The Gettier problem is formally a problem in
first-order logic, but the introduction by Gettier of terms such as
believes and
knows moves the discussion into the field of epistemology. Here, the sound (true) arguments ascribed to Smith then need also to be valid (believed) and convincing (justified) if they are to issue in the real-world discussion about
justified true belief. Responses to Gettier problems have fallen into three categories: •
Affirmations of the JTB account: This response affirms the JTB account of knowledge, but rejects Gettier cases. Typically, the proponent of this response rejects Gettier cases because, they say, Gettier cases involve insufficient levels of justification. Knowledge actually requires higher levels of justification than Gettier cases involve. •
Fourth condition responses: This response accepts the problem raised by Gettier cases, and affirms that JTB is
necessary (but not
sufficient) for knowledge. A proper account of knowledge, according to this type of view, will contain at least fourth condition (JTB + ?). With the fourth condition in place, Gettier counterexamples (and other similar counterexamples) will not work, and we will have an adequate set of criteria that are both necessary and sufficient for knowledge. •
Justification replacement response: This response also accepts the problem raised by Gettier cases. However, instead of invoking a fourth condition, it seeks to replace justification itself with some other third condition (?TB) that will make counterexamples obsolete. One response, therefore, is that in none of the above cases was the belief justified because it is impossible to justify anything that is not true. Conversely, the fact that a proposition turns out to be untrue is proof that it was not sufficiently justified in the first place. Under this interpretation, the JTB definition of knowledge survives. This shifts the problem to a definition of justification, rather than knowledge. Another view is that justification and non-justification are not in
binary opposition. Instead, justification is a matter of degree, with an idea being more or less justified. This account of justification is supported by philosophers such as
Paul Boghossian and
Stephen Hicks . In common sense usage, an idea can not only be more justified or less justified but it can also be partially justified (Smith's boss told him X) and partially unjustified (Smith's boss is a liar). Gettier's cases involve propositions that were true and believed, but which had weak justification. In case 1, the premise that the testimony of Smith's boss is "strong evidence" is rejected. The case itself depends on the boss being either wrong or deceitful (Jones did not get the job) and therefore unreliable. In case 2, Smith again has accepted a questionable idea (Jones owns a Ford) with unspecified justification. Without justification, both cases do not undermine the JTB account of knowledge. Other epistemologists accept Gettier's conclusion. Their responses to the Gettier problem, therefore, consist of trying to find alternative analyses of knowledge.
The fourth condition (JTB + G) approaches The most common direction for this sort of response to take is what might be called a "JTB + G" analysis: that is, an analysis based on finding some
fourth condition—a "no-Gettier-problem" condition—which, when added to the conditions of justification, truth, and belief, will yield a set of separately necessary and jointly sufficient conditions.
Goldman's causal theory One such response is that of
Alvin Goldman (1967), who suggested the addition of a
causal condition: a subject's belief is justified, for Goldman, only if the truth of a belief has
caused the subject to have that belief (in the appropriate way); and for a justified true belief to count as knowledge, the subject must
also be able to "correctly reconstruct" (mentally) that causal chain. Goldman's analysis would rule out Gettier cases in that Smith's beliefs are not caused by the truths of those beliefs; it is merely
accidental that Smith's beliefs in the Gettier cases happen to be true, or that the prediction made by Smith: "The winner of the job will have 10 coins", on the basis of his putative belief, (see also
bundling) came true in this one case. This theory is challenged by the difficulty of giving a principled explanation of how an appropriate causal relationship differs from an inappropriate one (without the circular response of saying that the appropriate sort of causal relationship is the knowledge-producing one); or retreating to a position in which justified true belief is weakly defined as the consensus of learned opinion. The latter would be useful, but not as useful or desirable as the unchanging definitions of scientific concepts such as momentum. Thus, adopting a causal response to the Gettier problem usually requires one to adopt (as Goldman gladly does) some form of
reliabilism about
justification.
Lehrer–Paxson's defeasibility condition Keith Lehrer and Thomas Paxson (1969) proposed another response, by adding a
defeasibility condition to the JTB analysis. On their account, knowledge is
undefeated justified true belief—which is to say that a justified true belief counts as knowledge if and only if it is also the case that there is no further truth that, had the subject known it, would have defeated their present justification for the belief. (Thus, for example, Smith's justification for
believing that the person who will get the job has ten coins in his pocket is his justified belief that Jones will get the job, combined with his justified belief that Jones has ten coins in his pocket. But if Smith had known the truth that Jones will
not get the job, that would have defeated the justification for his belief.)
Pragmatism Pragmatism was developed as a philosophical doctrine by
C.S. Peirce and
William James (1842–1910). In Peirce's view, the truth is nominally defined as a sign's correspondence to its object and pragmatically defined as the ideal final opinion to which sufficient investigation
would lead sooner or later. James'
epistemological model of truth was that which
works in the way of belief, and a belief was true if in the long run it
worked for all of us, and guided us expeditiously through our semihospitable world. Peirce argued that
metaphysics could be cleaned up by a pragmatic approach. Consider what effects that might
conceivably have practical bearings you
conceive the objects of your
conception to have. Then, your
conception of those effects is the whole of your
conception of the object. From a pragmatic viewpoint of the kind often ascribed to James, defining on a particular occasion whether a particular belief can rightly be said to be both true and justified is seen as no more than an exercise in
pedantry, but being able to
discern whether that belief led to fruitful outcomes is a fruitful
enterprise. Peirce emphasized
fallibilism, considered the assertion of absolute certainty a barrier to inquiry, and in 1901 defined truth as follows: "Truth is that concordance of an abstract statement with the ideal limit towards which endless investigation would tend to bring scientific belief, which concordance the abstract statement may possess by virtue of the confession of its inaccuracy and one-sidedness, and this confession is an essential ingredient of truth." In other words, any unqualified assertion is likely to be at least a little wrong or, if right, still right for not entirely the right reasons. Therefore, one is more veracious by being Socratic, including recognition of one's own ignorance and knowing one may be proved wrong. This is the case, even though in practical matters one sometimes must act, if one is to act at all, with a decision and complete confidence.
Revisions of JTB approaches The difficulties involved in producing a viable fourth condition have led to claims that attempting to repair the JTB account is a deficient strategy. For example, one might argue that what the Gettier problem shows is not the need for a fourth independent condition in addition to the original three, but rather that the attempt to build up an account of knowledge by conjoining a set of independent conditions was misguided from the outset. Those who have adopted this approach generally argue that epistemological terms like
justification,
evidence,
certainty, etc. should be analyzed in terms of a primitive notion of
knowledge, rather than vice versa. Knowledge is understood as
factive, that is, as embodying a sort of epistemological "tie" between a truth and a belief. The JTB account is then criticized for trying to get and encapsulate the factivity of knowledge "on the cheap", as it were, or via a circular argument, by replacing an irreducible notion of factivity with the conjunction of some of the properties that accompany it (in particular, truth and justification). Of course, the introduction of irreducible primitives into a philosophical theory is always problematic (some would say a sign of desperation), and such anti-reductionist accounts are unlikely to please those who have other reasons to hold fast to the method behind JTB+G accounts.
Fred Dretske's conclusive reasons and Robert Nozick's truth-tracking Fred Dretske developed an account of knowledge which he called "conclusive reasons", revived by
Robert Nozick as what he called the
subjunctive or truth-tracking account. Nozick's formulation posits that proposition p is an instance of knowledge if and only if: •
P is true, and •
S believes that
P is true, and • If
P were true,
S would believe that
P is true, and • If
P weren't true,
S wouldn't believe that
P is true Nozick's definition is intended to preserve Goldman's intuition that Gettier cases should be ruled out by disacknowledging "accidentally" true justified beliefs, but without risking the potentially onerous consequences of building a causal requirement into the analysis. This tactic though, invites the riposte that Nozick's account merely hides the problem and does not solve it, for it leaves open the question of
why Smith would not have had his belief if it had been false. The most promising answer seems to be that it is because Smith's belief was
caused by the truth of what he believes; but that puts us back in the causalist camp. The third condition has come to be known as epistemological
safety, while the fourth has come to be known as epistemological
sensitivity. Criticisms and counter examples (notably the
Grandma case) prompted a revision, which resulted in the alteration of (3) and (4) to limit themselves to the same method (i.e. vision): •
P is true, and •
S believes that
P is true, and • If
P were true,
S (using method M) would believe that
P is true, and • If
P weren't true,
S (using method M) wouldn't believe that
P is true
Saul Kripke has pointed out that this view remains problematic and uses a counterexample called the
Fake Barn Country example, which describes a certain locality containing a number of fake barns or facades of barns. In the midst of these fake barns is one real barn, which is painted red. All the fake barns are not painted red. Jones is driving along the highway, looks up and happens to see the real barn, and so forms the belief: • I see a barn. Though Jones has gotten lucky, he could have just as easily been deceived and not have known it. Therefore, it doesn't fulfill condition 4, for if Jones had seen a fake barn he wouldn't have had any idea it was a fake barn. So, even on the revised account, Jones does not know that he sees a barn. However, Jones could look up and form the belief: • I see a red barn. This meets all four conditions of Nozick’s account, and therefore Jones knows that he sees a red barn. Thus, Nozick is committed to the view that Jones knows that he sees a red barn, but does not know that he sees a barn. This violates the principle of
epistemic closure, which states that one is always in a position to know the consequences of what one knows. Thus, since Jones knows that he sees a red barn, and it is a consequence of him seeing a red barn that he sees a barn, by epistemic closure he should be in a position to know that he sees a barn — but Nozick denies this. Adopting Nozick’s view therefore requires rejecting epistemic closure, which is often seen as an unacceptable cost.
Robert Fogelin's perspectival account In the first chapter of his book
Pyrronian Reflexions on Truth and Justification,
Robert Fogelin gives a diagnosis that leads to a dialogical solution to Gettier's problem. The problem always arises when the given justification has nothing to do with what really makes the proposition true. Now, he notes that in such cases there is always a mismatch between the information available to the person who makes the knowledge-claim of some proposition p and the information available to the evaluator of this knowledge-claim (even if the evaluator is the same person in a later time). A Gettierian counterexample arises when the justification given by the person who makes the knowledge-claim cannot be accepted by the knowledge evaluator because it does not fit with his wider informational setting. For instance, in the case of the fake barn the evaluator knows that a superficial inspection from someone who does not know the peculiar circumstances involved isn't a justification acceptable as making the proposition p (that it is a real barn) true.
Richard Kirkham's skepticism Richard Kirkham has proposed that it is best to start with a definition of knowledge so strong that giving a counterexample to it is logically impossible. Whether it can be weakened without becoming subject to a counterexample should then be checked. He concludes that there will always be a counterexample to any definition of knowledge in which the believer's evidence does not logically necessitate the belief. Since in most cases the believer's evidence does not necessitate a belief, Kirkham embraces skepticism about knowledge; but he notes that a belief can still be rational even if it is not an item of knowledge.
Attempts to dissolve the problem One might respond to Gettier by finding a way to avoid his conclusion(s) in the first place. However, it can hardly be argued that knowledge is justified true belief if there are cases that are justified true belief without being knowledge; thus, those who want to avoid Gettier's conclusions have to find some way to defuse Gettier's counterexamples. In order to do so, within the parameters of the particular counter-example or
exemplar, they must then either accept that • Gettier's cases are not really cases of justified true belief, or • Gettier's cases really are cases of knowledge after all, or demonstrate a case in which it is possible to circumvent surrender to the exemplar by eliminating any necessity for it to be considered that JTB apply in just those areas that Gettier has rendered obscure, without thereby lessening the force of JTB to apply in those cases where it actually is crucial. Then, though Gettier's cases
stipulate that Smith has a certain belief and that his belief is true, it seems that in order to propose (1), one must argue that Gettier, (or, that is, the writer responsible for the particular form of words on this present occasion known as case (1), and who makes assertion's about Smith's "putative" beliefs), goes wrong because he has the wrong notion of
justification. Such an argument often depends on an
externalist account on which "justification" is understood in such a way that whether or not a belief is "justified" depends not just on the internal state of the believer, but also on how that internal state is related to the outside world. Externalist accounts typically are constructed such that Smith's putative beliefs in Case I and Case II are not really justified (even though it seems to Smith that they are), because his beliefs are not lined up with the world in the right way, or that it is possible to show that it is invalid to assert that "Smith" has any significant "particular" belief at all, in terms of JTB or otherwise. Such accounts, of course, face the same burden as causalist responses to Gettier: they have to explain what sort of relationship between the world and the believer counts as a justificatory relationship. Those who accept (2) are by far in the minority in analytic philosophy; generally, those who are willing to accept it are those who have independent reasons to say that more things count as knowledge than the intuitions that led to the JTB account would acknowledge. Chief among these is
epistemic minimalists, such as
Crispin Sartwell, who hold that all true belief, including both Gettier's cases and lucky guesses, counts as knowledge. For his part, Nolbert Briceño, a Venezuelan lawyer, wrote an article entitled "Refutation of the Gettier Problem", where he analyzes Edmund Gettier's reasoning as expressed in his article and claims to demonstrate the errors committed by the latter, thus defending the definition of knowledge given by Plato.
Experimental research Some early work in the field of
experimental philosophy suggested that traditional intuitions about Gettier cases might vary cross-culturally. However, subsequent studies have consistently failed to replicate these results, instead finding that participants from different cultures do share the traditional intuition. More recent studies have been providing evidence for the opposite hypothesis, that people from a variety of different cultures have similar intuitions in these cases. ==See also==