will get promoted. Jones told Smith what the employer told informed him. Smith believes based on good reason (he has seen it) that Jones has 10 coins in his pocket. Smith has good grounds to believe that Jones will get promoted having 10 coins in his pocket. Thus Smith believes that the person who will get promoted has 10 coins in his pocket. The twist here is that, the employer, ever since letting Jones know of his upcoming promotion, has changed his mind, and decided to promote not Jones, but Smith instead. Another twist is that Smith also has 10 coins in his pocket, however he does not know this, but we do. The question then becomes did Smith know that he was going to be promoted? – No. Did Smith know that the person to be promoted has 10 coins in his pocket? – No. But was Smith justified in believing it? – Sure, he believed on sufficient evidence for such a scenario that Jones is the one having 10 coins in his pocket who was going to be promoted. Did Smith believe it? - Yes. Is it true that the person getting promoted has 10 coins in his pocket? – Yes. So, we have a situation, where Smith justifiably believed something to be true, which ended up being true, which he did not know, since he did not know it was he himself who was going to be promoted who had 10 coins in his pocket. Why does the belief that Smith justifiably held not count as knowledge? Knowledge is a value term, it cannot just accidentally happen to correspond to reality (through epistemic luck), even when the belief is sufficiently well justified for a person in the given situation. Smith was not irresponsible in forming his beliefs yet he did not really know and was luckily tied to the universe. This is why Smiths belief cannot count as knowledge.

Gettier Case #2
Smith believes based on good evidence, such as being close friends with Jones, that Jones owns a Ford. Smith forms this belief in an epistemically justified fashion. Smith then entertain the disjunctive proposition: “either Jones owns a Ford or Jones is located in Barcelona”. Suppose, that unbeknownst to Smith, Jones has actually sold his Ford now and is using a rental vehicle, a Mercedes Benz. Also unbeknownst to Smith, Jones happens to be in Barcelona at the time Smith is considering the proposition. The truth is Jones is actually in Barcelona watching a bull fight and he no longer owns a Ford. However, since the proposition that Smith is considering is a disjunctive proposition, the entire proposition is true, if and only if at least one of the parts of the proposition (not containing the logical operator ‘or’) is true. Is Smith justified in believing that Jones “owns a Ford or is located in Barcelona” – Yes, because Smith had first person witness testimony as his evidence to substantiate his belief that Jones still owns the Ford. Smith has no evidence of Jones being in Barcelona, however since this is a disjunctive proposition, the belief that is justifiably taken to be true comes from the first part of the entire proposition, the part in which “Jones owns a Ford”. The part of the proposition which is actually in fact true is the second part, that “Jones is located in Barcelona”, however Smith does not know this nor even believes this. So the truth maker of the disjunctive proposition is Jones’s being in Barcelona, and not Smiths belief about Jones owning a Ford. The question then becomes is it true that “either Jones owns a Ford or he is located in Barcelona?” – Yes, it is true. Is it justified for Smith to hold this – Yes, by virtue of him evidence for the first part of the disjunctive proposition. Is it believed? - Even though Smith does not believe the actually true part of the proposition (the second part), Smith believes the first part, which happened not to be true at the time he was considering the proposition. Therefore, a justified true belief regarding the proposition did not constitute knowledge because it did not reliably track the truth, and if a belief does not track or acquire true information, then it ought not be considered knowledge, because knowledge is a value term that stands for the acquisition of truth.

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Solutions to the Gettier Problems:
One option is the “No False Premise-Belief” solution which revises the traditional analysis of knowledge as justified true belief, such that justified true belief (JTB) is necessary but not sufficient to count as knowledge if the belief is based on or caused by a false premise or belief.

The problem with this solution can be illustrated with another Gettier example: A person sees a dog dressed in sheep’s clothing in a field where there are actual sheep also, however they observer does not see the actual sheep there because they are hidden from his view behind a rock. So as the observer says “That field has a sheep in it”. This belief is justified based on immediate perceptual experience of reality and what is reasonable to expect such experiences to serve a person who is merely driving by and noticing the dog in sheep’s clothing. The belief is actually true, there are sheep in the field, however he did not point to a real one. However, the belief that there is a sheep in the field is based on a false premise (that the dog in sheep’s clothing was a sheep). Is it true that the observer knew there was a sheep in the field? We form beliefs on the basis of perception all the time, and not on the basis of arguing ourselves into a belief. This Gettier case demonstrates that the above modified definition of knowledge still does not suffice for this case to establish knowledge, and that the JTB theory must be amended further, in addition to there not being any false premises or beliefs, and that something extra is required for the observer’s belief to constitute knowledge.

However, consider this, would the observer have these reasons for his belief, if he were right? Contextualism holds that knowledge requires having good reasons for dismissing “relevant alternatives” for why one has the reasons. What’s relevant? What is needed to be ruled out with good reason? Relevance depends on context. Consider that apparently the more you care, the less you know.

Revising the Justification Criterion:
A belief shall be called justified just in case it is the product of a psychological process which tends to produce true beliefs. The use of the word ‘tends’ here indicates probability.

Can future facts cause my present beliefs? For example, consider the proposition “The sun will rise tomorrow. “This is done through an inductive probability-based process of reasoning from the past to the future which relies on the assumption of the uniformity of nature.

Or consider, the proposition, “I will die one day.” This is conclusion is reached through an inductive probability-based process of reasoning from the seen to the unseen (or from the past to the future).

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Epistemology – the Study of Knowledge
Given that S = the subject, p = the proposition known, what are the necessary and sufficient conditions for knowledge for ‘S to know that p’.

The Tripartite Analysis of Knowledge as Justified True Belief (Traditional Analysis)
Justified true belief are individually necessary and jointly sufficient condition for knowledge under the traditional analysis of knowledge (TK, as in Traditional Knowledge). How does justification play its role in knowledge? S being correct in believing that p might merely be a matter of luck. According to evidentialism, what makes a belief justified is the possession of evidence. Belief is justified to the degree it first S’s evidence. On the other hand, (non-traditional analysis of knowledge, NTK, as in Non-Traditional Knowledge) one may conceive of the role of justification differently. Its role is to ensure the subject’s belief has a high objective probability of truth and therefore, if true, it is not true merely by luck. One prominent idea is that this is accomplished if and only if a belief originates in reliable cognitive processes or faculties. This view is known as reliabilism.

The Tripartite Analysis of Knowledge as JTB has been shown to be incomplete. In Gettier cases, JTB does not suffice to constitute knowledge. Gettier cases arise because neither a possession of evidence nor origination in reliable faculties is sufficient for ensuring that a belief is not true because of luck.

Reliable cognitive processes (knowledge by acquaintance). Solving the Gettier problems requires a fourth condition. According to some NTK theorists, it calls for refining the concept of reliability. Reliabilitists could say that one’s belief is not justified in his environment, because then and there, vision (for example) is not reliable when it comes to discerning what was seen from what may have merely appeared so. Some NTK theorists bypass the justification condition altogether. They would say that if we conceive of knowledge as reliably produced true belief, there is no need for justification. Reliabilism then comes in two forms: 1. As a theory of Justification, and 2. As a Theory of Knowledge. As a theory of justification, reliabilism views justification to be an important ingredient of knowledge, but unlike NTK, it grounds justification solely in reliability. As a theory of knowledge, reliabilism asserts that justification is not necessary for knowledge, rather reliably produced true beliefs are sufficient for knowledge, provided the notion of reliability is suitably refined to rule out Gettier cases.

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What is Justification?
We distinguish between two different issues: First, what do we mean when we use the word “justification”. Second, what makes beliefs justified?

The Deontological Understanding of Justification:
S is justified in believing that p if and only if S believes that p, while it is not the case that S is obliged to refrain from believing that p.
Deontology is the normative ethical position that judges the morality of an action based on the action's adherence to a rule or rules. It is sometimes described as "duty-" or "obligation-" or "rule-" based ethics, because rules "bind you to your duty."

What kind of obligations are relevant when we wish to assess whether a belief (rather than an action) is justified or unjustified? Whereas, when we evaluate an action, we are interested in assessing the action from either a moral or a prudential point of view, when it comes to beliefs, what matters is the pursuit of truth. We ought to believe in accord with our evidence. We need an account of what our evidence consists of or we ought to follow the correct epistemic norms. There are obligations that the truth-aim imposes on us. The relevant kinds of obligations then are those that arise when we aim at having true beliefs. Exactly what though must we do in the pursuit of this aim? What is evidence? And what are the correct epistemic norms? Epistemically defective beliefs are those that are formed using unreliable and intellectually faulty methods.

View #1. Beliefs are not acts of volition like actions. Beliefs simply arise in or happen to us. Beliefs are not suitable for deontological evaluations.
View #2. The lack of control over our beliefs is not an obstacle to using them as justification in its deontological sense.
View #3. Others yet argued that it is a mistake to think that we can control our beliefs any less than our actions.

The Non-Deontological Understanding of Justification
S is justified in believing that p if and only if S believes that p on a basis that properly probabilifies S’s belief that p. What does proper probabilification amount to?

Evidence vs. Reliability
What makes justified beliefs justified? According to Evidentialists, it is the possession of evidence. What is it though to possess evidence for believing that p? Some Evidentialists would say it is to be in a mental state that represents p as being true. For example, the coffee in my cup tastes sweet, so I conclude the coffee is sweet, such that it could taste sweet to others as well. If one has memory of having been threatened, then one has evidence for a belief about the past in which the threat occurred. In this view, evidence consists of perceptual introspective, memorial, intuitional experiences, and to possess evidence is to have an experience of that kind. So according to evidentialism, what makes one justified in believing that p as being true.

Reliabilists, on the other hand, would deny that justification is solely a matter of having suitable experiences. Rather, they hold that a belief is justified if and only if it results from cognitive origin that is reliable: an origin that tends to produce true beliefs and therefore properly probabilifies the belief. But according to reliabilist theorists (standard form of reliabilism), what makes beliefs justified is not the possession of evidence, but the fact that the types of processes in which they originate – perception, introspection, memory, and rational intuition – are reliable.

Internalism vs. Externalism
Internalists claim that justification is internal, externalists deny this. To understand what the internal-external distinction amounts to, we need to bear in mind that when a belief is justified, there is something that makes the belief justified. Likewise, if a belief is not justified there is something that makes it unjustified. Let’s call the things that a belief justified or unjustified J-factors. The dispute over whether justification is internal or external is a dispute about what the J-factors are.


Internalism (J-factors are internal)
Two approaches are distinguished: First, J-factors are always recognizable on reflection. Hence, assuming certain further premises, justification itself is always recognizable on reflection. Second, justification is internal because J-factors are always mental states. Let’s call the former “accessibility internalism” and the latter “mentalist internalism”. Externalists deny that J-factors meet either one of these conditions.

Evidentialsm is typically associated with Internalism, while Reliabilism is typically associated with Externalism.

Evidentialism says at minimum two things:
E1. Whether one is justified in believing p depends on one’s evidence regarding p.
E2. One’s evidence consists of one’s mental states.

By virtue of (E2), Evidentialism is clearly an instance of Mentalist Internalism. Whether Evidentialism is also an instance of Accessibility Internalism is more complicated issue. The conjunction of (E1) & (E2) by itself implies nothing about the recognizability of justification.
Among traditional analysts of knowledge (TK), evidentialism enjoys wide-spread sympathy. TK theorists tend to endorse the following two claims: Luminosity and Necessity:

Luminosity - One’s own mind is cognitively luminous. Relying on introspection, one can always recognize on reflection what mental state one is in.
Necessity – A priori recognizable, necessary principles say what is evidence for what. Relying on a priori insight, one can therefore always recognize on reflection whether one’s mental states are evidence for p.
Although (E1) and (E2) by themselves do not imply Access Internalism, it is quite plausible to maintain that Evidentialism, when embellished with Luminosity and Necessity, becomes an instance of Access Internalism.


Why is Reliabilism an Externalist Theory?
Reliabilism says that justification of one’s beliefs is a function of not one’s evidence, but the reliability of one’s belief sources, such as memorial, perceptual, and introspective states and processes. Whereas, the sources might quality as mental, their reliability does not. Therefore, reliabilists reject Mentalist Internalism. Moreover, if the justification of one’s belief is determined by the reliability of one’s beliefs sources, justification will not always be recognizable. Hence reliabilists also reject Access Internalism.

If Evidentialism is true, a subject who is radically deceived will be misled about what is actually the case, but not about what he is justified in believing. If, on the other hand, Reliabilism is true, then such a subject will be misled about both what is actually the case and what he is justified in believing.
Demonstration: Karl* is a brain in a vat. His body has been discarded, and his brain is connected to the Matrix super-computer which realizes sense data creating the illusion that they are coming from an external world.

Evidentialism implies that Karl* is justified in believing he has hands, even though his body was discarded (and brains don’t have hands). For even though Karl* is deceived about his external situation, he is not deceived about his evidence: the way things appear to him in his perceptual experiences. This illustrates the internality of evidentialist justification.

Reliabilism, on the other hand, suggests that Karl*’s answer is incorrect. Karl*’s belief that he has hands originates in cognitive processes (such as seeing and feeling his not actually existing hands) that now yield virtually no true beliefs. To the extent that this implies their unreliability, the resulting beliefs are unjustified. Consequently, he is deceived not only about his external situation (his not actually having hands), but also about the justificational status of his belief that he has hands. This illustrates the externality of reliabilist justification.


Why Internalism?
Argument 1. Justification is deontological: it is a matter of duty fulfillment. But duty fulfillment is internal. Therefore, justification is internal.
Argument 2. Karl*’s belief that he has hands is justified as Karl’s belief is justified. Karl* is internally the same as Karl (while externally quite different). Therefore, internal factors are what justify beliefs.
Argument 3. Since justification resulting from the possession of evidence is internal justification, internalism can be supported by way of making a case for evidentialism.
Evidentialists would appeal to cases in which a belief is reliably formed but not accompanied by any experiences that would qualify as evidence. They would say, it is not plausible to claim that in cases like that, the subject’s belief is justified. Hence such cases show, according to evidentialists, that a belief can’t be justified unless it is supported by the evidence.

Why Externalism?
Argument 1. It is possible for people to hold beliefs that are not justified in the way that evidentialists conceive of justification. Therefore, we must conclude that the justification their beliefs enjoy is external to them: resulting not from the possession of evidence, but from origination in reliable processes.
Argument 2. Externalists would say that what we want from justification is the kind of objective probability needed for knowledge and only external conditions on justification imply this probability. So justification has external conditions.

[Petros Agapetos]

The Structure of Knowledge and Justification

Foundationalism
Our justified beliefs are structured like a building. They are divided into a foundation and a superstructure: the latter resting upon the former. Beliefs belonging to the foundation are basic. Beliefs belonging to the superstructure are non-basic and receive justification from the justified beliefs in the foundation.
For a foundationalist account of justification to be plausible, it must solve two problems:
1) By virtue of exactly what are basic beliefs justified?
2) How do basic beliefs justify non-basic beliefs?
What makes a justified belief basic in the first place? According to one approach, what makes a justified belief basic is that it doesn’t receive its justification from any other beliefs.

Doxastic Basicality (DB):
S is justified that p is basic if and only if S’s belief that p is justified without owing its justification to any of S’s other beliefs. Doxastic Basicality tells us that B is a basic belief iff it does not owe its justification to any other beliefs one has. So, if B is indeed basic, there might be some item or other to which B owes justification, but that item would not be another belief one has. Note that DB tells us merely how B is not justified, and it says nothing about how B is justified. DB therefore does not answer the question. What we need in addition to DB is an account of what it is that justifies a belief such as B.

Foundationalist Camp of Thought #1. According to one strand of foundationalist thought B is justified because it can’t be false, doubted, corrected by others. So B is justified because B carries with it an epistemic privilege such as infallibility, indubitability, or incorrigibility. The idea is that B is justified by virtue of tis intrinsic nature which makes it possess some kind of epistemic privilege.

Demonstration: Suppose you see my hat and say “this hat looks blue to me”. Note that B is not a belief about the hat, rather it is a belief about how the hat appears to you. So B is an introspective belief about a perceptual experience of yours. A subject’s basic beliefs are made up of introspective beliefs about the subject’s own mental states, of which perceptual experiences make up one subset. Other mental states about which a subject can have basic beliefs include such things as having a headache, being tired, feeling pleasure, or having a desire for a cup of coffee. Beliefs about external objects do not and indeed cannot qualify as basic, for it is impossible for such beliefs to own the kind of epistemic privilege needed for the stats of being basic.

Foundationalist Camp of Thought #2. According to another strand of foundationalist thought B is justified not by virtue of possessing some kind of privileged status, but by some further mental states of yours. That mental state however is not a further belief of yours, rather it is the very perceptual experience that B is about: the hat’s looking blue to you.

Let (E) represent the experience of seeing a blue hat. According to this alternative proposal (B) and (E) are distinct mental states. The idea is that which justifies (B) is (E). Since (E) is an experience and not a belief of yours, B is basic, according to doxastic Basicality (DB).

Let’s call the two version of foundationalism we have distinguished: “Privilege Foundationalism” and “Experiential Foundationalism”. Privilege Foundationalism restricts basic beliefs about one’s own mental states. Experiential Foundationalism restricts basic beliefs to beliefs about one’s own mental states. Experiential Foundationalism is less restrictive. According to it, beliefs about external objects can be basic as well.

Suppose that instead of (B) you believe (H): “The hat is blue”, rather than believing (B): “The hat looks blue to me”. Unlike (B), (H) is about the hat itself, and not the way it appears to one. Such a belief (H) is not one about which we are infallible or otherwise epistemically privileged. Privilege Foundationalism would therefore classify (H) as non-basic. It is however quite plausible to think that € justifies not only (B) but also (H). If (E) is indeed what justifies (H) and (H) does not receive additional justification from any further beliefs one has, then (H) qualifies as basic, under Doxastic Basicality (DB).

Experiential Foundationalism them combines two crucial ideas:
(i) When justified belief is basic, its justification is not owed to any other belief
(ii) What in fact justifies basic beliefs are experiences.

Under ordinary circumstances, perceptual beliefs such as (H) “The hat is blue” are not based on any further beliefs (not experiences) about one’s own perceptual experiences. It is unclear therefore how Privilege Foundationalism can account for ordinary perceptual beliefs like (H).

Experiential Foundationalism, on the other hand, has no trouble at all explaining how ordinary perceptual beliefs are justified: they are justified by perceptual experiences that give rise to them. This could be viewed as a reason for preferring Experiential Foundationalism to Privilege Foundationalism.

An Alternative Conception of Basicality – Epistemic Basicality (EB)
S’s justified belief that p is basic if and only if S’ justification for believing that p does not depend on justification S possesses for belief a further proposition q. Thus, EB makes it more difficult for a belief to be basic that DB.

The J-Question: Why are Perceptual Experiences a Source of Justification?
From a Coherentist point of view, we might answer the J-Question as follows: Perceptual experiences are a source of justification because we are justified in believing them to be reliable. As we will see later on, making perceptual justification depend on the existence of reliability attributing beliefs is quite problematic. There is however an alternative answer to the J-Question that appeals to reliability without making perceptual justification depend upon beliefs that attribute reliability to perceptual experiences. According to this second answer, perceptual experiences are a source of justification because we have justification for taking them to be reliable. This is what’s known as the “Compromise Position” between foundationalism and its competitor, coherentism. It states that if one’s perceptual experiences are a source of justification to one, one must have justification for believing them to be reliable.

What might give us justification for thinking that our perceptual experiences are reliable?
We remember that our perceptual experiences have served us well in the past. We are supposing then, that justification for attributing reliability to our perceptual experiences consists of memories of perceptual success. We rely on our senses based on their continued reliability of producing effective results.

According to the “Compromise Position” between Foundationalism and Coherentism, it is never a perceptual experience (E) by itself that justifies a perceptual belief, but only (E) in conjunction with suitable track record memories that give one justification for considering (E) reliable. According to the “Compromise Position”, one’s having justification for (H) depends on one’s having justification for believing something else in addition to (H), namely that one’s experiences are reliable. As a result, (H) is not basic in the sense defined by epistemic basicality (EB), however, (H) might still be basic in the sense defined by doxastic basicality (DB).

Let (E) again stand for the experience of say a hat looking blue to one, and (H) for one’s belief that the hat is in fact blue. According to the “Compromise Position”, (E) justifies (H) if and only if (E) is accompanied by track-record memories (M) that give one justification for attributing reliability to one’s experiences. So what justifies (H) is the conjunction of (E) and (M). As long as one’s justification for (H) is owed solely to (E) and (M), neither of which include any beliefs, DB tells us that (H) is basic. It follows that an Experiential Foundationalist who wishes to classify beliefs such as (H) as basic cannot adopt the “Compromise Position”. And Experiential Foundationalist would have to say that (E) by itself is sufficient for making (H) a justified belief.

How do Experiential Foundationalists who prefer Epistemic Basicality to Doxastic Basicality answer the J – Question? Because of the way they conceive of basicality, the Experiential Foundationalists cannot say that perceptual experiences are a source of justification for one because one has a reason (R) for believing that they do. For (R) would be a justification for believing something else – the very thing, according to (EB), is an obstacle to basicality. One option for an (EB)- Foundationalist would be to endorse externalism. If they do, they could say that perceptual experiences are a source of justification if and only if they are of types that are reliably associated with true resulting beliefs. On that view, it would be the fact of reliability, not evidence of reliability, that makes perceptual experiences a source of justification because it could not be otherwise: it is a necessary truth that certain perceptual experiences can justify certain perceptual beliefs. This would be an internalist answer to the J-Question because perceptual experiences would be a source of justification whether or not they are reliable.

How is Justification transferred from basic to non-basic beliefs? There are TWO options:
First, if we take the relation to be deductive: then each of the non-basic beliefs would have to be such that it can be deduced from one’s basic beliefs. This seems excessively demanding.
Second, Foundationalists typically conceive of the link between the foundation and the superstructure in non-deductive terms. They would say that for a basic belief B to justify a non-basic belief B*, it is not necessary that B entails B*, rather it is sufficient that given B, it is likely that B* is true.

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Coherentism
Foundationalism says that knowledge and justification are structure like a building, consisting of a superstructure that rests upon a foundation. According to Coherentism, this metaphor gets things wrong, and instead knowledge and justification are structured as a web, where the strength of any given area depends on the strength of the surrounding areas. Coherentists then deny there are such things as basic beliefs. As we say in Foundationalism, there are two different ways of conceiving of basicality. Consequently, there are two corresponding ways of construing coherentism: (i) as the denial of doxastic basicality – called Doxastic Coherentism, and (ii) as the denial of epistemic basicality – called Epistemic Coherentism.
Doxastic Coherentism
Every justified belief receives its justification from other beliefs in its epistemic neighbourhood.
Demonstration: Let (H) be “The hat is blue”. Let’s agree that (H) is justified. According to Coherentism, (H) receives its justification from other beliefs in the epistemic vicinity of (H). These beliefs constitute one’s evidence or one’s reasons for taking (H) to be true.

Q: Which beliefs might make up this set of justification –conferring neighbourhood of beliefs?

Approach #1 to Q: Inference to the Best Explanation:
Such inferences generate what is called “Explanatory Coherence”. According to this approach, we must suppose one forms a belief about the way the hat appears to one in one’s perceptual experiences, and a second belief to the effect that one’s perceptual experience, that hat’s looking blue to one, is best explained by the assumption that (H) is true (the hat is actually blue). So the relevant set of beliefs is as follows:
1) I am having a visual experience (E): The hat looks blue to me.
2) My having the experience (E) is best explained by assuming that (H) is true.

There are of course alternative explanations as to why one has the experience (E). Perhaps, one is hallucinating that the hat is blue. Perhaps and evil demon makes the hat appear blue to one, while in reality it is red. Or perhaps one is the type of person to whom all hats look blue to him, etc. An explanatory coherentist would say that, compared with these alternatives, the hat’s being blue is a superior explanation. That is how one is justified in believing (H), on the Coherentist view.
One problem for the explanatory coherentist is to make us understand, in non-epistemic terms, why the favored explanation is really better than the competing ones. What we need is a general and principled account of what makes one explanation better than others. The general idea would be this:

- If there are two competing explanations E1 and E2.
- If E1 consists of or induces a proposition that one is not justified in believing, whereas E2 does not.
- Then E2 is a better explanation than E1.

However, there is a problem with this analysis: It puts the cart before the hoarse: it puts something inconsequential as more important than something essential. Explanatory Coherentism is supposed to make us understand where justification comes from, but it doesn’t do that if it accounts for the difference between better and worse explanations by making use of the difference between justified and unjustified beliefs. If Explanatory Coherentism were to proceed in this way, it would be a circular and thus uninformative account of justification. So the challenge to which Explanatory Coherentism must rise is to give an account, without using the concept of justification, of what makes an explanation better than another.

Q: Which beliefs might make up a proper set of justification –conferring vicinity of beliefs?

Approach #2 to Q: Reliability Coherentism:
Recall what a subject’s justification for believing p is all about: possessing a link between belief that p and the truth of p. Suppose the subject knows that the origin of his belief is reliable. So he knows that beliefs coming from this source tend to be true. Such knowledge would give one an excellent link between the belief and its truth. So we might say that the neighbourhood of beliefs which confer justification on (H) are the following:

1. I am having a visual experience (E): The hat looks blue to me.
3. Experiences like (E) are reliable.

Call Coherentism of this kind “Reliability Coherentism”. If you believe (1) and (3), you are in possession of a good reason for thinking that the hat is indeed blue. So you are in possession of a good reason for thinking that the belief in question (H) is true.

Like Explanatory Coherentism, this view faces a circularity problem also. If (H) receives its justification in part because you also believe (3), then (3) itself must be justified. But where would the justification for (3) come from?

One answer is: from one’s memory of perceptual success in the past. You remember that your experiences in the past have had a good track record of corresponding with reality, and they have rarely led you astray. The problem here is that you cannot justifiably attribute a good track record to your perceptual faculties without using your perceptual faculties. So, if reliability coherentism is going to work, it would have to be legitimate to use a faculty for the very purpose of establishing the reliability of that faculty itself.

Both Explanatory Coherentism and Reliability Coherentism each face their own distinctive circularity problem. Moreover, since both are version of Doxastic Coherentism, they both face a further difficulty: How do people, under normal circumstances, really form beliefs like (1), (2), and (3):
1. I am having a visual experience: The hat looks blue to me.

2. My having the visual experience is a reason for assuming that the hat is blue.
3. Experience like the hat looking blue to me are reliable.

It could be objected therefore that these two version of Coherentism make excessive intellectual demands on ordinary subjects who are unlikely to have the background beliefs needed for justification. This objection could be avoided by stripping Coherentism of its Doxastic element. The result would be the following version of Coherentism, which results from rejecting the Epistemic conception of basicality.

[Petros Agapetos]

Dependence Coherentism
Whenever one is justified in believing a proposition p1, one’s justification for believing p1 depends on justification one has for believing some further propositions p2, p3, …pn.
An Explanatory Coherentist might say:
For you to be justified in believing (H), it’s not necessary that you actually believe (1) and (2). However, it is necessary you have justification for believing (1) and (2). It is your having justification for (1) and (2) that give you justification for believing (H).
A Reliability Coherentist might say:
To be justified in believing (H), you need not believe anything about the reliability of the belief’s origin. You must however have justification for (1) and (3).
Dependence Coherentism is a departure from the way Coherentism has typically been construed by its advocates. According to the typical construal of Coherentism, the view says that a given belief is justified, the subject must have further beliefs that constitute reasons for the give belief. Dependence Coherentism rejects this! According to it, justification need not come in the form of beliefs. It can come from introspective and memorial evidence that gives a subject justification for beliefs about either reliability or explanatory coherence. In fact, Dependence Coherentism allows for the possibility that a belief is justified, not by receiving any of its justification from other beliefs, but solely by suitable perceptual experiences and memory content.

Dependence Coherentism, or Compromise Position on Coherentism:
I. It allows for doxastic basicality
II. It does not allow for epistemic basicality
III. It is inconsistent with doxastic coherentism
IV. It qualifies as a version of Coherentism, namely Dependence Coherentism
Note that (III) follows from (I) and (IV) follows from (II).

An uncompromising foundationalist would reject dependence coherentism. A foundationalist of this kind views a basic belief that p as a belief whose justification does not depend on having any justification for believing another proposition q. Foundationalism of this sort could be called Independence Foundationalism, since it asserts that a basic belief’s justification is completely independent of having justification for any other beliefs.

The logic of the conflict between foundationalism and coherentism seems to suggest that ultimately the conflict between the two views boils down to that between Dependence Coherentism and Independence Foundationalism.


Why Foundationalism?
The main argument for Foundationalism is the regress argument. With regard to every justified belief B1, the question arises of where B1’s justification comes from. If B1 is not basic, it would have to come from another belief B2. But B2 can justify B1 if and only if B2 is justified itself. If B2 is basic, then the justificatory chain terminates with B2. Unless the ensuring regress terminates in a basic belief, we get two possibilities:

(i) The regress will loop back to B1.
(ii) The regress will continue at infinitum.

According to the regress argument, both these possibilities are unacceptable. Therefore, if there are in fact justified beliefs then there must be basic beliefs. This regress argument suffers from various weaknesses. First, we may wonder whether the alternative to foundationalism are really unacceptable. There are elaborate defenses for “Infinitism” as the correct solution to the regress argument. Nor should circularity be dismissed too quickly. The issue is not whether a simply argument of the form ‘p therefore p’ is acceptable, of course it is not. Rather, the issue is ultimately whether, in the attempt to show that truth in our faculties is reasonable, we may make use of the input our faculties deliver. Whether such circularity is unacceptable as a ‘p therefore p’ inference is an open question.

[Petros Agapetos]

The Ethics of Belief
Belief is a dispositional, affirmative attitude towards a proposition or state of affairs. To believe that ‘p’ is to take it that ‘p’ is true or to take it that the state of affairs described by the sentence ‘p’ obtains. Note that this does not mean that the subject explicitly believes the proposition that ‘p’ is true. The mere belief that ‘p’ does not require possession of the concept of ‘truth’, whereas the belief that ‘p’ is true does. It is widely agreed upon that the majority of our beliefs are not occurrent at any given time, and that belief comes in degrees of strength, confidence, or firmness. Representationalists regard beliefs as structures in the mind that represent the propositions they affirm, usually in something like a mental language. Dispositionalists regard beliefs as dispositions to act in certain ways in certain circumstances.

The central question in the debate is whether there are norms of some sort governing our habits of belief-formation, belief-maintenance, and belief-relinquishment. Is it ever or always morally wrong or epistemically irrational or practically imprudent to hold a belief on insufficient evidence. Is it ever or always morally right or epistemically rational or practically prudent to believe on the basis of sufficient evidence or to withhold belief in the perceived absence of it. Is it ever or always obligatory to seek out all available epistemic evidence for a belief? Are there some ways of obtaining evidence that are themselves immoral, irrational, imprudent?

Related questions have to do with the nature and structure of norms involved, if any, as well as the source of their authority. Are they instrumental norms grounded in contingent ends that we set for ourselves? Are they categorical in being grounded in ends, set for us by the very nature of our intellectual or moral capacities. Finally, assuming that there are norms of some sort governing belief-formation, what does that imply about the nature of belief? Is belief formation voluntary or under our control? If so, what sort of control is this? Is it coherent to talk of ethics of belief?

Clifford offers his principle of doxastic self-control and defends the principle that we are all obliged to have sufficient evidence for every one of our beliefs “It is wrong always, everywhere, and for anyone to believe anything on insufficient evidence”. Clifford’s other principle: “It is wrong always, everywhere, and for anyone, to ignore evidence that is relevant to his beliefs or to dismiss relevant evidence in a facile way.” There might be at least two kinds of diachronic obligations here: one governing how we form and hold beliefs over time, and the other governing how we relinquish or revise beliefs over time. If someone violates such a diachronic obligation by purposely avoiding the reading of books, etc, the life of that man is one long sin against mankind. Clifford is an iconic representative of a strict evidentialist position on the ethics of belief – we are obliged to form beliefs always and only on the basis of sufficient evidence that is in our possession.

Pragmatist followers recognize that we are positively obliged sometimes to form beliefs on insufficient evidence and that it would be a significant prudential, intellectual or even moral failure to do otherwise.

The Pragmatist Method:
Ø Lay out a series of strict conditions under which an option counts as ‘genuine’ and believing without sufficient evidence is permitted or required.
Ø Must be between ‘live’ hypotheses – hypotheses that are among the mind’s possibilities
Ø There must also be compelling evidence one way or the other, the option must be forced such that doing nothing also amounts to making a choice, and the option must concern a ‘momentous’ issue.
Ø In the absence of these conditions, revert to a broadly evidentialist picture.
There are situations where we can believe things even with insufficient evidence. These situations must fit certain criteria. There must be situations that:
Ø Cannot be decided on intellectual grounds (when rational decisions are not available)
Ø Have two live options (real possibilities, as opposed to dead possibilities that one would not consider)
Ø Are forced (you cannot choose neither option: ex. either you eat your breakfast or you do not)
Ø Are momentous (irreversible, significant, and unique, while trivial choices are reversible, insignificant, or not unique, all three are sufficient)

The choice to suspend a belief is also a choice. Therefore, our decision about belief will be forced, so long as we are comparing whether we should believe or lack that particular belief. Not having any beliefs about ‘p’ is not the same as accepting that ‘p’ is not true. We are often forced to make these kinds of live and momentous decisions without evidence. To leave an option open or to suspend judgment is just as much a decision as to pick one option of the other. However, it seems that such a decision will not have the same detrimental effects of forming a belief without justification. Since further investigation as opposed to unjustified action is the logical result of a lack of belief, it does not have the same negative effects that Clifford warned of, as that belief in something does. It may be a choice, but it is not as consequential when it’s wrong.

To form a belief about important matters without possessing sufficient evidence or to believe anything with a degree of firmness that is not proportioned to the strength of our evidence is to misuse our faculties. John Locke says “It is to transgress against our own light either to believe on insufficient evidence or to fail to proportion our degree of belief to the strength of the evidence,” and also “he that believes without having any reason for believing may be in love with his own fancies, but neither seeks truth as he ought to nor pays the obedience due to his maker, who would have him use those discerning Faculties he has given him, to keep him out of mistake and error.”

[Petros Agapetos]

Sources of Knowledge and Justification
Beliefs arise in people for a wide variety of causes including psychological factors such as desires, emotional needs, prejudice, biases of various kinds, etc. Obviously, if beliefs originate in sources like these, they don’t qualify as knowledge even if true. For true beliefs to count as knowledge it is necessary that they originate in sources we have good reason to consider reliable: these are perception, introspection, memory, reason, and testimony.

Perception
Our perceptual faculties are our five senses: sight, touch, hearing, smell, and taste. We must distinguish between an experience that can be classified as perceiving that p, which entails that p is true and a perceptual experience as perceptual seeming. The reason for making this distinction lies in the fact that perceptual experience is fallible, for the world may not always be as it appears to us in our perceptual experiences. We need therefore a way to referring to perceptual experiences in which p seems to be the case that allows for the possibility of p being false. That’s the role assigned to perceptual seemings. So, some perceptual seemings that p are cases of perceiving that p, others are not. When it looks to you that there is a cup of coffee on your desk and in fact there is then the two states coincide. If, however you hallucinate that there is a cup on the table, you have perceptual seeming that p without perceiving that p. One family of epistemological issues about perception arises when we concern ourselves with the psychological nature of the perceptual processes through which we acquire knowledge of external objects. According to direct realism, we can acquire such knowledge because we can directly perceive such objects so that what you perceive is the thing in itself. According to indirect realism, we acquire knowledge of external objects by virtue of perceiving something else, namely appearances of sense data. An indirect realist would say it is not the thing in itself that we perceive but a thing-like sense-datum or some such entity. Direct and Indirect Realists hold different views regarding the structure of perceptual knowledge. Indirect Realists would say that we acquire perceptual knowledge of external objects by virtue of perceiving sense-data that represent external objects. Sense-data, a species of mental states, enjoy a special status – we know directly what they are like. So, Indirect Realists think that when perceptual knowledge is foundational, it is knowledge of sense-data and other mental states. Knowledge of external objects is indirect and derived from our knowledge of sense data. The basic idea is that we have indirect knowledge of the external world because we can have foundational knowledge of our own mind.

Are Our Perceptual Faculties Reliable?
We take our perceptual faculties to be reliable. But how can we know that they are reliable? For externalists, this might not be much of a challenge. If the use of reliable faculties is sufficient for knowledge, and if by using reliable faculties we acquire the belief that our faculties are reliable, then we come to know that our faculties are reliable. But even externalists might wonder how they can, via argument, show that our perceptual faculties are reliable. The problem is this. It would seem the only way of acquiring knowledge about the reliability of our perceptual faculties is through memory, through remembering whether they served us well in the past. But should I trust my memory, and should I think that the episodes of perceptual success that I seem to recall were in fact episodes of perceptual success? If I am entitled to answer these questions with ‘yes', then I need to have, to begin with, reason to view my memory and my perceptual experiences as reliable. It would seem, therefore, that there is no non-circular way of arguing for the reliability of one's perceptual faculties.

Introspection
Introspection is the capacity to inspect the, metaphorically speaking, “inside” of one’s mind. Through introspection, one knows what mental states one is in. Compared with perception, introspection appears to have a special status. It is easy to see how a perceptual seeming can go wrong. Could it be possible that it introspectively seems to me that I have a headache when in fact I do not? It is not easy to see how it could be. Thus compared to perception, introspection seems to be privileged by virtue of it being less prone to error. How can we account for the special status of introspection?

First, it could be argued that when it comes to introspection, there is no difference between appearance and reality. Therefore, introspective seemings are necessarily successful introspections. According to this approach introspection is infallible.

Alternatively, one could view introspection as a source of certainty. Here the idea is that an introspective experience of p eliminates all possible doubt as to whether p is true.

Finally, one could attempt to explain the special status of introspection by examining the way we respond to first person reports: typically, we attribute a special authority to such reports. According to this approach, introspection is incorrigible. Others are not (or at least not typically) in a position to correct first person reports of one’s own mental states.

Introspection reveals how the world appears to us in our perceptual experiences. For that reason, introspection has been a special interest to foundationalists.

Perception is not immune to error. If certainty consists in the absence of all possible doubt, then perception fails to yield certainty. Hence beliefs based on perceptual experiences cannot be foundational. Introspection however might deliver what we need to find a firm foundation for our beliefs about external objects: at best outright immunity to error or all possible doubt, or perhaps more modestly an epistemic kind of directness that cannot be found in perception.

Memory
Memory is the capacity to retain knowledge acquired in the past. What one remembers though need not be a past event. Memory is of course fallible. Not every instance of taking oneself to remember that p is an instance of actually remembering that p. We should distinguish therefore between remembering that p (which entails the truth that p) and seeming to remember p (which does not entail the truth that p).

One issue about memory concerns the question of what distinguishes memorial seemings from perceptual seemings or mere imagination. The distinctively epistemological questions about memory are these: First, what makes memorial seemings a source of justification? Is it a necessary truth that, if one has a memorial seeming that p, one has thereby prima facie justification for p? Or is memory a source of justification only if, as coherentists might say, one has reason to think that one's memory is reliable? Or is memory a source of justification only if, as externalists would say, it is in fact reliable? Second, how can we respond to skepticism about knowledge of the past? Memorial seemings of the past do not guarantee that the past is what we take it to be. We think that we are a bit older than just five minutes, but it is logically possible that the world sprang into existence just five minutes ago, complete with our dispositions to have memorial seemings of a more distant past and items such as apparent fossils that suggest a past going back millions of years. Our seeming to remember that the world is older than a mere five minutes does not entail, therefore, that it really is. Why, then, should we think that memory is a source of knowledge about the past?

Reason
Some beliefs would appear to be justified solely by the use of reason. Justification of that kind is said to be a priori: prior to any kind of experience. A standard way of defining a priori justification goes as follows:

A Priori Justification
S is justified a priori in believing that p if and only if S's justification for believing that p does not depend on any experience. Beliefs that are true and justified in this way (and not somehow "Gettiered") would count as instances of a priori knowledge.

What exactly counts as experience? If by ‘experience’ we mean just perceptual experiences, justification deriving from introspective or memorial experiences would count as a priori. For example, I could then know a priori that I'm thirsty, or what I ate for breakfast this morning. While the term ‘a priori’ is sometimes used in this way, the strict use of the term restricts a priori justification to justification derived solely from the use of reason. According to this usage, the word ‘experiences' in the definition above includes perceptual, introspective, and memorial experiences alike. On this narrower understanding, paradigm examples of what I can know on the basis of a priori justification are conceptual truths (such as "All bachelors are unmarried"), and truths of mathematics, geometry and logic.

Justification and knowledge that is not a priori is called ‘a posteriori’ or ‘empirical’. For example, in the narrow sense of ‘a priori’, whether I'm thirsty or not is something I know empirically (on the basis of introspective experiences), whereas I know a priori that 12 divided by 3 is 4.

Several important issues arise about a priori knowledge. First, does it exist at all? Skeptics about apriority deny its existence. They don't mean to say that we have no knowledge of mathematics, geometry, logic, and conceptual truths. Rather, what they claim is that all such knowledge is empirical.

Second, if a priori justification is possible, exactly how does it come about? What makes a belief such as "All bachelors are unmarried" justified solely on the basis of reason? Is it an unmediated grasp of the truth of this proposition? Or does it consist of grasping that the proposition is necessarily true? Or is it the purely intellectual experience of "seeing" (with the "eye of reason") or "intuiting" that this proposition is true (or necessarily true)? Or is it, as externalists would suggest, the reliability of the cognitive process by which we come to recognize the truth of such a proposition?

Third, if a priori knowledge exists, what is its extent? Empiricists have argued that a priori knowledge is limited to the realm of the analytic, consisting of propositions of a somehow inferior status because they are not really "about the world". Propositions of a superior status, which convey genuine information about world, are labeled synthetic. a priori knowledge of synthetic propositions, empiricists would say, is not possible. Rationalists deny this. They would say that a proposition such as "If a ball is green all over, then it doesn't have black spots" is synthetic and knowable a priori.

A fourth question about the nature of a priori knowledge concerns the distinction between necessary and contingent truths. The received view is that whatever is known a priori is necessarily true, but there are epistemologists who disagree with that.

Testimony
Testimony differs from the sources we considered above because it isn't distinguished by having its own cognitive faculty. Rather, to acquire knowledge of p through testimony is to come to know that p on the basis of someone's saying that p. "Saying that p" must be understood broadly, as including ordinary utterances in daily life, postings by bloggers on their web-logs, articles by journalists, delivery of information on television, radio, tapes, books, and other media. So, when you ask the person next to you what time it is, and she tells you, and you thereby come to know what time it is, that's an example of coming to know something on the basis of testimony.

The epistemological puzzle testimony raises is this: Why is testimony a source of knowledge? An externalist might say that testimony is a source of knowledge if and only if it comes from a reliable source. But here, even more so than in the case of our faculties, internalists will not find that answer satisfactory. Suppose you hear someone saying ‘p’. Suppose further that person is in fact utterly reliable with regard to the question of whether p is the case or not. Finally, suppose you have no evidential clue whatever as to that person's reliability. Wouldn't it be plausible to conclude that, since that person's reliability is unknown to you, that person's saying ‘p’ does not put you in a position to know that p? But if the reliability of a testimonial source is not sufficient for making it a source of knowledge, what else is needed? Thomas Reid suggested that, by our very nature, we accept testimonial sources as reliable and tend to attribute credibility to them unless we encounter special contrary reasons. But that's merely a statement of the attitude we in fact take toward testimony. What is it that makes that attitude reasonable? It could be argued that, in one's own personal experiences with testimonial sources, one has accumulated a long track record that can be taken as a sign of reliability. However, when we think of the sheer breadth of the knowledge we derive from testimony, one wonders whether one's personal experiences constitute some evidence base rich enough to justify the attribution of reliability to the totality of the testimonial sources one tends to trust. An alternative to the track record approach would be to declare it a necessary truth that trust in testimonial sources is justified. This suggestion, alas, encounters the same difficulty as the externalist approach to testimony: it does not seem we can acquire knowledge from sources the reliability of which is utterly unknown to us.

[LeBrok]

Quite extensive writing Petros, tremendous job you did. I don't have time at the moment to go through all of this, though I love philosophy. Or perhaps it is a sign of a little problem. Your writing being too much, too long and too complicated. Perhaps, you should try explaining your point of view with basic definitions and simple language. I'm guessing that at the moment only few people will understand your writing or will want to learn needed vocabulary and concepts and go through it.

How about something simple like this: Belief is ability to imagine things as real or not. To believe is to evaluate a real world in one's mind as True or False. We believe that things exist or not in now, past and future.

Simple example of belief in nature:
Hunters go hunting. They imagine that there is a prey out their and that they will catch it and feed whole tribe. Without believing in existence of prey, successful hunting and a future meal they wouldn't move a finger all day. They believe that these things are real and will come true.

Belief is essential part of thinking for humans and all animals with advanced cognitive system. When I hide a ball, my dog looks for it even if he can't see it, touch it, or smell it. He must believe in ball's existence in a real world in order to look for it. If he were unable to believe, once the ball is hidden from his senses, it would be gone from his world as well. It would stop existing for him (in his mind). No belief = non existence of hidden objects.
This phenomenon of "no see = no exist" is observable in infants. Hide a toy from infant's view and infant immediately stops looking for it. It doesn't wait for it to reappear either and goes instantly to other visual interest. The toy is gone, so it doesn't exist. Infants don't have concept of belief yet.



Imagination - everything that we "see" in our mind, except current input from our senses. For example thinking about buying a new lamp in the future is Imagination. Seeing existing lamp on my desk is not.

Belief - Imagining that things are real or not. To evaluate that things are real or not. Belief is part of Imagination, an organization system of our Imagination. Like Imagination is not used on things that we see now. (Or maybe it does, because sometimes "we can't believe our eyes")

[LeBrok]

Theories of Knowledge
Knowledge can be categorized as 1. Propositional knowledge (knowledge-that), 2. Knowledge by acquaintance (familiarity), and 3. Procedural Knowledge (ability knowledge, knowledge-how). Knowledge requires true beliefs because knowledge is a success term (successfully corresponds to reality). Knowledge involves acquisition of truth. There may be many ways of defending truth claims, but only really one proper way to define them, through correspondence to reality.

Isn't Knowledge all we can remember from our life? Every experience in our life can teach us something, therefore classified as knowledge.

[LeBrok]

Sources of Knowledge and Justification
Beliefs arise in people for a wide variety of causes including psychological factors such as desires, emotional needs, prejudice, biases of various kinds, etc. Obviously, if beliefs originate in sources like these, they don’t qualify as knowledge even if true. For true beliefs to count as knowledge it is necessary that they originate in sources we have good reason to consider reliable: these are perception, introspection, memory, reason, and testimony.

Kids love to believe in Santa Claus. Although existence of real Santa with supernatural powers is not true, kids learn that when parents say Santa is coming tonight, there will be presents tomorrow. It is Knowledge.
Later when kids find out that Santa is not real, they learn that parents do lie on occasion and not all people say (parents, people, TV) is not true. So even if Santa person is not real, it does teach us a lot. Knowledge.
There are many lessons and knowledge in fictional (not true) folk stories and legends. Don't go to forest alone, avoid strangers or listen to parents.
Hypothetical scenarios that we run in our heads, make believe stuff, has a function of helping us finding solutions or getting ready for future events.
There are probably very few examples in our memory that can't teach us something.

There is a very interesting connection between learning of knowledge and beliefs. We all, as little kids, learned most about the world from our parents. This is without leaving our home and yard, to see the world by ourselves. All this learning happens with help of belief system. We unconditionally believed our parents that what they say was the truth. Doesn't matter if it was a lie about Santa, or a truth that monkeys live in a jungle. We are born very gullible, very trustworthy. It is for a very good reason, from evolutionary point of view. It is much safer for offspring to learn knowledge from parents, than to go out and experiment by yourself losing a limb or own life in a process. But for that reason, we have to unconditionally trust and believe our parents and teachers.
However, as beneficial as it is, this obviously sets us up for a trap on many occasions. We believe in Santa as kids, we believe in god of our parents as adults.

[Petros Agapetos]

Here is an article from the IronChariots Wiki site about belief.
It is like a skeptic's encyclopedia of important terms used in religion.

Belief or believing, in simplest terms, is the acceptance by the mind of something as true. A belief is something which is believed. One can believe something to be true without having knowledge that it is true. Also, one can believe something to varying degrees of certainty (see also Probability).
Calling someone a believer often connotes belief in a god, especially the Christian God (in the U.S., anyway). There are many reasons people give for their belief in their god/s. Some amount to, “When I go outside and I look around I can only think god did it all.” Sometimes, though, the belief is related to some other supernatural or unsupported claim, such as ESP or alien abduction — or even to a philosophical position or political opinion.


Degrees of belief

Common phrases describing one's own degree of belief:

• I know that
• I believe that
• I think that
• I feel that
• I [would] guess that
• I [would] bet/wager that
• I [would] like to think/believe that
• I have no reason to doubt that
• I have no reason not to believe/think that

Common phrases describing the degree of believability of a statement of fact:

• It is true
• It is certainly true
• It is surely true
• It is almost certainly/surely true
• It is most likely true
• It is likely true
• It is probably true
• It is possibly true
• It is perhaps true
• It may be true
• It might be true
• It should be true
• It can/could be true

In addition, most of the above statements could be negated in two different ways, giving rise to different connotations. For example, "It is not likely true" is different from "It is likely not true".

[Petros Agapetos]

Disbelief

The word disbelief has two possible connotations:

1. lack of, or absence of, belief
2. belief to the contrary

The two connotations are at the heart of the confusion between weak atheism (lack of belief in any gods) and strong atheism (positive belief that there are no gods).
See also Atheist vs. agnostic and Absolute certainty.

Belief vs. faith
Faith is sometimes defined as belief without evidence, or in the face of contradictory evidence. Clearly, "belief" does not always imply "faith," as one can believe something based on evidence or for other rational reasons (e.g., logical arguments). For example, one does not need to have faith that the sun will rise tomorrow, since the fact that the sun rises every day is supported by a lifetime of personal experience, thousands of years worth of recorded observations, and a scientific model of the earth's rotation on an axis.

Belief in
However, the definition of "faith" given above is usually not what religious people mean when they use the word: to them, having faith is closer to "trusting" than simply "believing" (see the Faith article for more information). The phrase "belief in" is sometimes used to imply this element of trust. For example, when Christians say they "believe in" God, they usually don't simply mean that they believe he exists, but that they believe he loves them, has a plan for their lives, will see them through hard times, etc. For this reason, when Christians ask what atheists "believe in", or whether an atheist "believes in" evolution or the big bang, the best response is likely to include an explanation of the difference between belief and faith.

Philosophically

• How do we define belief and believing? If
  
  • A: Belief is a form of reason and reason denotes structure, then belief equals our awareness of the world through a structured combination of sensory input.
    
    • AA: Then the structure with the highest amount of order and inner coherence would be the most true. All closed logical speculations have a higher amount of truth then open and random speculations.
      
      • AB: If in theory no human mind can exist inside a closed logical mode, then all logical speculations must be inherently open, and open to random speculations. And the validity of these random speculations would only be laid down by the structured and organised mind mimicking a closed logical speculation system (dogma), then believe is always dogma and freedom is inclusion of all forms even if they contradict each other.
    
    
  • B: Belief is a lack of reason and would not denote structure but rather randomness projected on a structured consciousness.
    
    • BB: This would define all believe as raw sensory input and lead back to point A.

[Petros Agapetos]

Knowledge is traditionally defined as "justified true belief"

Nailing down which beliefs really count as knowledge is sometimes tricky and requires a lot of qualifiers.
Consider a factual claim X, such as "The moon is made of green cheese." If I say that I "know" X is true, we may assume from that I also "believe" that X is true (unless I am lying or deluded about my own beliefs, which is rare). However, my statement is wrong in two ways. First, X is false (the moon is not made of green cheese), so I am factually incorrect about my belief. Second, I cannot truly be said to know X, because one can only know a true statement.

However, even if one believes something that happens to be true, this isn't necessarily knowledge. Suppose you walk onto a crowded subway, and you pick out a stranger from the crowd, and you tell yourself: "I believe that his name is John Smith." Now let us further suppose that the stranger happens to actually be named John Smith. This is purely coincidental, because John Smith happens to be a common name and you had no way of knowing what the stranger's name was. The question is, did you really "know" that his name was John Smith?

Philosophers would say no. Even a true belief cannot be properly termed "knowledge" unless there is a good reason to believe the statement. This is why the word "justified" is included in the definition.