The Analysis of Knowledge
For any person, there are some things they know, and some things they dont. What exactly is the difference? What does it take to know something? Its not enough just to believe itwe dont know the things were wrong about. Knowledge seems to be more like a way of getting at the truth. The analysis of knowledge concerns the attempt to articulate in what exactly this kind of getting at the truth consists.
More particularly, the project of analysing knowledge is to state conditions that are individually necessary and jointly sufficient for propositional knowledge, thoroughly answering the question, what does it take to know something? By propositional knowledge, we mean knowledge of a propositionfor example, if Susan knows that Alyssa is a musician, she has knowledge of the proposition that Alyssa is a musician. Propositional knowledge should be distinguished from knowledge of acquaintance, as obtains when Susan knows Alyssa. The relation between propositional knowledge and the knowledge at issue in other knowledge locutions in English, such as knowledge-where (Susan knows where she is) and especially knowledge-how (Susan knows how to ride a bicycle) is subject to some debate (see Stanley 2011 and his opponents discussed therein).
The propositional knowledge that is the analysandum of the analysis of knowledge literature is paradigmatically expressed in English by sentences of the form Sknows thatp, where S refers to the knowing subject, and p to the proposition that is known. A proposed analysis consists of a statement of the following form:Sknows thatpif and only ifj, wherejindicates the analysans: paradigmatically, a list of conditions that are individually necessary and jointly sufficient forSto have knowledge thatp.
It is not enough merely to pick out the actual extension of knowledge. Even if, in actual fact, all cases ofSknowing thatpare cases ofj, and all cases of the latter are cases of the former,jmight fail as an analysis of knowledge. For example, it might be that there arepossiblecases of knowledge withoutj, or vice versa. A proper analysis of knowledge should at least be a necessary truth. Consequently, hypothetical thought experiments provide appropriate test cases for various analyses, as we shall see below.
Even a necessary biconditional linking knowledge to some statejwould probably not be sufficient for an analysis of knowledge, although just what more is required is a matter of some controversy. According to some theorists, to analyze knowledge is literally to identify the components that make up knowledgecompare a chemist who analyzes a sample to learn its chemical composition. On this interpretation of the project of analyzing knowledge, the defender of a successful analysis of knowledge will be committed to something like the metaphysical claim thatwhat it isforSto knowpis for some list of conditions involvingSandpto obtain. Other theorists think of the analysis of knowledge as distinctivelyconceptualto analyse knowledge is to limn the structure of theconceptof knowledge. On one version of this approach, the conceptknowledgeis literally composed of more basic concepts, linked together by something like Boolean operators. Consequently, an analysis is subject not only to extensional accuracy, but to facts about the cognitive representation of knowledge and other epistemic notions. In practice, many epistemologists engaging in the project of analyzing knowledge leave these metaphilosophical interpretive questions unresolved; attempted analyses, and counterexamples thereto, are often proposed without its being made explicit whether the claims are intended as metaphysical or conceptual ones. In many cases, this lack of specificity may be legitimate, since all parties tend to agree that an analysis of knowledge oughtat leastto be extensionally correct in all metaphysically possible worlds. As we shall see, many theories have been defended and, especially, refuted, on those terms.
The attempt to analyze knowledge has received a considerable amount of attention from epistemologists, particularly in the late 20thCentury, but no analysis has been widely accepted. Some contemporary epistemologists reject the assumption that knowledge is susceptible to analysis.
There are three components to the traditional (tripartite) analysis of knowledge. According to this analysis, justified, true belief is necessary and sufficient for knowledge.
The tripartite analysis of knowledge is often abbreviated as the JTB analysis, for justified true belief.
Much of the twentieth-century literature on the analysis of knowledge took the JTB analysis as its starting-point. It became something of a convenient fiction to suppose that this analysis was widely accepted throughout much of the history of philosophy. In fact, however, the JTB analysis was first articulated in the twentieth century by its attackers.Before turning to influential twentieth-century arguments against the JTB theory, let us briefly consider the three traditional components of knowledge in turn.
Most epistemologists have found it overwhelmingly plausible that what is false cannot be known. For example, Hillary Clinton did not win the 2016 US Presidential election. Consequently, nobody knows that Hillary Clinton won the election. One can only know things that are true.
Sometimes when people are very confident of something that turns out to be wrong, we use the word knows to describe their situation. Many people expected Clinton to win the election. Speaking loosely, one might even say that many people knew that Clinton would win the electionuntil she lost. Hazlett (2010) argues on the basis of data like this that knows is not a factive verb.Hazletts diagnosis is deeply controversial; most epistemologists will treat sentences like I knew that Clinton was going to win as a kind of exaggerationas not literally true.
Somethings truth does not require that anyone can know or prove that it is true. Not all truths areestablishedtruths. If you flip a coin and never check how it landed, it may be true that it landed heads, even if nobody has any way to tell. Truth is ametaphysical, as opposed toepistemological, notion: truth is a matter of how thingsare, not how they can beshownto be. So when we say that only true things can be known, were not (yet) saying anything about how anyone canaccessthe truth. As well see, the other conditions have important roles to play here. Knowledge is a kind of relationship with the truthto know something is to have a certain kind of access to a fact.
The belief condition is only slightly more controversial than the truth condition. The general idea behind the belief condition is that you can only know what you believe. Failing to believe something precludes knowing it. Belief in the context of the JTB theory meansfullbelief, oroutrightbelief. In a weak sense, one might believe something by virtue of being pretty confident that its probably truein this weak sense, someone who considered Clinton the favourite to win the election, even while recognizing a nontrivial possibility of her losing, might be said to have believed that Clinton would win. Outright belief is stronger (see, e.g., Fantl & McGrath 2009: 141; Nagel 2010: 4134; Williamson 2005: 108; or Gibbons 2013: 201.). To believe outright thatp, it isnt enough to have a pretty high confidence inp; it is something closer to a commitment or a being sure.
Although initially it might seem obvious that knowing thatprequires believing thatp, a few philosophers have argued that knowledge without belief is indeed possible. Suppose Walter comes home after work to find out that his house has burned down. He says: I dont believe it. Critics of the belief condition might argue that Walter knows that his house has burned down (he sees that it has), but, as his words indicate, he does not believe it. The standard response is that Walters avowal of disbelief is not literally true; what Walter wishes to convey by saying I dont believe it is not that he really does not believe that his house has burned down, but rather that he finds it hard to come to terms with what he sees. If he genuinely didnt believe it, some of his subsequent actions, such as phoning his insurance company, would be rather mysterious.
A more serious counterexample has been suggested by Colin Radford (1966). Suppose Albert is quizzed on English history. One of the questions is: When did Queen Elizabeth die? Albert doesnt think he knows, but answers the question correctly. Moreover, he gives correct answers to many other questions to which he didnt think he knew the answer. Let us focus on Alberts answer to the question about Elizabeth:
Radford makes the following two claims about this example:
Radfords intuitions about cases like these do not seem to be idiosyncratic; Myers-Schutz & Schwitzgebel (2013) find evidence suggesting that many ordinary speakers tend to react in the way Radford suggests. In support of (a), Radford emphasizes that Albert thinks he doesnt know the answer to the question. He doesnt trust his answer because he takes it to be a mere guess. In support of (b), Radford argues that Alberts answer is not at all just a lucky guess. The fact that he answers most of the questions correctly indicates that he has actually learned, and never forgotten, such historical facts.
Since he takes (a) and (b) to be true, Radford holds that belief is not necessary for knowledge. But either of (a) and (b) might be resisted. One might deny (a), arguing that Albert does have atacitbelief that (E), even though its not one that he thinks amounts to knowledge. David Rose and Jonathan Schaffer (2013) take this route. Alternatively, one might deny (b), arguing that Alberts correct answer is not an expression of knowledge, perhaps because, given his subjective position, he does not have justification for believing (E). The justification condition is the topic of the next section.
Why is condition(iii)necessary? Why not say that knowledge is true belief? The standard answer is that to identify knowledge with true belief would be implausible because a belief might be true even though it is formed improperly. Suppose that William flips a coin, and confidently believeson no particular basisthat it will land tails. If by chance the coin does land tails, then Williams belief was true; but a lucky guess such as this one is no knowledge. For William to know, his belief must in some epistemic sense be proper or appropriate: it must bejustified.
Socrates articulates the need for something like a justification condition in PlatosTheaetetus, when he points out that true opinion is in general insufficient for knowledge. For example, if a lawyer employs sophistry to induce a jury into a belief that happens to be true, this belief is insufficiently well-grounded to constitute knowledge.
There is considerable disagreement among epistemologists concerning what the relevant sort of justification here consists in.Internalistsabout justification think that whether a belief is justified depends wholly on states in some senseinternalto the subject. According to one common such sense of internal, only those features of a subjects experience which are directly or introspectively available count as internalcall this access internalism. According to another, only intrinsic states of the subject are internalcall this state internalism. See Feldman & Conee 2001 for the distinction.
Conee and Feldman present an example of an internalist view. They have it thatSs belief thatpis justified if and only if believing thatpis the attitude towardspthat best fitsSs evidence, where the latter is understood to depend only onSs internal mental states. Conee and Feldman call their view evidentialism, and characterize this as the thesis that justification is wholly a matter of the subjects evidence. Given their (not unsubstantial) assumption that what evidence a subject has is an internal matter, evidentialism implies internalism.Externalistsabout justification think that factors external to the subject can be relevant for justification; for example, process reliabilists think that justified beliefs are those which are formed by a cognitive process which tends to produce a high proportion of true beliefs relative to false ones.We shall return to the question of how reliabilist approaches bear on the analysis of knowledge in6.1.
It is worth noting that one might distinguish between two importantly different notions of justification, standardly referred to as propositional justification and doxastic justification. (Sometimes ex ante justification and ex post justification, respectively.)Unlike that between internalist and externalist approaches to justification, the distinction between propositional and doxastic justification does not represent a conflict to be resolved; it is a distinction between two distinct properties that are called justification. Propositional justification concerns whether a subject has sufficient reason to believe a given proposition;doxastic justification concerns whether a given belief is held appropriately.One common way of relating the two is to suggest that propositional justification is the more fundamental, and that doxastic justification is a matter of a subjects having a belief that is appropriately responsive to or based on their propositional justification.
The precise relation between propositional and doxastic justification is subject to controversy, but it is uncontroversial that the two notions can come apart. Suppose that Ingrid ignores a great deal of excellent evidence indicating that a given neighborhood is dangerous, but superstitiously comes to believe that the neighborhood is dangerous when she sees a black cat crossing the street. Since forming beliefs on the basis of superstition is not an epistemically appropriate way of forming beliefs, Ingrids belief is not doxastically justified; nevertheless, shedoeshave good reason to believe as she does, so she does have propositional justification for the proposition that the neighborhood is dangerous.
Since knowledge is a particularly successful kind of belief, doxastic justification is a stronger candidate for being closely related to knowledge; the JTB theory is typically thought to invoke doxastic justification (but see Lowy 1978).
Some epistemologists have suggested that there may be multiple senses of the term knowledge, and that not all of them require all three elements of the tripartite theory of knowledge. For example, some have argued that there is, in addition to the sense of knowledge gestured at above, another,weaksense of knowledge, that requires only true belief (see for example Hawthorne 2002 and Goldman & Olsson 2009; the latter contains additional relevant references). This view is sometimes motivated by the thought that, when we consider whether someone knows thatp, or wonder which of a group of people know thatp, often, we are not at all interested in whether the relevant subjects have beliefs that are justified; we just want to know whether they have the true belief. For example, as Hawthorne (2002: 25354) points out, one might ask how many students know that Vienna is the capital of Austria; the correct answer, one might think, just is the number of students who offer Vienna as the answer to the corresponding question, irrespective of whether their beliefs are justified. Similarly, if you are planning a surprise party for Eugene and ask whether he knows about it, yes may be an appropriate answer merely on the grounds that Eugene believes that you are planning a party.
One could allow that there is a lightweight sense of knowledge that requires only true belief; another option is to decline to accept the intuitive sentences as true at face value. A theorist might, for instance, deny that sentences like Eugene knows that you are planning a party, or eighteen students know that Vienna is the capital of Austria are literally true in the envisaged situations, explaining away their apparent felicity as loose talk or hyperbole.
Even among those epistemologists who think that there is a lightweight sense of knows that does not require justification, most typically admit that there is also a stronger sense which does, and that it is this stronger state that is the main target of epistemological theorizing about knowledge. In what follows, we will set aside the lightweight sense, if indeed there be one, and focus on the stronger one.
Few contemporary epistemologists accept the adequacy of the JTB analysis. Although most agree that each element of the tripartite theory isnecessaryfor knowledge, they do not seem collectively to besufficient. There seem to be cases of justified true belief that still fall short of knowledge. Here is one kind of example:
Imagine that we are seeking water on a hot day. We suddenly see water, or so we think. In fact, we are not seeing water but a mirage, but when we reach the spot, we are lucky and find water right there under a rock. Can we say that we had genuine knowledge of water? The answer seems to be negative, for we were just lucky. (quoted from Dreyfus 1997: 292)
This example comes from the Indian philosopher Dharmottara, c. 770 CE. The 14th-century Italian philosopher Peter of Mantua presented a similar case:
Let it be assumed that Plato is next to you and you know him to be running, but you mistakenly believe that he is Socrates, so that you firmly believe that Socrates is running. However, let it be so that Socrates is in fact running in Rome; however, you do not know this. (from Peter of MantuasDe scire et dubitare, given in Boh 1985: 95)
Cases like these, in which justified true belief seems in some important sense disconnected from the fact, were made famous in Edmund Gettiers 1963 paper, Is Justified True Belief Knowledge?. Gettier presented two cases in which a true belief is inferred from a justified false belief. He observed that, intuitively, such beliefs cannot be knowledge; it is merely lucky that they are true.
In honour of his contribution to the literature, cases like these have come to be known as Gettier cases. Since they appear to refute the JTB analysis, many epistemologists have undertaken to repair it: how must the analysis of knowledge be modified to accommodate Gettier cases? This is what is commonly referred to as the Gettier problem.
Above, we noted that one role of the justification is to rule out lucky guesses as cases of knowledge. A lesson of the Gettier problem is that it appears that even true beliefs that are justified can nevertheless be epistemically lucky in a way inconsistent with knowledge.
Epistemologists who think that the JTB approach is basically on the right track must choose between two different strategies for solving the Gettier problem. The first is to strengthen the justification condition to rule out Gettier cases as cases of justified belief. This was attempted by Roderick Chisholm;we will refer to this strategy again in7below. The other is to amend the JTB analysis with a suitable fourth condition, a condition that succeeds in preventing justified true belief from being gettiered. Thus amended, the JTB analysis becomes a JTB+Xaccount of knowledge, where the X stands for the needed fourth condition.
Let us consider an instance of this attempt to articulate a degettiering condition.
According to one suggestion, the following fourth condition would do the trick:
In Gettiers cases, the justified true belief is inferred from a justified false belief. So condition(iv)explains why it isnt knowledge. However, this no false lemmas proposal is not successful in general. There are examples of Gettier cases that need involve no inference; therefore, there are possible cases of justified true belief without knowledge, even though condition(iv)is met. Suppose, for example, that James, who is relaxing on a bench in a park, observes an apparent dog in a nearby field. So he believes
Suppose further that the putative dog is actually a robot dog so perfect that it could not be distinguished from an actual dog by vision alone. James does not know that such robot dogs exist; a Japanese toy manufacturer has only recently developed them, and what James sees is a prototype that is used for testing the publics response. Given these assumptions, (d) is of course false. But suppose further that just a few feet away from the robot dog, there is a real dog, concealed from Jamess view. Given this further assumption, Jamess belief in (d) is true. And since this belief is based on ordinary perceptual processes, most epistemologists will agree that it is justified. But as in Gettiers cases, Jamess belief appears to be true only as a matter of luck, in a way inconsistent with knowledge. So once again, what we have before us is a justified true belief that isnt knowledge.Arguably, this belief is directly justified by a visual experience; it is not inferred from any falsehood. If so, then the JTB account, even if supplemented with(iv), gives us the wrong result that James knows (d).
Another case illustrating that clause(iv)wont do the job is the well-known Barn County case (Goldman 1976). Suppose there is a county in the Midwest with the following peculiar feature. The landscape next to the road leading through that county is peppered with barn-facades: structures that from the road look exactly like barns. Observation from any other viewpoint would immediately reveal these structures to be fakes: devices erected for the purpose of fooling unsuspecting motorists into believing in the presence of barns. Suppose Henry is driving along the road that leads through Barn County. Naturally, he will on numerous occasions form false beliefs in the presence of barns. Since Henry has no reason to suspect that he is the victim of organized deception, these beliefs are justified. Now suppose further that, on one of those occasions when he believes there is a barn over there, he happens to be looking at the one and only real barn in the county. This time, his belief is justified and true. But since its truth is the result of luck, it is exceedingly plausible to judge that Henrys belief is not an instance of knowledge. Yet condition(iv)is met in this case. His belief is not the result of any inference from a falsehood. Once again, we see that(iv)does not succeed as a general solution to the Gettier problem.
Another candidate fourth condition on knowledge issensitivity. Sensitivity, to a first approximation, is this counterfactual relation:
Ss belief thatpis sensitive if and only if, ifpwere false,Swould not believe thatp.
A sensitivity condition on knowledge was defended by Robert Nozick (1981). Given a Lewisian (Lewis 1973) semantics for counterfactual conditionals, the sensitivity condition is equivalent to the requirement that, in the nearest possible worlds in which not-p, the subject does not believe thatp.
One motivation for including a sensitivity condition in an analysis of knowledge is that there seems to be an intuitive sense in which knowledge requires not merely being correct, buttrackingthe truth in other possible circumstances. This approach seems to be a plausible diagnosis of what goes wrong in at least some Gettier cases. For example, in Dharmottaras desert water case, your belief that there is water in a certain location appears to be insensitive to the fact of the water. For if there were no water there, you would have held the same belief on the same groundsviz., the mirage.
However, it is doubtful that a sensitivity condition can account for the phenomenon of Gettier cases in general. It does so only in cases in which, had the proposition in question been false, it would have been believed anyway. But, as Saul Kripke (2011: 16768) has pointed out, not all Gettier cases are like this. Consider for instance the Barn County case mentioned above. Henry looks at a particular location where there happens to be a barn and believes there to be a barn there. The sensitivity condition rules out this belief as knowledge only if, were there no barn there, Henry would still have believed there was. But this counterfactual may be false, depending on how the Barn County case is set up. For instance, it is false if the particular location Henry is examining is not one that would have been suitable for the erecting of a barn faade. Relatedly, as Kripke has also indicated (2011: 186), if we suppose that barn facades are always green, but genuine barns are always red, Henrys belief that he sees aredbarn will be sensitive, even though his belief that he sees abarnwill not. (We assume Henry is unaware that colour signifies anything relevant.) Since intuitively, the former belief looks to fall short of knowledge in just the same way as the latter, a sensitivity condition will only handle some of the intuitive problems deriving from Gettier cases.
Most epistemologists today reject sensitivity requirements on knowledge. The chief motivation against a sensitivity condition is that, given plausible assumptions, it leads to unacceptable implications called abominable conjunctions.To see this, suppose first that skepticism about ordinary knowledge is falseordinary subjects know at least many of the things we ordinarily take them to know. For example, George, who can see and use his hands perfectly well, knows that he has hands. This is of course perfectly consistent with a sensitivity condition on knowledge, since if George didnothave handsif theyd been recently chopped off, for instancehe would not believe that he had hands.
Now imagine a skeptical scenario in which George does not have hands. Suppose that George is the victim of a Cartesian demon, deceiving him into believing that he has hands. If George were in such a scenario, of course, he would falsely believe himself not to be in such a scenario. So given the sensitivity condition, George cannot know that he is not in such a scenario.
Although these two verdictsthe knowledge-attributing one about ordinary knowledge, and the knowledge-denying one about the skeptical scenarioare arguably each intuitive, it is intuitively problematic to hold them together. Their conjunction is, in DeRoses term, abominable: George knows that he has hands, but he doesnt know that hes not the handless victim of a Cartesian demon. A sensitivity condition on knowledge, combined with the nonskeptical claim that there is ordinary knowledge, seems to imply such abominable conjunctions.
Most contemporary epistemologists have taken considerations like these to be sufficient reason to reject sensitivity conditions.However, see Ichikawa (2011a) for an interpretation and endorsement of the sensitivity condition according to which it may avoid commitment to abominable conjunctions.
Although few epistemologists today endorse a sensitivity condition on knowledge, the idea that knowledge requires a subject to stand in a particular modal relation to the proposition known remains a popular one. In his 1999 paper, How to Defeat Opposition to Moore, Ernest Sosa proposed that asafetycondition ought to take the role that sensitivity was intended to play. Sosa characterized safety as the counterfactual contrapositive of sensitivity.
Ifpwere false,Swould not believe thatp.
IfSwere to believe thatp,pwould not be false.
Although contraposition is valid for the material conditional \((A \supset B\) iff \(\mathord\sim B \supset \mathord\simA)\), Sosa suggests that it is invalid for counterfactuals, which is why sensitivity and safety are not equivalent. An example of a safe belief that is not sensitive, according to Sosa, is the belief that a distant skeptical scenario does not obtain. If we stipulate that George, discussed above, has never been at risk of being the victim of a Cartesian demonbecause, say, Cartesian demons do not exist in Georges worldthen Georges belief that he is not such a victim is a safe one, even though we saw in the previous section that it could not be sensitive. Notice that although we stipulated that George is not at risk of deceit by Cartesian demons, we didnotstipulate that George himself had any particular access to this fact. Unless he does, safety, like sensitivity, will be anexternalistcondition on knowledge in the access sense. It is also externalist in the state sense, since the truth of the relevant counterfactuals will depend on features outside the subject.
Characterizing safety in these counterfactual terms depends on substantive assumptions about the semantics of counterfactual conditionals.If we were to accept, for instance, David Lewiss or Robert Stalnakers treatment of counterfactuals, including a strong centering condition according to which the actual world is always uniquely closest, all true beliefs would count as safe according to the counterfactual analysis of safety.Sosa intends the relevant counterfactuals to be making a stronger claim, requiring roughly that inall nearbyworlds in whichSbelieves thatp,pis not false.
Rather than resting on a contentious treatment of counterfactuals, then, it may be most perspicuous to understand the safety condition more directly in these modal terms, as Sosa himself often does:
In all nearby worlds whereSbelieves thatp,pis not false.
Whether a JTB+safety analysis of knowledge could be successful is somewhat difficult to evaluate, given the vagueness of the stated nearby condition. The status of potential counterexamples will not always be straightforward to apply. For example, Juan Comesaa (2005) presents a case he takes to refute the requirement that knowled