Epistemology

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epistemology (from Greek episteme, ‘knowledge’, and logos, ‘explanation’)Go to Topic Page
The study of the nature of knowledge and justification; specifically, the study of (a) the defining features, (b) the substantive conditions or sources, and (c) the limits of knowledge and justification. The latter three categories are represented by traditional philosophical controversy over the analysis of knowledge and justification, the sources of knowledge and justification (e.g., rationalism versus empiricism), and the viability of skepticism about knowledge and justification.


Kinds of knowledge
Knowledge can be either explicit or tacit. Explicit knowledge is self-conscious in that the knower is aware of the relevant state of knowledge, whereas tacit knowledge is implicit, hidden from self-consciousness. Much of our knowledge is tacit: it is genuine but we are unaware of the relevant states of knowledge, even if we can achieve awareness upon suitable reflection. In this regard, knowledge resembles many of our psychological states. The existence of a psychological state in a person does not require the person’s awareness of that state, although it may require the person’s awareness of an object of that state (such as what is sensed or perceived).

Philosophers have identified various species of knowledge: for example, propositional knowledge (that something is so), non-propositional knowledge of something (e.g., knowledge by acquaintance, or by direct awareness), empirical (a posteriori) propositional knowledge, nonempirical (a priori) propositional knowledge, and knowledge of how to do something. Philosophical controversy has arisen over distinctions between such species, for example, over (i) the relations between some of these species (e.g., does knowing-how reduce to knowledge-that?), and (ii) the viability of some of these species (e.g., is there really such a thing as, or even a coherent notion of, a priori knowledge?). A primary concern of classical modern philosophy, in the seventeenth and eighteenth centuries, was the extent of our a priori knowledge relative to the extent of our a posteriori knowledge. Such rationalists as Descartes, Leibniz, and Spinoza contended that all genuine knowledge of the real world is a priori, whereas such empiricists as Locke, Berkeley, and Hume argued that all such knowledge is a posteriori. In his Critique of Pure Reason (1781), Kant sought a grand reconciliation, aiming to preserve the key lessons of both rationalism and empiricism.

Since the seventeenth and eighteenth centuries, a posteriori knowledge has been widely regarded as knowledge that depends for its supporting ground on some specific sensory or perceptual experience; and a priori knowledge has been widely regarded as knowledge that does not depend for its supporting ground on such experience. Kant and others have held that the supporting ground for a priori knowledge comes solely from purely intellectual processes called “pure reason” or “pure understanding.” Knowledge of logical and mathematical truths typically serves as a standard case of a priori knowledge, whereas knowledge of the existence or presence of physical objects typically serves as a standard case of a posteriori knowledge. A major task for an account of a priori knowledge is the explanation of what the relevant purely intellectual processes are, and of how they contribute to non-empirical knowledge. An analogous task for an account of a posteriori knowledge is the explanation of what sensory or perceptual experience is and how it contributes to empirical knowledge. More fundamentally, epistemologists have sought an account of propositional knowledge in general, i.e., an account of what is common to a priori and a posteriori knowledge.

Ever since Plato’s Meno and Theaetetus (c.400 B.C.), epistemologists have tried to identify the essential, defining components of knowledge. Identifying these components will yield an analysis of knowledge. A prominent traditional view, suggested by Plato and Kant among others, is that propositional knowledge (that something is so) has three individually necessary and jointly sufficient components: justification, truth, and belief. On this view, propositional knowledge is, by definition, justified true belief. This is the tripartite definition that has come to be called the standard analysis. We can clarify it by attending briefly to each of its three conditions.


The belief condition
This requires that anyone who knows that p (where ‘p’ stands for any proposition or statement) must believe that p. If, therefore, you do not believe that minds are brains (say, because you have not considered the matter at all), then you do not know that minds are brains. A knower must be psychologically related somehow to a proposition that is an object of knowledge for that knower. Proponents of the standard analysis hold that only belief can provide the needed psychological relation. Philosophers do not share a uniform account of belief, but some considerations supply common ground. Beliefs are not actions of assenting to a proposition; they rather are dispositional psychological states that can exist even when unmanifested. (You do not cease believing that 2 + 2 = 4, for example, whenever your attention leaves arithmetic.) Our believing that p seems to require that we have a tendency to assent to p in certain situations, but it seems also to be more than just such a tendency. What else believing requires remains highly controversial among philosophers.

Some philosophers have opposed the belief condition of the standard analysis on the ground that we can accept, or assent to, a known proposition without actually believing it. They contend that we can accept a proposition even if we fail to acquire a tendency, required by believing, to accept that proposition in certain situations. On this view, acceptance is a psychological act that does not entail any dispositional psychological state, and such acceptance is sufficient to relate a knower psychologically to a known proposition. However this view fares, one underlying assumption of the standard analysis seems correct: our concept of knowledge requires that a knower be psychologically related somehow to a known proposition. Barring that requirement, we shall be hard put to explain how knowers psychologically posses their knowledge of known propositions.

Even if knowledge requires belief, belief that p does not require knowledge that p, since belief can typically be false. This observation, familiar from Plato’s Theaetetus, assumes that knowledge has a truth condition. On the standard analysis, if you know that p, then it is true that p. If, therefore, it is false that minds are brains, then you do not know that minds are brains. It is thus misleading to say, e.g., that astronomers before Copernicus knew that the earth is flat; at best, they justifiably believed that they knew this.


The truth condition
This condition of the standard analysis has not attracted any serious challenge. Controversy over it has focused instead on Pilate’s vexing question: What is truth? This question concerns what truth consists in, not our ways of finding out what is true. Influential answers come from at least three approaches: truth as correspondence (i.e., agreement, of some specified sort, between a proposition and an actual situation); truth as coherence (i.e., interconnectedness of a proposition with a specified system of propositions); and truth as pragmatic cognitive value (i.e., usefulness of a proposition in achieving certain intellectual goals). Without assessing these prominent approaches, we should recognize, in accord with the standard analysis, that our concept of knowledge seems to have a factual requirement: we genuinely know that p only if it is the case that p. The pertinent notion of “its being the case” seems equivalent to the notion of “how reality is” or “how things really are.” The latter notion seems essential to our notion of knowledge, but is open to controversy over its explication.


The justification condition
Knowledge is not simply true belief. Some true beliefs are supported only by lucky guesswork and hence do not qualify as knowledge. Knowledge requires that the satisfaction of its belief condition be “appropriately related” to the satisfaction of its truth condition. This is one broad way of understanding the justification condition of the standard analysis. More specifically, we might say that a knower must have adequate indication that a known proposition is true. If we understand such adequate indication as a sort of evidence indicating that a proposition is true, we have reached the traditional general view of the justification condition: justification as evidence. Questions about justification attract the lion’s share of attention in contemporary epistemology. Controversy focuses on the meaning of ‘justification’as well as on the substantive conditions for a belief’s being justified in a way appropriate to knowledge.

Current debates about the meaning of ‘justification’revolve around the question whether, and if so how, the concept of epistemic (knowledge-relevant) justification is normative. Since the 1950s Chisholm has defended the following deontological (obligation-oriented) notion of justification: the claim that a proposition, p, is epistemically justified for you means that it is false that you ought to refrain from accepting p. In other terms, to say that p is epistemically justified is to say that accepting p is epistemically permissible—at least in the sense that accepting p is consistent with a certain set of epistemic rules. This deontological construal enjoys wide representation in contemporary epistemology. A normative construal of justification need not be deontological;it need not use the notions of obligation and permission. Alston, for instance, has introduced a non-deontological normative concept of justification that relies mainly on the notion of what is epistemically good from the viewpoint of maximizing truth and minimizing falsity. Alston links epistemic goodness to a belief’s being based on adequate grounds in the absence of overriding reasons to the contrary.

Some epistemologists shun normative construals of justification as superfluous. One noteworthy view is that ‘epistemic justification’means simply ‘evidential support’ of a certain sort. To say that p is epistemically justifiable to some extent for you is, on this view, just to say that p is supportable to some extent by your overall evidential reasons. This construal will be non-normative so long as the notions of supportability and an evidential reason are non-normative. Some philosophers have tried to explicate the latter notions without relying on talk of epistemic permissibility or epistemic goodness. We can understand the relevant notion of “support” in terms of non-normative notions of entailment and explanation (or, answering why-questions). We can understand the notion of an “evidential reason” via the notion of a psychological state that can stand in a certain truth-indicating support relation to propositions. For instance, we might regard non-doxastic states of “seeming to perceive” something (e.g., seeming to see a dictionary here) as foundational truth indicators for certain physical-object propositions (e.g., the proposition that there is a dictionary here), in virtue of those states being best explained by those propositions. If anything resembling this approach succeeds, we can get by without the aforementioned normative notions of epistemic justification.


Foundationalism versus coherentism
Talk of foundational truth indicators brings us to a key controversy over justification: Does epistemic justification, and thus knowledge, have foundations, and if so, in what sense? This question can be clarified as the issue whether some beliefs can not only (a) have their epistemic justification non-inferentially (i.e., apart from evidential support from any other beliefs), but also (b) provide epistemic justification for all justified beliefs that lack such non-inferential justification. Foundationalism gives an affirmative answer to this issue, and is represented in varying ways by, e.g., Aristotle, Descartes, Russell, C.I. Lewis, and Chisholm.

Foundationalists do not share a uniform account of non-inferential justification. Some construe non-inferential justification as self-justification. Others reject literal self-justification for beliefs, and argue that foundational beliefs have their non-inferential justification in virtue of evidential support from the deliverances of non-belief psychological states, e.g., perception (“seem-ing-to-perceive” states), sensation (“seeming-to-sense”states), or memory (“seeming-to-remember”states). Still others understand non-inferential justification in terms of a belief’s being “reliably produced,” i.e., caused and sustained by some non-belief belief-producing process or source (e.g., perception, memory, introspection) that tends to produce true rather than false beliefs. This last view takes the causal source of a belief to be crucial to its justification. Unlike Descartes, contemporary foundationalists clearly separate claims to non-inferential, foundational justification from claims to certainty. They typically settle for a modest foundationalism implying that foundational beliefs need not be indubitable or infallible. This contrasts with the radical foundationalism of Descartes.

The traditional competitor to foundationalism is the coherence theory of justification, i.e., epistemic coherentism. This is not the coherence definition of truth; it rather is the view that the justification of any belief depends on that belief’s having evidential support from some other belief via coherence relations such as entailment or explanatory relations. Notable proponents include Hegel, Bosanquet, and Sellars. A prominent contemporary version of epistemic coherentism states that evidential coherence relations among beliefs are typically explanatory relations. The rough idea is that a belief is justified for you so long as it either best explains, or is best explained by, some member of the system of beliefs that has maximal explanatory power for you. Contemporary coherentism is uniformly systemic or holistic; it finds the ultimate source of justification in a system of interconnected beliefs or potential beliefs.

One problem has troubled all versions of coherentism that aim to explain empirical justification: the isolation argument. According to this argument, coherentism entails that you can be epistemically justified in accepting an empirical proposition that is incompatible with, or at least improbable given, your total empirical evidence. The key assumption of this argument is that your total empirical evidence includes non-belief sensory and perceptual awareness-states, such as your feeling pain or your seeming to see something. These are not belief-states. Epistemic coherentism, by definition, makes justification a function solely of coherence relations between propositions, such as propositions one believes or accepts. Thus, such coherentism seems to isolate justification from the evidential import of non-belief awareness-states. Coherentists have tried to handle this problem, but no resolution enjoys wide acceptance.


Causal and contextualist theories
Some contemporary epistemologists endorse contextualism regarding epistemic justification, a view suggested by Dewey, Wittgenstein, and Kuhn, among others. On this view, all justified beliefs depend for their evidential support on some unjustified beliefs that need no justification. In any context of inquiry, people simply assume (the acceptability of) some propositions as starting points for inquiry, and these “contextually basic” propositions, though lacking evidential support, can serve as evidential support for other propositions. Contextualists stress that contextually basic propositions can vary from context to context (e.g., from theological inquiry to biological inquiry) and from social group to social group. The main problem for contextualists comes from their view that unjustified assumptions can provide epistemic justification for other propositions. We need a precise explanation of how an unjustified assumption can yield evidential support, how a non-probable belief can make another belief probable. Contextualists have not given a uniform explanation here.

Recently some epistemologists have recommended that we give up the traditional evidence condition for knowledge. They recommend that we construe the justification condition as a causal condition. Roughly, the idea is that you know that p if and only if (a) you believe that p, (b) p is true, and (c) your believing that p is causally produced and sustained by the fact that makes p true. This is the basis of the causal theory of knowing, which comes with varying details. Any such causal theory faces serious problems from our knowledge of universal propositions. Evidently, we know, for instance, that all dictionaries are produced by people, but our believing that this is so seems not to be causally supported by the fact that all dictionaries are humanly produced. It is not clear that the latter fact causally produces any beliefs.

Another problem is that causal theories typically neglect what seems to be crucial to any account of the justification condition: the requirement that justificational support for a belief be accessible, in some sense, to the believer. The rough idea is that one must be able to access, or bring to awareness, the justification underlying one’s beliefs. The causal origins of a belief are, of course, often very complex and inaccessible to a believer. Causal theories thus face problems from an accessibility requirement on justification. Internalism regarding justification preserves an accessibility requirement on what confers justification, whereas epistemic externalism rejects this requirement. Debates over internalism and externalism abound in current epistemology, but internalists do not yet share a uniform detailed account of accessibility.


The Gettier problem
The standard analysis of knowledge, however elaborated, faces a devastating challenge that initially gave rise to causal theories of knowledge: the Gettier problem. In 1963 Edmund Gettier published a highly influential challenge to the view that if you have a justified true belief that p, then you know that p. Here is one of Gettier’s counterexamples to this view: Smith is justified in believing the false proposition that (i) Jones owns a Ford. On the basis of (i), Smith infers, and thus is justified in believing, that (ii) either Jones owns a Ford or Brown is in Barcelona. As it happens, Brown is in Barcelona, and so (ii) is true. So, although Smith is justified in believing the true proposition (ii), Smith does not know (ii).

Gettier-style counterexamples are cases where a person has justified true belief that p but lacks knowledge that p. The Gettier problem is the problem of finding a modification of, or an alternative to, the standard analysis that avoids difficulties from Gettier-style counterexamples. The controversy over the Gettier problem is highly complex and still unsettled. Many epistemologists take the lesson of Gettier-style counterexamples to be that propositional knowledge requires a fourth condition, beyond the justification, truth, and belief conditions. No specific fourth condition has received overwhelming acceptance, but some proposals have become prominent. The so-called defeasibility condition, e.g., requires that the justification appropriate to knowledge be “undefeated” in the general sense that some appropriate subjunctive conditional concerning defeaters of justification be true of that justification. For instance, one simple defeasibility fourth condition requires of Smith’s knowing that p that there be no true proposition, q, such that if q became justified for Smith, p would no longer be justified for Smith. So if Smith knows, on the basis of his visual perception, that Mary removed books from the library, then Smith’s coming to believe the true proposition that Mary’s identical twin removed books from the library would not undermine the justification for Smith’s belief concerning Mary herself. A different approach shuns subjunctive conditionals of that sort, and contends that propositional knowledge requires justified true belief that is sustained by the collective totality of actual truths. This approach requires a detailed account of when justification is undermined and restored.

The Gettier problem is epistemologically important. One branch of epistemology seeks a precise understanding of the nature (e.g., the essential components) of propositional knowledge. Our having a precise understanding of propositional knowledge requires our having a Gettier-proof analysis of such knowledge. Epistemologists thus need a defensible solution to the Gettier problem, however complex that solution is.


Skepticism
Epistemologists debate the limits, or scope, of knowledge. The more restricted we take the limits of knowledge to be, the more skeptical we are. Two influential types of skepticism are knowledge skepticism and justification skepticism. Unrestricted knowledge skepticism implies that no one knows anything, whereas unrestricted justification skepticism implies the more extreme view that no one is even justified in believing anything. Some forms of skepticism are stronger than others. Knowledge skepticism in its strongest form implies that it is impossible for anyone to know anything. A weaker form would deny the actuality of our having knowledge, but leave open its possibility. Many skeptics have restricted their skepticism to a particular domain of supposed knowledge: e.g., knowledge of the external world, knowledge of other minds, knowledge of the past or the future, or knowledge of unperceived items. Such limited skepticism is more common than unrestricted skepticism in the history of epistemology.

Arguments supporting skepticism come in many forms. One of the most difficult is the problem of the criterion, a version of which has been stated by the sixteenth-century skeptic Montaigne: “To adjudicate [between the true and the false] among the appearances of things, we need to have a distinguishing method; to validate this method, we need to have a justifying argument;but to validate this justifying argument, we need the very method at issue. And there we are, going round on the wheel.” This line of skeptical argument originated in ancient Greece, with epistemology itself. It forces us to face this question: How can we specify what we know without having specified how we know, and how can we specify how we know without having specified what we know? Is there any reasonable way out of this threatening circle? This is one of the most difficult epistemological problems, and a cogent epistemology must offer a defensible solution to it. Contemporary epistemology still lacks a widely accepted reply to this urgent problem.

See also a priori, coherentism, foundationalism, justification, perception, Skepticism, truth. P.K.M.

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Epistemology. (1999). In Robert Audi (Ed.), The Cambridge dictionary of philosophy. Retrieved from http://ezproxy.rowan.edu/login?url=http://search.credoreference.com/content/entry/cupdphil/epistemology/0

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