Over the centuries, these have been some of the more philosophically pondered forms of answer to that question:. If some instances of knowledge accompany a person into life, how will they reveal themselves within his or her life? How would the person, or indeed anyone else, know that he or she has this innate knowledge?
It could depend on what is being known innately — the subject matter of this knowledge with which the person has been born. For example, if people begin life already knowing some grammatical rules an idea famously due to Noam Chomsky: see Stich , ch.
These instances of people learning so readily and predictably would be actions expressing some knowledge- how. But as section 1. Or consider another possible example: knowledge of some mathematics and some logical principles. Seemingly, Plato in the Meno , one of his dialogues accorded people this sort of innate knowledge; as did Leibniz, in his New Essays.
For excerpts from Plato and from Leibniz, see Stich , ch. Plato presented us with a story of a slaveboy, lacking education, whom Socrates brought, via minimal questioning, to a state of remembering some geometrical knowledge. Naturally, it could be difficult to ascertain that any particular knowledge is genuinely innate. Knowledge which is not innate, but which is acquired especially easily, seemingly effortlessly, might nonetheless feel innate.
And as section 1. The answer to that question might be that there is only knowledge-how present — without owing its existence to some related prior knowledge-that.
As ever throughout this article these possibilities are suggested for continued consideration, not as manifestly decisive refutations. Let us consider a few of the vast number of philosophical questions that have arisen about such knowledge. Can there be purely or directly observational knowledge? When you observe a cat sleeping in front of you, do you know observationally — and only observationally — that the cat is sleeping there? Still, is there a perceptual experience present, along with some conceptual or even theoretical knowledge for example, that cats are thus-and-so, that to sleep is to do this-and-not-that, and so forth?
Otherwise, how could your experience constitute your knowing this-content-rather-than-another? Is conceptual knowledge what gives knowledgeable content to your observational experience? Is this so, even for experiences that are as simple as you can imagine having?
Can there be foundational observational knowledge? Wilfrid Sellars engaged famously with this question, confronting what he called the myth of the given. Part of the traditional epistemological appeal of the idea of there being purely or directly observational knowledge was the idea that such knowledge could be foundational knowledge. It would be knowledge given to us in experiences which would be cases of knowledge, yet which would be conceptually simple. Sellars argued, however, that they would not be conceptually so simple.
For example, imagine knowing observationally that here is something white. This would possibly be as simple, in conceptual terms, as observational knowledge could be for you.
Nevertheless, even here the question remains of whether you are applying concepts such as of being here, of being something, and of being white ; and if you are doing so, of whether you must be able to know that you are using them correctly.
Would you need to find even simpler observational experiences, via which you could know what these concepts involve? If so, the other experience — knowing observationally that here is something white — would not have been foundational.
That is, it would not have amounted to a basic piece of knowledge, upon which other pieces of knowledge can be based and which need not itself be based upon other pieces of knowledge.
How much observation is needed for observational knowledge? When you look at what appears to be a cat, for how long must you maintain your gaze if you are to know that you are seeing a cat? Do you need also to walk around it, still looking at it, scrutinising it from different angles, if you are to know that you are seeing a cat?
And what of your other senses? There is a more general question behind those ones: What standard must observational knowledge meet? You are using, it seems, observational evidence; what standard must it meet, if it is to be giving you observational knowledge?
And that sort of question will arise about all evidence and all knowledge. That will become apparent as this article proceeds. Historically, those who believe that some such knowledge is possible are called rationalists about knowledge.
Empiricists , in contrast, believe that all knowledge is observational in its underlying nature, even when it might not seem so. This is the belief that all knowledge is a posteriori — present only after some suitably supportive observations are made. As was done for observational knowledge in section 3. How would there be a priori knowledge? It is difficult, to say the least, for us ever to know that a piece of putative knowledge would not be at all observational, so that it would be gained purely by thought or reflection.
We talk of pure mathematics, for example, and our knowledge of it. Could a priori knowledge be substantive? It might be thought that pure reflection — and hence a priori knowledge — is possible when the truths being known are especially simple, even trivial. So, which is it to be? What standard would a priori knowledge have to satisfy? If there could be a priori knowledge, is it clear what standard it would need to have satisfied? There have long been philosophers for whom part of the appeal in the idea of a priori knowledge is the presumption that it would be infallible.
That is, it would satisfy a conclusive — in effect, a perfect — evidential standard. It would do this because a capacity for pure thought, undistracted by observed contingencies within this world, would be what has provided the a priori knowledge. However, some recent epistemologists for example, BonJour regard that picture as overly optimistic.
The one person is both observing and thinking; and if we expect fallibility to be part of how she observes, maybe we should expect fallibility likewise when she is thinking.
Is it simply obvious that when we are not observing, only thinking, we are more — let alone perfectly — reliable or trustworthy in our views? Or do we also think only imperfectly? And so again we meet the question of the extent to which, in one way or another, we are vulnerable when trying to gain whatever knowledge we can.
Of course, we might claim that we are only vulnerable when focussing just on observation or on reflection — ignoring the other. Surely it will be suggested , much or even all of our knowledge is a mixture — both observational and reasoned. Is that how we will stride forward as knowers? Possibly there are philosophical limits upon the effectiveness of observation by itself and of reason by itself. Still, to combine them is to overcome those limits, or at least enough of them. If each of observation and reflection has limitations of its own, a combination of them might compound those weaknesses.
The result could be a blurring of the two, so that we would never know whether, on a particular occasion, weakness in one — in the observing or in the reflecting — is weakening the whole.
That depends. From the outset of philosophical thinking about knowledge, doubts have never been far away: do we really know what we think we know? And that question was not meant merely to ask whether sometimes we are mistaken in claiming a particular piece of knowledge.
The philosophical concern was more pressing: do we ever know what we think we know? Even when lacking all views on whether we know, could we always fail to know? Is knowledge an attainment forever beyond us — all of us, everyone, all of the time? That question confronts us with a radical sceptical possibility. Possibilities that are less radical but still possibly disturbing, and less widely sceptical but still sceptical, have also been discussed. Is there no knowledge of a physical world?
Is there no scientific knowledge? Is there no knowledge of moral truths? Is there no knowledge of the future? And so it goes. Let us now examine one of these. It is sceptical, partly because it denies something otherwise accepted by almost everyone: sceptical denials are surprising in that sense. Here is how it unfolds. If there is observational knowledge section 3. Those beliefs could be true because there is a physical world with a nature matching what the beliefs attribute to it.
Equally, however, the beliefs could be false because there is no physical world quite, or even at all, as the beliefs claim it to be. And if the beliefs are false, the usual philosophical moral to be drawn would be that they are not knowledge.
Knowledge is only of truths or facts: see section 6. Still, do we ever have reason to regard all of our beliefs about the physical world as actually false?
Perhaps not consciously so, while ever in fact we have the beliefs; for part of having a belief is some sort of acceptance of its content as true, not false. Nevertheless, maybe one can have a belief while accepting that one cannot know quite how one has gained that belief. For instance, even if one feels as though a particular belief has been formed via careful reasoning, perhaps ultimately that belief is present largely because one wants it to be.
And one might concede this, even if reluctantly, as a possibility about oneself. In theory, there are many possible knowledge-precluding ways of gaining a particular belief. Here are a few generically described ways:. But suppose that this experience is actually present as part of your dreaming, not as part of using your senses in a normal way. There seems to you to be a cat; the circumstance feels normal to you; even so, in fact you are asleep, dreaming. Now, could that be how it is on every occasion of your feeling there to be a cat in front of you?
Indeed, we can generalise that question, to this philosophical challenge: Whenever you seem to be having a sensory experience about the world around you, can you know that you are not dreaming at that time? And this question is a challenge, not only a question, because it might not be clear how you could have that knowledge of not dreaming at that time. Any evidence you mention in support of the contention that you are not dreaming will be the same sort of evidence as that which has just been questioned.
I feel awake still. I feel so awake. But your having that feeling could itself be present as part of your dreaming; and if it is, then it is not knowledge.
So, any such experience on your part of reaching for apparently good evidence, of bringing to mind how awake you feel, will merely be more of the same.
That is, it will be just another instance of the same sort of experience as was being questioned in the first place; and it will be no less vulnerable to the possibility of merely being part of a more or less extended moment of dreaming by you.
Your citing these further experiences thus provides no new form of evidence which is somehow above suspicion in this context of questioning the apparently observational evidence the suspicion, remember, of possibly being an experience produced as part of a dreaming experience.
Then the sceptical conclusion follows swiftly. If you never know that your apparent experiences of the physical world around you are not present as part of your dreaming while asleep, you never know that what feels to you like a normally produced belief about the world is not present as part of an experience which precludes that you are thereby having a belief at this time which is knowledge.
Accordingly, for all that you do know about yourself at that time, you fail to have knowledge of your surroundings. In that sense, you might not have knowledge of the physical world around you. Do your apparent beliefs about the world fail in that way to be knowledge? Indeed so, concludes the sceptical reasoning: if for all that you do otherwise know about them they might not be knowledge, then they are not sufficiently well supported by you to actually be knowledge.
On scepticism and dreaming, see Sosa ch. On sceptical reasoning in general, see DeRose and Warfield There are various possible ways of seeking philosophical understanding of a phenomenon. One such approach involves attempting to understand the phenomenon in terms of other phenomena.
If one can do this exhaustively and with full precision, one might even attain a definition of the phenomenon. Sometimes that method is called the search for an analytic reduction of the phenomenon in question. It is also often described as analysing the concept of that phenomenon. But the associated aim should thereby be to understand the phenomenon itself: hopefully, we would understand X by having a full and precise understanding of what it takes for something to satisfy the concept of X.
In , a short paper was published which highlighted — while questioning strikingly — a way of trying to define knowledge. Section 5. Right now, we should have before us a sense of what it questioned — which was a kind of view that has generally been called the justified-true-belief conception of knowledge. So, three distinct phenomena are identified even if only in a generic way , before being combined.
And that combination is being said to be what any — and only any — case of knowledge exemplifies. Knowledge is a belief; but not just any belief. Knowledge is always a true belief; but not just any true belief. A confident although hopelessly uninformed belief as to which horse will win — or even has won — a particular race is not knowledge, even if the belief is true. Knowledge is always a well justified true belief — any well justified true belief. And thus we have the justified-true-belief conception of knowledge.
That is a substantial topic in its own right, but it is not the topic of this article. Still for illustration only , here are two possible forms that justification can take within knowledge:. Often, you have evidence — supportive experiences and views, consciously held — which, overall, favours your belief that such-and-such is the case.
On justification as evidence, see Conee and Feldman Often, you have formed your belief that such-and-such is the case in a way which was likely to have led you to form a true belief.
On reliability as justification, see Goldman Section 6. Almost all epistemologists, at the time and since, have agreed that Gettier disproved the justified-true-belief conception of knowledge. How so? In each of his imagined cases, a person forms a belief which is true and well justified, yet which — this is the usual view, at any rate — is not knowledge.
These situations came to be known as Gettier cases , as did the many subsequent kindred cases. Yes, it is; but only because he himself will get the job and because he himself has ten coins in his pocket — two facts of which he is actually unaware. Many theories have been proposed, as to why such beliefs Gettiered beliefs , as they have come to be called are not knowledge. Collectively, this post-Gettier theorising has generated another independently large epistemological topic — the Gettier problem.
But none of those theories are favored here because epistemology as a whole has not favored one. There has been widespread agreement only on Gettier cases being situations from which knowledge is absent — not on why or how the knowledge is absent.
For recent accounts, see Lycan and Hetherington b. Such doubts, if correct, could allow philosophers to return to a view — a pre-Gettier view — of knowledge as being some sort of justified true belief.
A more varied range of intuitions is needed. Yet that sort of reaction has begun to be questioned by some work that initiated what has since become known as experimental philosophy. Rather than continuing to rely only on what epistemologists and their students would say about such thought-experiments, Jonathan Weinberg, Shaun Nichols, and Stephen Stich asked a wider range of people for their intuitive reactions, including to some Gettier cases.
This wider range included people not affiliated with universities or colleges, along with more people of a non-European ancestry. And the results were at odds with what epistemological orthodoxy would have expected. For example, interestingly more respondents of a Subcontinental ancestry Indian, Pakistani, Bangladeshi than ones of a Western European ancestry replied that the Gettiered beliefs about which they were being asked are instances of knowledge. This does not prove that Gettiered beliefs are knowledge, of course.
But it complicates the epistemological story: to whom — to whose intuitions, if to any — should we be listening here? On intuitions and epistemology, see Weinberg Gettier introduced his challenge section 5. Section 6 will focus upon a range of possible standards that knowledge could be thought to need to meet.
In fact, the belief is true. But how is it made true? It is made true, we saw, not by aspects of Jones, but by aspects of Smith himself — none of which are noticed by his evidence. And so that final belief is not knowledge. Yet here is a counter-challenge described more fully in Hetherington c. Is it possible that to deny Smith this knowledge is to assume, even if not deliberately, an infallibilist standard instead? It will not feel to an epistemologist as if this is happening.
Yet could it be, even so? How would an epistemologist know that an infallibilist standard is not what is being applied, even if only implicitly and even if she is claiming explicitly to be applying a fallibilist standard? Ultimately, epistemologists have relied on appeals to intuition as a way of monitoring their more theoretical interpretations of Gettier cases. And as we found a moment ago there is a question about how decisive that is as a way of knowing exactly what epistemological moral to take from the cases.
So continues this interpretation , if the presence of a fallibilist standard was the only shortcoming in the case, we should not dismiss the belief as failing to be knowledge; for that would be simply an in fallibilist dismissal of the belief. Hence, the question is one of whether that combination — the fallibility and the oddity — should be allowed by fallibilism as being knowledge nonetheless.
Of course knowledge would rarely, even at most, be fallibly present in such an odd way; could it ever be, though? Normally it would not be; abnormally, however, could it be? So, could there be knowledge like this? Might a Gettiered belief be knowledge?
Even if it is rare, is it possible? That question arises because Gettier is challenging only justified-true-belief conceptions of knowledge which include a fallibilist form of justification. Our correlative aim, if we accept the usual reading of Gettier cases, should be to formulate a satisfactory conception of that form of knowledge.
Many philosophical questions about knowledge its nature and availability may be treated as questions about standards. We expect knowledge to amount to something, to be an improvement in some respect upon various forms of non-knowledge. Why is that so? Section 7 will discuss what knowledge is for, hence why it should meet any particular standard.
Section 5 ended by asking about knowledge and infallibilism; we may now consider a wider range of possible standards, beginning with infallibility, which have at times been placed by epistemologists and others upon knowing. There is a recurring temptation, often felt by philosophers and non-philosophers alike, to impose some kind of infallibilist standard upon knowing.
This can even feel intuitive to the person applying the standard. One version of that temptation talks of certainty — not necessarily a subjectively experienced sense of certainty, but what is usually termed an epistemic kind of certainty.
It could also be experienced as certainty. That would not be the important aspect of its being part of the knowing, though. Why would one adopt such a demanding view of knowledge? Perhaps because the alternative could feel too undemanding. Consider the apparent oddity of claims like this:. If it is, perhaps knowing is incompatible with possibly being mistaken; in which case, knowledge does have to involve an epistemic certainty.
The matter is currently being debated for example, Dougherty and Rysiew The spectre of a sceptical conclusion is the most obvious philosophical concern about requiring knowledge to satisfy an infallibilist standard. If knowledge is like that, then how often will anyone succeed in actually having some knowledge? Hazlett, Allan. Moon, Andrew. Nagel, Thomas. Plantinga, Alvin. Warrant: The Current Debate. Warrant and Proper Function. Radford, Colin. Ryle, Gilbert. The Concept of Mind.
Chicago: University of Chicago Press. Shakespeare, William. Edited by Sylvan Barnet. New York: Signet Classics. Sosa, Ernest. Weatherson, Brian. Williamson, Timothy. Knowledge and its Limits. Zagzebski, Linda. Cambridge: Cambridge University Press. The breaking down of a concept into more basic conceptual components, arranged to form a definition. One of two possible values that a given proposition can take with respect to whether or not it is true. In contrast to belief- that , belief- in is not purely cognitive but has an affective component e.
Remaining neutral about whether or not a proposition is true, neither believing nor disbelieving the proposition. Speech that is not strictly true e. A good intellectual trait, such as open-mindedness, intellectual humility, intellectual honesty, curiosity, or understanding. The view that knowledge-level justification the level required for knowledge, which is perhaps more stringent than ordinary justification does not entail truth.
Cases of the sort made famous by epistemologist Edmund Gettier. Such a case occurs when an element of bad epistemic luck is canceled by good epistemic luck, so that it is a justified true belief but not knowledge. Cases in which a justified belief is true on probabilistic grounds often thought to be a counterexample to the JTB analysis.
The view that knowledge is justified true belief plus some fourth condition to rule out Gettier cases and perhaps lottery cases. The philosophical study of the nature, identity, and epistemological significance of intellectual virtues.
The view that knowledge is conceptually basic and hence the starting point for epistemological theorizing , usually in conjunction with the claim that knowledge is of primary epistemic value rather than, say, justification or warrant. Introduction to Philosophy: Epistemology by Brian C.
Barnett is licensed under a Creative Commons Attribution 4. Skip to content Upon completion of this chapter, readers will be able to: Identify the main types of knowledge, the relationships among them, and their distinguishing characteristics. Evaluate analyses of concepts, in particular the traditional analysis of knowledge. Assess the value of conceptual analysis, including its relevance to other topics in epistemology. Explain the role of analysis in shaping the history of the field.
Thomas Nagel by Nagelt via Wikimedia Commons. He uses his now-famous bat example to illustrate: Bats, although more closely related to us than those other species, nevertheless present a range of activity and a sensory apparatus so different from ours that the problem I want to pose is exceptionally vivid though it certainly could be raised with other species.
Table 2 — Justification: The Fine Print It is a simplification to equate the justification condition on knowledge with having good reasons. This table summarizes the standard fine print. The justification condition on knowledge requires: Explanation Examples Belief that is properly based on … It is possible to have a justification but fail to use it. Knowledge requires believing because of good reasons. I know a mathematical proof of the Pythagorean theorem.
My belief would not be properly based. Pragmatic reasons provide pragmatic prudential justification. Knowledge, specifically its epistemic justification component, requires epistemic reasons ones that are truth-directed.
I believe my favorite sports team will win because the thought makes me happy. This reason is not pragmatic, but it is epistemic: it could give me knowledge of who will win.
Knowledge may require sufficiently strong justification though how this degree is determined is up for debate. I have a weak epistemic reason but do not know that it will be blue. Even strong epistemic reasons can be outweighed or undermined by competing reasons defeaters. Only undefeated justification can supply knowledge. I see the flower before me. It appears rose-colored.
I have strong epistemic reason for believing it is rose-colored—until I realize someone has planted rose-colored glasses on my face. What do you think about knowledge attributions in lottery cases? Practice conceptual analysis. Choose a concept that seems relatively easy to break into a short list of components e.
First, produce a simplistic analysis. Second, offer a counterexample to it. Third, revise the analysis to avoid the counterexample. Repeat the process until you are satisfied with the result. Return to Figure 1.
Notice that there are eight distinct bounded regions in the Venn diagram including the space outside all three circles, which represents unjustified false non-beliefs. State one proposition that you can confidently place in each region. In Philosophy , students are often reluctant to formulate their own philosophical views. Consider the following speech excerpt from former US Secretary of State Donald Rumsfeld during a press conference about weapons of mass destruction and the War in Iraq : As we know, there are known knowns; there are things we know we know.
See K. Sangeetha, Chapter 3 of this volume, for more on concepts and their relationship to truth and knowledge. Some subtypes of knowledge -wh are identical to those I already cover e.
The others arguably reduce to the kinds I cover. For example, to know -why is to know -that, where the that -clause expresses a correct answer to the why-question. I have also omitted self-knowledge. It is arguable whether it consists merely in knowing certain truths about oneself, or requires some special self-illuminating experience. In Theaetetus , a later dialogue widely considered his greatest epistemological work, Plato more fully develops the same analysis of knowledge [ca.
I set aside belief -in , which can have non-propositional objects e. It has an affective component e. This is an important distinction in religious epistemology, since many religious believers emphasize the kind of faith that requires belief -in rather than mere belief -that. Even assuming that they do come in degrees, it may be that the kind of belief required for knowledge is restricted to a specific degree of confidence.
Alternatively, perhaps one does know—just not for sure. One may say that we hold unconscious stored beliefs. Another possibility is that we have mere dispositions to believe, which are activated into beliefs when the propositions come to mind. This is a contentious issue. It is also possible to be off the doxastic map altogether, avoiding even suspension—for example, if one has never even considered the proposition in question.
The dialogue ends b—d with no solution. See Daniel Massey in Chapter 4 of this volume for an overview of skepticism. The view that justified beliefs can be false is fallibilism about justification. The view that even knowledge-level justified beliefs can be false is fallibilism about knowledge.
Or do you? Explore Chapter 4 Massey on skepticism to consider this further. There are those who inflate it as described earlier. Long in Chapter 2 of this volume. However, there is at least one way of using these terms that neither inflates nor trivializes. This is the most common usage, which I adopt in this chapter. Gettier and lottery, they say, have led us astray. Yes, intuitions favor them.
But sometimes intuitions are wrong. By utilizing standard explanatory criteria for evaluating theories e. Knowledge- that where the that -clause expresses a proposition. A statement or claim—something which has a truth value i. The belief that the corresponding proposition is false. Propositional justification concerns whether a subject has sufficient reason to believe a given proposition; [ 9 ] doxastic justification concerns whether a given belief is held appropriately.
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 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 This view is sometimes motivated by the thought that, when we consider whether someone knows that p , or wonder which of a group of people know that p , 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.
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. 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 is necessary for knowledge, they do not seem collectively to be sufficient. 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. This example comes from the Indian philosopher Dharmottara, c. The 14 th -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. 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.
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? 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. 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. Given these assumptions, d is of course false. And since this belief is based on ordinary perceptual processes, most epistemologists will agree that it is justified. If so, then the JTB account, even if supplemented with iv , gives us the wrong result that James knows d.
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.
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 is sensitivity. Sensitivity, to a first approximation, is this counterfactual relation:. A sensitivity condition on knowledge was defended by Robert Nozick Given a Lewisian Lewis 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 that p.
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, but tracking the truth in other possible circumstances. This approach seems to be a plausible diagnosis of what goes wrong in at least some Gettier cases. For if there were no water there, you would have held the same belief on the same grounds— viz.
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 —68 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. 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. For example, George, who can see and use his hands perfectly well, knows that he has 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 verdicts—the knowledge-attributing one about ordinary knowledge, and the knowledge-denying one about the skeptical scenario—are arguably each intuitive, it is intuitively problematic to hold them together.
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. 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.
Sosa characterized safety as the counterfactual contrapositive of sensitivity. Sensitivity: If p were false, S would not believe that p. Safety: If S were to believe that p , p would not be false. An example of a safe belief that is not sensitive, according to Sosa, is the belief that a distant skeptical scenario does not obtain. Notice that although we stipulated that George is not at risk of deceit by Cartesian demons, we did not stipulate that George himself had any particular access to this fact.
Characterizing safety in these counterfactual terms depends on substantive assumptions about the semantics of counterfactual conditionals. 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 where S believes that p , p is not false.
The status of potential counterexamples will not always be straightforward to apply. The host does not want Michael to find the party. Suppose Michael never shows up. Had he merely made a slightly different choice about his costume, he would have been deceived. However, it is open to a safety theorist to argue that the relevant skeptical scenario, though possible and in some sense nearby, is not near enough in the relevant respect to falsify the safety condition.
Such a theorist would, if she wanted the safety condition to deliver clear verdicts, face the task of articulating just what the relevant notion of similarity amounts to see also Bogardus Not all further clarifications of a safety condition will be suitable for the use of the latter in an analysis of knowledge. In particular, if the respect of similarity that is relevant for safety is itself explicated in terms of knowledge, then an analysis of knowledge which made reference to safety would be in this respect circular.
This, for instance, is how Timothy Williamson characterizes safety. He writes, in response to a challenge by Alvin Goldman:. In many cases, someone with no idea of what knowledge is would be unable to determine whether safety obtained. Although they could use the principle that safety entails truth to exclude some cases, those are not the interesting ones.
Thus Goldman will be disappointed when he asks what the safety account predicts about various examples in which conflicting considerations pull in different directions.
One may have to decide whether safety obtains by first deciding whether knowledge obtains, rather than vice versa. Williamson Because safety is understood only in terms of knowledge, safety so understood cannot serve in an analysis of knowledge. This is of course consistent with claiming that safety is a necessary condition on knowledge in the straightforward sense that the latter entails the former.
Significant early proponents of this view include Stine , Goldman , and Dretske To be able to know by sight that a particular phone is the 6S model, it is natural to suppose that one must be able to tell the difference between the iPhone 6S and the iPhone 7; the possibility that the phone in question is a newer model is a relevant alternative.
Notice that in these cases and many of the others that motivate the relevant-alternatives approach to knowledge, there is an intuitive sense in which the relevant alternatives tend to be more similar to actuality than irrelevant ones. As such, the relevant alternatives theory and safety-theoretic approaches are very similar, both in verdict and in spirit.
As in the case of a safety theorist, the relevant alternatives theorist faces a challenge in attempting to articulate what determines which possibilities are relevant in a given situation. As we have seen, one motivation for including a justification condition in an analysis of knowledge was to prevent lucky guesses from counting as knowledge. However, the Gettier problem shows that including a justification condition does not rule out all epistemically problematic instances of luck.
Consequently, some epistemologists have suggested that positing a justification condition on knowledge was a false move; perhaps it is some other condition that ought to be included along with truth and belief as components of knowledge. This kind of strategy was advanced by a number of authors from the late s to the early s, although there has been relatively little discussion of it since. One candidate property for such a state is reliability. Part of what is problematic about lucky guesses is precisely that they are so lucky: such guesses are formed in a way such that it is unlikely that they should turn out true.
According to a certain form of knowledge reliabilism, it is unreliability, not lack of justification, which prevents such beliefs from amounting to knowledge. Reliabilist theories of knowledge incorporate this idea into a reliability condition on knowledge. Simple K-Reliabilism replaces the justification clause in the traditional tripartite theory with a reliability clause.
As we have seen, reliabilists about justification think that justification for a belief consists in a genesis in a reliable cognitive process. However, the present proposal is silent on justification. Goldman is the seminal defense of reliabilism about justification; reliabilism is extended to knowledge in Goldman See Goldman for a survey of reliabilism in general.
In the following passage, Fred Dretske articulates how an approach like K-reliabilism might be motivated:. Who needs it, and why? If an animal inherits a perfectly reliable belief-generating mechanism, and it also inherits a disposition, everything being equal, to act on the basis of the beliefs so generated, what additional benefits are conferred by a justification that the beliefs are being produced in some reliable way?
If there are no additional benefits, what good is this justification? Why should we insist that no one can have knowledge without it?
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