Gettier problem
Encyclopedia
A Gettier problem is a problem in modern epistemology issuing from counter-examples
to the definition of knowledge as justified true belief
(JTB). The problem owes its name to a three-page paper published in 1963, by Edmund Gettier
, called "Is Justified True Belief Knowledge?", in which Gettier argues that this is not necessarily the case. The basic issue is one that everyone is able to relate to: what conditions must be satisfied for a belief to become knowledge? For a proposition to count as knowledge it must (a) be believed, (b) it must be true, and (c) the believer must have good reason for their belief. Indeed, the definition of what counts as a 'reason' is itself complicated, as we feel the reason must be 'relevant', and itself based on 'facts' not merely irrational beliefs. One of the clearer scenarios, known as The Cow in the Field, illustrates the situation when the reasoning held for a belief turns out 'in fact' to be faulty.
Gettier problems tend to show examples where a person is said to satisfy the three conditions of knowledge, but to only have knowledge by accident, thereby demonstrating that the conditions used to define knowledge may be unsatisfactory.
in The Problems of Philosophy
. Russell provides an answer of his own to the problem. Edmund Gettier's formulation of the problem was important as it coincided with the rise of the sort of philosophical naturalism promoted by W.V.O. Quine and others, and was used as a justification for a shift towards externalist
theories of justification. John L. Pollock and Joseph Cruz have stated that the Gettier problem has "fundamentally altered the character of contemporary epistemology" and has become "a central problem of epistemology since it poses a clear barrier to analyzing knowledge".
Alvin Plantinga
rejects the historical analysis:
Despite this, Plantinga does accept that some philosophers before Gettier have advanced a justified true belief account of knowledge, specifically C.I. Lewis and A.J. Ayer.
Farmer Franco goes out to the field and standing by the gate sees in the distance, behind some trees, a white and black shape that he recognizes as his favorite cow. He goes back to the dairy and tells his friend that he knows Daisy is in the field.
Yet, at this point, does Farmer Franco really know it?
The dairyman says he will check too, and goes to the field. There he finds Daisy, having a nap in a hollow, behind a bush, well out of sight of the gate. He also spots a large piece of black and white paper that has got caught in a tree.
Daisy is in the field, as Farmer Franco thought.
But was he right to say that he knew she was?
The philosopher, Martin Cohen
, who described this scenario originally, says that in this case the farmer:
However, we might still feel that the farmer did not really know it; his justified true belief was actually operating independent of the truth. Herein lies the core of the problem of 'knowledge as justified true belief'.
would wish to be able to hold to what is known as the JTB account of knowledge: the claim that knowledge can be conceptually analyzed as justified true belief
— which is to say that the meaning of sentences such as "Smith knows that it rained today" can be given with the following set of necessary and jointly sufficient conditions
:
A subject S knows that a proposition P is true if, and only if
:
) to argue that there are cases of beliefs that are both true and justified—therefore satisfying all three conditions for knowledge on the JTB account—but that do not appear to be genuine cases of knowledge. Gettier, therefore, argued that his counterexamples show that the JTB account of knowledge is false—and thus, that a different conceptual analysis is needed to correctly track what we mean by "knowledge".
Gettier's case is based on two counterexamples
to the JTB analysis. Both of them rely on the established claim (under JTB) that justification is preserved by entailment
, and the further claim that such applies significantly, or can be applied there coherently to the "stipulation" attributed to Smith's putative "belief" in the case of this particular counter-example: that is, that if Smith is justified in believing P, and Smith realizes that the truth of P entails the truth of Q, then Smith would also be justified in believing Q. Gettier calls these counterexamples "Case I" and "Case II":
(see also counterfactual conditional
), the justified true belief came about, if Smith's purported claims are disputable, as the result of entailment (but see also material conditional
) from justified false beliefs, namely, that "Jones will get the job" (in case I), and that "Jones owns a Ford" (in case II). This led some early responses to Gettier to conclude that the definition of knowledge could be easily adjusted, so that knowledge was justified true belief that depends on no false premise
s.
For example:
Again, it seems as though Luke does not "know" that Mark is in the room, even though it is claimed he has a justified true belief that Mark is in the room, but it's not nearly so clear that the perceptual belief that "Mark is in the room" was inferred from any premises at all, let alone any false ones, nor led to significant conclusions on its own; Luke didn't seem to be reasoning about anything; "Mark is in the room" seems to have been part of what he seemed to see.
To save the "no false lemmas" solution, one must logically say that Luke's inference from sensory data does not count as a justified belief unless he consciously or unconsciously considers the possibilities of deception and self-deception. A justified version of Luke's thought process, by that logic, might go like this:
And the third step counts as a false premise. But by the previous argument, this suggests we have fewer justified beliefs than we think we do.
In another example, Matthew drives through an area that appears to have many barns. In fact it contains a great many realistic barn facades, perhaps made to help shoot a Hollywood movie 'on location'. When Matthew looks at the one real barn along his route, he forms the allegedly justified true belief, 'There's a barn over there.' But if he follows the strong requirement for justified belief, then his thought process will follow the previous mentioned steps exactly. A similar process appears in Robert A. Heinlein
's Stranger in a Strange Land
as an example of "Fair Witness" behavior.
http://www.princeton.edu/~jimpryor/courses/epist/notes/gettier.html
Gettier's problem has attracted a range of more sophisticated responses. The different directions that these responses have taken are constrained by the structure of Gettier's argument: if knowledge is solely justified true belief, then there cannot be any cases of justified true belief that are not also cases of knowledge; but Gettier claims that his counterexamples are cases of justified true belief without being cases of knowledge. Therefore, in this account, one is to either accept Gettier's conclusion — and elucidate a new conceptual analysis for knowledge — or else deny one of Gettier's two claims about his counterexamples (that is, either deny that Gettier cases are justified true beliefs, or else accept that Gettier cases are knowledge after all).
One response, therefore, is that in none of the above cases was the belief justified: it is impossible to justify anything which is not true. Under this interpretation the JTB definition of knowledge survives. The problem is now not to define knowledge but to define justification.
However, most contemporary epistemologists accept Gettier's conclusion. Their responses to the Gettier problem, therefore, consist of trying to find alternative analyses of knowledge. They have struggled to discover and agree upon as a beginning any single notion of truth, or belief, or justifying which is wholly and obviously accepted. Truth, belief, and justifying have yet been singly defined. Gettier, for many years a professor at University of Massachusetts Amherst
later also was interested in the epistemic logic
of Hintikka, a Finnish philosopher at Boston University
, who published Knowledge and Belief in 1962.
http://www.umass.edu/chronicle/archives/00/08-25/philosopher41.html
(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. Goldman faces the difficulty, however, 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 nor 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. See Goldmans Theory of justification
.
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 her 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.) However, many critics (such as Marshall Swain [1974]) have argued that the notion of a defeater fact cannot be made precise enough to rule out the Gettier cases without also ruling out a priori cases of knowledge .
was developed as a philosophical doctrine by chiefly C.S.Peirce and William James
(1842–1910). In Peirce's view, 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.
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 pedant
ry, 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; so one is more veracious by being Socratic and including a recognition of one's own ignorance, though in practical matters one sometimes must act, if one is to act at all, with decision and complete confidence of supposed knowledge even though one may end up proven wrong.
, 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 problematical (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.
(1971) developed an account of knowledge which he called "conclusive reasons", revived by Robert Nozick
as what he called the subjunctive or truth-tracking account (1981). Nozick's formulation posits that proposition P is an instance of knowledge when:
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.
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):
That this view though remains problematical has been pointed out in a lecture by Saul Kripke
. The counterexample he uses is called the Fake Barn Country example, which explains that in a certain locality are a number of fake barns or facades of barns. In the midst of these fake barns is one real barn, which is painted red. There is one piece of crucial information for this example: the fake barns cannot be painted red.
Jones is driving along the highway, looks up and happens to see the real barn, and so forms the belief
Though Jones has gotten lucky, he could have just as easily been deceived and not have known it. Therefore it doesn't fulfill premise 4, for if Jones saw a fake barn he wouldn't have any idea it was a fake barn. So this is not knowledge.
An alternate example is if Jones looks up and forms the belief
According to Nozick's view this fulfills all four premises. Therefore this is knowledge, since Jones couldn't have been wrong, since the fake barns cannot be painted red. This is a troubling account however, since it seems the first statement I see a barn can be inferred from I see a red barn, however by Nozick's view the first belief is not knowledge and the second is knowledge.
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. He notes that a belief can still be rational even if it is not an item of knowledge. (see also: fallibilism
)
, they must then either accept that
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 which 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 are epistemic minimalists
such as Crispin Sartwell
, who hold that all true belief, including both Gettier's cases and lucky guesses, counts as knowledge.
has suggested that traditional intuitions about Gettier cases may actually vary cross-culturally. Jonathan Weinberg, Shaun Nichols
and Stephen Stich
conducted cross-cultural empirical studies in which participants were given examples of Gettier cases like the following:
Participants were then asked:
While Western participants' responses were exactly what would have been expected by reading the philosophical literature, (Bob only believes that Jill drives an American car), the majority of East Asian participants actually reported the opposite (Bob truly knows that Jill drives an American car). A subsequent study was conducted with participants from the Indian subcontinent, and even more strongly divergent intuitions about Gettier cases were found. There are many possible explanations for these findings and they may originate in translation ambiguities over the words "justified", "true", "belief" and "knowledge" and possibly depend on the mother-tongue make-up of the survey respondents.
However, subsequent studies were unable to replicate these results for other Gettier cases. One possible explanation of this fact is that East Asian subjects were less familiar with American car models than their Western counterparts.
's play, The Importance of Being Earnest
revolves around a Gettier case. At the start of the play it is revealed that Jack has lied about his name to Gwendolen, telling her he is called Ernest. She claims she would only like a man named Ernest, and would not like a man if his name was not Ernest. However, unknown to both of them, Jack's name really is Ernest. Gwendolen therefore has a justified true belief that her suitor's name is Ernest, but one that is clearly not knowledge, based as it is on a deception.
Counterexample
In logic, and especially in its applications to mathematics and philosophy, a counterexample is an exception to a proposed general rule. For example, consider the proposition "all students are lazy"....
to the definition of knowledge as justified true belief
Justified true belief
Justified true belief is one definition of knowledge that states in order to know that a given proposition is true, one must not only believe the relevant true proposition, but one must also have justification for doing so. In more formal terms, a subject S knows that a proposition P is true if,...
(JTB). The problem owes its name to a three-page paper published in 1963, by Edmund Gettier
Edmund Gettier
Edmund L. Gettier III is an American philosopher and Professor Emeritus at the University of Massachusetts Amherst; he owes his reputation to a single three-page paper published in 1963 called "Is Justified True Belief Knowledge?"Gettier was educated at Cornell University, where his mentors...
, called "Is Justified True Belief Knowledge?", in which Gettier argues that this is not necessarily the case. The basic issue is one that everyone is able to relate to: what conditions must be satisfied for a belief to become knowledge? For a proposition to count as knowledge it must (a) be believed, (b) it must be true, and (c) the believer must have good reason for their belief. Indeed, the definition of what counts as a 'reason' is itself complicated, as we feel the reason must be 'relevant', and itself based on 'facts' not merely irrational beliefs. One of the clearer scenarios, known as The Cow in the Field, illustrates the situation when the reasoning held for a belief turns out 'in fact' to be faulty.
Gettier problems tend to show examples where a person is said to satisfy the three conditions of knowledge, but to only have knowledge by accident, thereby demonstrating that the conditions used to define knowledge may be unsatisfactory.
History
The problem Gettier raised was also raised by Bertrand RussellBertrand Russell
Bertrand Arthur William Russell, 3rd Earl Russell, OM, FRS was a British philosopher, logician, mathematician, historian, and social critic. At various points in his life he considered himself a liberal, a socialist, and a pacifist, but he also admitted that he had never been any of these things...
in The Problems of Philosophy
The Problems of Philosophy
The Problems of Philosophy is one of Bertrand Russell's attempts to create a brief and accessible guide to the problems of philosophy...
. Russell provides an answer of his own to the problem. Edmund Gettier's formulation of the problem was important as it coincided with the rise of the sort of philosophical naturalism promoted by W.V.O. Quine and others, and was used as a justification for a shift towards externalist
Internalism and externalism
Internalism and externalism are two opposing ways of explaining various subjects in several areas of philosophy. These include human motivation, knowledge, justification, meaning and truth. The distinction arises in many areas of debate with similar but distinct meanings...
theories of justification. John L. Pollock and Joseph Cruz have stated that the Gettier problem has "fundamentally altered the character of contemporary epistemology" and has become "a central problem of epistemology since it poses a clear barrier to analyzing knowledge".
Alvin Plantinga
Alvin Plantinga
Alvin Carl Plantinga is an American analytic philosopher and the emeritus John A. O'Brien Professor of Philosophy at the University of Notre Dame. He is known for his work in philosophy of religion, epistemology, metaphysics, and Christian apologetics...
rejects the historical analysis:
Despite this, Plantinga does accept that some philosophers before Gettier have advanced a justified true belief account of knowledge, specifically C.I. Lewis and A.J. Ayer.
The Cow in the Field
Farmer Franco is concerned about his prize cow, Daisy. In fact, he is so concerned that when his dairyman tells him that Daisy is in the field, happily grazing, he says he needs to know for certain. He doesn't want merely to have a 99 percent probability that Daisy is safe, he wants to be able to say that he knows Daisy is safe.Farmer Franco goes out to the field and standing by the gate sees in the distance, behind some trees, a white and black shape that he recognizes as his favorite cow. He goes back to the dairy and tells his friend that he knows Daisy is in the field.
Yet, at this point, does Farmer Franco really know it?
The dairyman says he will check too, and goes to the field. There he finds Daisy, having a nap in a hollow, behind a bush, well out of sight of the gate. He also spots a large piece of black and white paper that has got caught in a tree.
Daisy is in the field, as Farmer Franco thought.
But was he right to say that he knew she was?
The philosopher, Martin Cohen
Martin Cohen (philosopher)
Martin Cohen is a British philosopher, an editor and reviewer who writes on philosophy, philosophy of science and political philosophy....
, who described this scenario originally, says that in this case the farmer:
- believed the cow was safe;
- had evidence that this was so (his belief was justified);
- and it was true that his cow was safe.
However, we might still feel that the farmer did not really know it; his justified true belief was actually operating independent of the truth. Herein lies the core of the problem of 'knowledge as justified true belief'.
Knowledge as justified true belief
Many or most analytic philosophersAnalytic philosophy
Analytic philosophy is a generic term for a style of philosophy that came to dominate English-speaking countries in the 20th century...
would wish to be able to hold to what is known as the JTB account of knowledge: the claim that knowledge can be conceptually analyzed as justified true belief
Justified true belief
Justified true belief is one definition of knowledge that states in order to know that a given proposition is true, one must not only believe the relevant true proposition, but one must also have justification for doing so. In more formal terms, a subject S knows that a proposition P is true if,...
— which is to say that the meaning of sentences such as "Smith knows that it rained today" can be given with the following set of necessary and jointly sufficient conditions
Necessary and sufficient conditions
In logic, the words necessity and sufficiency refer to the implicational relationships between statements. The assertion that one statement is a necessary and sufficient condition of another means that the former statement is true if and only if the latter is true.-Definitions:A necessary condition...
:
A subject S knows that a proposition P is true if, and only if
If and only if
In logic and related fields such as mathematics and philosophy, if and only if is a biconditional logical connective between statements....
:
- P is true
- S believes that P is true, and
- S is justifiedTheory of justificationTheory of justification is a part of epistemology that attempts to understand the justification of propositions and beliefs. Epistemologists are concerned with various epistemic features of belief, which include the ideas of justification, warrant, rationality, and probability...
in believing that P is true
Gettier's counterexamples
Gettier's paper used counterexamples (see also Thought ExperimentThought experiment
A thought experiment or Gedankenexperiment considers some hypothesis, theory, or principle for the purpose of thinking through its consequences...
) to argue that there are cases of beliefs that are both true and justified—therefore satisfying all three conditions for knowledge on the JTB account—but that do not appear to be genuine cases of knowledge. Gettier, therefore, argued that his counterexamples show that the JTB account of knowledge is false—and thus, that a different conceptual analysis is needed to correctly track what we mean by "knowledge".
Gettier's case is based on two counterexamples
Simulacrum
Simulacrum , from the Latin simulacrum which means "likeness, similarity", was first recorded in the English language in the late 16th century, used to describe a representation, such as a statue or a painting, especially of a god...
to the JTB analysis. Both of them rely on the established claim (under JTB) that justification is preserved by entailment
Entailment
In logic, entailment is a relation between a set of sentences and a sentence. Let Γ be a set of one or more sentences; let S1 be the conjunction of the elements of Γ, and let S2 be a sentence: then, Γ entails S2 if and only if S1 and not-S2 are logically inconsistent...
, and the further claim that such applies significantly, or can be applied there coherently to the "stipulation" attributed to Smith's putative "belief" in the case of this particular counter-example: that is, that if Smith is justified in believing P, and Smith realizes that the truth of P entails the truth of Q, then Smith would also be justified in believing Q. Gettier calls these counterexamples "Case I" and "Case II":
Case I
- Smith has applied for a job, but, it is claimed, has a justified belief that "Jones will get the job". He also has a justified belief that "Jones has 10 coins in his pocket". Smith therefore (justifiably) concludes (by the rule of the transitivity of identity) that "the man who will get the job has 10 coins in his pocket".
- In fact, Jones does not get the job. Instead, Smith does. However, as it happens, Smith (unknowingly and by sheer chance) also had 10 coins in his pocket. So his belief that "the man who will get the job has 10 coins in his pocket" was justified and true. But it does not appear to be knowledge.
Case II
- Smith, it is claimed by the hidden interlocutorInterlocutorInterlocutor may refer to:* Interlocutor , the master of ceremonies of a minstrel show* Interlocutor , someone who informally explains the views of a government and also can relay messages back to a government...
, has a justified belief that "Jones owns a Ford". Smith therefore (justifiably) concludes (by the rule of disjunction introductionDisjunction introductionDisjunction introduction or Addition is a valid, simple argument form in logic:or in logical operator notation: A \vdash A \or B The argument form has one premise, A, and an unrelated proposition, B...
) that "Jones owns a Ford, or Brown is in Barcelona", even though Smith has no knowledge whatsoever about the location of Brown.
- In fact, Jones does not own a Ford, but by sheer coincidence, Brown really is in Barcelona. Again, Smith had a belief that was true and justified, but not knowledge.
False premises
In both of Gettier's actual examples,(see also counterfactual conditional
Counterfactual conditional
A counterfactual conditional, subjunctive conditional, or remote conditional, abbreviated , is a conditional statement indicating what would be the case if its antecedent were true...
), the justified true belief came about, if Smith's purported claims are disputable, as the result of entailment (but see also material conditional
Material conditional
The material conditional, also known as material implication, is a binary truth function, such that the compound sentence p→q is logically equivalent to the negative compound: not . A material conditional compound itself is often simply called a conditional...
) from justified false beliefs, namely, that "Jones will get the job" (in case I), and that "Jones owns a Ford" (in case II). This led some early responses to Gettier to conclude that the definition of knowledge could be easily adjusted, so that knowledge was justified true belief that depends on no false premise
False premise
A false premise is an incorrect proposition that forms the basis of a logical syllogism. Since the premise is not correct, the conclusion drawn may be in error...
s.
More general Gettier-style problems
The "no false premises" (or "no false lemmas") solution which was proposed early in the discussion, proved to be somewhat problematic, as more general Gettier-style problems were then constructed or contrived, in which the justified true belief does not seem to be the result of a chain of reasoning from a justified false belief.For example:
- After arranging to meet with Mark for help with homework, Luke arrives at the appointed time and place. Walking into Mark's office Luke clearly sees Mark at his desk; Luke immediately forms the belief 'Mark is in the room. He can help me with my logic homework'. Luke is justified in his belief; he clearly sees Mark at his desk. In fact, it's not Mark that Luke saw; it was a marvelous hologram, perfect in every respect, giving the appearance of Mark diligently grading papers at his desk. Nevertheless, Mark is in the room; he is crouched under his desk reading FregeGottlob FregeFriedrich Ludwig Gottlob Frege was a German mathematician, logician and philosopher. He is considered to be one of the founders of modern logic, and made major contributions to the foundations of mathematics. He is generally considered to be the father of analytic philosophy, for his writings on...
. Luke's belief that Mark is in the room is true (he is in the room, under his desk) and justified (Mark's hologram is giving the appearance of Mark hard at work).
Again, it seems as though Luke does not "know" that Mark is in the room, even though it is claimed he has a justified true belief that Mark is in the room, but it's not nearly so clear that the perceptual belief that "Mark is in the room" was inferred from any premises at all, let alone any false ones, nor led to significant conclusions on its own; Luke didn't seem to be reasoning about anything; "Mark is in the room" seems to have been part of what he seemed to see.
To save the "no false lemmas" solution, one must logically say that Luke's inference from sensory data does not count as a justified belief unless he consciously or unconsciously considers the possibilities of deception and self-deception. A justified version of Luke's thought process, by that logic, might go like this:
- That looks to me like Mark in the room.
- I don't think any factor, right now, could deceive me on this point.
- Therefore, I can safely ignore that possibility.
- "Mark is in the room," (or, 'I can safely treat that as Mark.')
And the third step counts as a false premise. But by the previous argument, this suggests we have fewer justified beliefs than we think we do.
In another example, Matthew drives through an area that appears to have many barns. In fact it contains a great many realistic barn facades, perhaps made to help shoot a Hollywood movie 'on location'. When Matthew looks at the one real barn along his route, he forms the allegedly justified true belief, 'There's a barn over there.' But if he follows the strong requirement for justified belief, then his thought process will follow the previous mentioned steps exactly. A similar process appears in Robert A. Heinlein
Robert A. Heinlein
Robert Anson Heinlein was an American science fiction writer. Often called the "dean of science fiction writers", he was one of the most influential and controversial authors of the genre. He set a standard for science and engineering plausibility and helped to raise the genre's standards of...
's Stranger in a Strange Land
Stranger in a Strange Land
Stranger in a Strange Land is a 1961 science fiction novel by American author Robert A. Heinlein. It tells the story of Valentine Michael Smith, a human who comes to Earth in early adulthood after being born on the planet Mars and raised by Martians. The novel explores his interaction with—and...
as an example of "Fair Witness" behavior.
Other responses to Gettier
The Gettier problem is posed in terms of a problem in first-order logic, but the introduction into the discussion by Gettier of terms such as belief 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 real-world discussion about justified true belief.http://www.princeton.edu/~jimpryor/courses/epist/notes/gettier.html
Gettier's problem has attracted a range of more sophisticated responses. The different directions that these responses have taken are constrained by the structure of Gettier's argument: if knowledge is solely justified true belief, then there cannot be any cases of justified true belief that are not also cases of knowledge; but Gettier claims that his counterexamples are cases of justified true belief without being cases of knowledge. Therefore, in this account, one is to either accept Gettier's conclusion — and elucidate a new conceptual analysis for knowledge — or else deny one of Gettier's two claims about his counterexamples (that is, either deny that Gettier cases are justified true beliefs, or else accept that Gettier cases are knowledge after all).
One response, therefore, is that in none of the above cases was the belief justified: it is impossible to justify anything which is not true. Under this interpretation the JTB definition of knowledge survives. The problem is now not to define knowledge but to define justification.
However, most contemporary epistemologists accept Gettier's conclusion. Their responses to the Gettier problem, therefore, consist of trying to find alternative analyses of knowledge. They have struggled to discover and agree upon as a beginning any single notion of truth, or belief, or justifying which is wholly and obviously accepted. Truth, belief, and justifying have yet been singly defined. Gettier, for many years a professor at University of Massachusetts Amherst
University of Massachusetts Amherst
The University of Massachusetts Amherst is a public research and land-grant university in Amherst, Massachusetts, United States and the flagship of the University of Massachusetts system...
later also was interested in the epistemic logic
Epistemic logic
Epistemic modal logic is a subfield of modal logic that is concerned with reasoning about knowledge. While epistemology has a long philosophical tradition dating back to Ancient Greece, epistemic logic is a much more recent development with applications in many fields, including philosophy,...
of Hintikka, a Finnish philosopher at Boston University
Boston University
Boston University is a private research university located in Boston, Massachusetts. With more than 4,000 faculty members and more than 31,000 students, Boston University is one of the largest private universities in the United States and one of Boston's largest employers...
, who published Knowledge and Belief in 1962.
http://www.umass.edu/chronicle/archives/00/08-25/philosopher41.html
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 necessary and jointly sufficient conditions.Goldman's causal theory
One such response is that of Alvin GoldmanAlvin Goldman
Alvin Ira Goldman is an American professor of Philosophy at Rutgers University in New Jersey. He previously taught at the University of Michigan and at the University of Arizona. He earned his PhD from Princeton University and is married to Holly Smith, a well known ethicist, former...
(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
Bundle theory
Bundle theory, originated by the 18th century Scottish philosopher David Hume, is the ontological theory about objecthood in which an object consists only of a collection of properties, relations or tropes....
) came true in this one case. Goldman faces the difficulty, however, 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 nor 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
Reliabilism
Reliabilism, a category of theories in the philosophical discipline of epistemology, has been advanced both as a theory of knowledge and of justified belief...
about justification. See Goldmans Theory of justification
Theory of justification
Theory of justification is a part of epistemology that attempts to understand the justification of propositions and beliefs. Epistemologists are concerned with various epistemic features of belief, which include the ideas of justification, warrant, rationality, and probability...
.
Lehrer-Paxson's defeasibility condition
Keith LehrerKeith Lehrer
Keith Lehrer is the Regent's Professor emeritus of Philosophy at the University of Arizona with an affiliation with the University of Miami in Florida. He previously taught at the University of Rochester....
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 her present justification for the belief. (Thus, for example, Smith's justification for believing
Epistemic modality
Epistemic modality is a sub-type of linguistic modality that deals with a speaker's evaluation/judgment of, degree of confidence in, or belief of the knowledge upon which a proposition is based. In other words, epistemic modality refers to the way speakers communicate their doubts, certainties, and...
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.) However, many critics (such as Marshall Swain [1974]) have argued that the notion of a defeater fact cannot be made precise enough to rule out the Gettier cases without also ruling out a priori cases of knowledge .
Pragmatism
PragmatismPragmatism
Pragmatism is a philosophical tradition centered on the linking of practice and theory. It describes a process where theory is extracted from practice, and applied back to practice to form what is called intelligent practice...
was developed as a philosophical doctrine by chiefly C.S.Peirce and William James
William James
William James was a pioneering American psychologist and philosopher who was trained as a physician. He wrote influential books on the young science of psychology, educational psychology, psychology of religious experience and mysticism, and on the philosophy of pragmatism...
(1842–1910). In Peirce's view, 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
Metaphysics
Metaphysics is a branch of philosophy concerned with explaining the fundamental nature of being and the world, although the term is not easily defined. Traditionally, metaphysics attempts to answer two basic questions in the broadest possible terms:...
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 pedant
Pedant
A pedant is a person who is excessively concerned with formalism and precision, or who makes a show of his or her learning.-Etymology:The English language word "pedant" comes from the French pédant or its older mid-15th Century Italian source pedante, "teacher, schoolmaster"...
ry, but being able to discern
Decision making
Decision making can be regarded as the mental processes resulting in the selection of a course of action among several alternative scenarios. Every decision making process produces a final choice. The output can be an action or an opinion of choice.- Overview :Human performance in decision terms...
whether that belief led to fruitful outcomes is a fruitful enterprise. Peirce emphasized fallibilism
Fallibilism
Fallibilism is the philosophical principle that human beings could be wrong about their beliefs, expectations, or their understanding of the world...
, 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; so one is more veracious by being Socratic and including a recognition of one's own ignorance, though in practical matters one sometimes must act, if one is to act at all, with decision and complete confidence of supposed knowledge even though one may end up proven wrong.
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 knowledging by conjoining a set of independent conditions was misguided from the outset. Those who have adopted this approach generally argue that epistemological terms like justificationJustification
Justification may refer to:*Theory of justification, a part of epistemology that attempts to understand the justification of propositions and beliefs*Justification , defence in a prosecution for a criminal offense...
, evidence
Evidence
Evidence in its broadest sense includes everything that is used to determine or demonstrate the truth of an assertion. Giving or procuring evidence is the process of using those things that are either presumed to be true, or were themselves proven via evidence, to demonstrate an assertion's truth...
, certainty
Certainty
Certainty can be defined as either:# perfect knowledge that has total security from error, or# the mental state of being without doubtObjectively defined, certainty is total continuity and validity of all foundational inquiry, to the highest degree of precision. Something is certain only if no...
, 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 problematical (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 DretskeFred Dretske
Frederick Irwin Dretske is a philosopher noted for his contributions to epistemology and the philosophy of mind. His more recent work centers on conscious experience and self-knowledge. Additionally, he was awarded the Jean Nicod Prize in 1994...
(1971) developed an account of knowledge which he called "conclusive reasons", revived by Robert Nozick
Robert Nozick
Robert Nozick was an American political philosopher, most prominent in the 1970s and 1980s. He was a professor at Harvard University. He is best known for his book Anarchy, State, and Utopia , a right-libertarian answer to John Rawls's A Theory of Justice...
as what he called the subjunctive or truth-tracking account (1981). Nozick's formulation posits that proposition P is an instance of knowledge when:
- p is true
- S believes that p
- if p were true, S would believe that p
- if p weren't true, S wouldn't believe that p
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.
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
- S believes that p
- if p were true, S (using M) would believe that p
- if p weren't true, S (using method M) wouldn't believe that p
That this view though remains problematical has been pointed out in a lecture by Saul Kripke
Saul Kripke
Saul Aaron Kripke is an American philosopher and logician. He is a professor emeritus at Princeton and teaches as a Distinguished Professor of Philosophy at the CUNY Graduate Center...
. The counterexample he uses is called the Fake Barn Country example, which explains that in a certain locality are a number of fake barns or facades of barns. In the midst of these fake barns is one real barn, which is painted red. There is one piece of crucial information for this example: the fake barns cannot be 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 premise 4, for if Jones saw a fake barn he wouldn't have any idea it was a fake barn. So this is not knowledge.
An alternate example is if Jones looks up and forms the belief
- I see a red barn.
According to Nozick's view this fulfills all four premises. Therefore this is knowledge, since Jones couldn't have been wrong, since the fake barns cannot be painted red. This is a troubling account however, since it seems the first statement I see a barn can be inferred from I see a red barn, however by Nozick's view the first belief is not knowledge and the second is knowledge.
Richard Kirkham's skepticism
Richard KirkhamRichard Kirkham
Richard Ladd Kirkham is an American philosopher. Among his published works are the much-cited Theories of Truth , "Does the Gettier Problem Rest on a Mistake?" Mind , and "On Paradoxes and a Surprise Exam" Philosophia . Kirkham graduated from Cornell College in 1977 and received his Ph.D...
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. He notes that a belief can still be rational even if it is not an item of knowledge. (see also: fallibilism
Fallibilism
Fallibilism is the philosophical principle that human beings could be wrong about their beliefs, expectations, or their understanding of the world...
)
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 exemplarExemplar
Exemplar, in the sense developed by philosopher of science Thomas Kuhn, is a well known usage of a scientific theory.According to Kuhn, scientific practice alternates between periods of normal science and extraordinary/revolutionary science...
, 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 which 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
Externalism
Externalism is a group of positions in the philosophy of mind which hold that the mind is not only the result of what is going on inside the nervous system but also of what either occur or exist outside the subject. It is often contrasted with internalism which holds that the mind emerges out of...
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 are epistemic minimalists
Epistemic minimalism
Epistemic minimalism is the epistemological thesis that mere true belief is sufficient for knowledge. That is, the meaning of "Smith knows that it rained today" is accurately and completely analyzed by these two conditions:...
such as Crispin Sartwell
Crispin Sartwell
Crispin Gallegher Sartwell is an American philosophy professor, self-professed individualist anarchist and journalist. He received his B.A. from the University of Maryland, College Park, his M.A. from Johns Hopkins University and his Ph.D...
, who hold that all true belief, including both Gettier's cases and lucky guesses, counts as knowledge.
Cross-cultural studies
Some recent work in the field of experimental philosophyExperimental philosophy
Experimental philosophy is an emerging field of philosophical inquiry that makes use of empirical data—often gathered through surveys which probe the intuitions of ordinary people—in order to inform research on philosophical questions This use of empirical data is widely seen as opposed to a...
has suggested that traditional intuitions about Gettier cases may actually vary cross-culturally. Jonathan Weinberg, Shaun Nichols
Shaun Nichols
Shaun Nichols is employed as a professor in the Philosophy department at the University of Arizona. He received his PhD. in Philosophy from Rutgers in 1992 and his BA in Philosophy from Stanford. His early work was concerned primarily with questions in theory of mind...
and Stephen Stich
Stephen Stich
Stephen Stich is a professor of Philosophy at Rutgers University. He is also currently an Honorary Professor of the department of Philosophy at the University of Sheffield. Stich's main philosophical interests are in the philosophy of mind, cognitive science, epistemology, and moral psychology. He...
conducted cross-cultural empirical studies in which participants were given examples of Gettier cases like the following:
Bob has a friend, Jill, who has driven a Buick for many years. Bob therefore thinks that Jill drives an American car. He is not aware, however, that her Buick has recently been stolen, and he is also not aware that Jill has replaced
it with a Pontiac, which is a different kind of American car.
Participants were then asked:
Does Bob really know that Jill drives an American car, or does he only believe it?
While Western participants' responses were exactly what would have been expected by reading the philosophical literature, (Bob only believes that Jill drives an American car), the majority of East Asian participants actually reported the opposite (Bob truly knows that Jill drives an American car). A subsequent study was conducted with participants from the Indian subcontinent, and even more strongly divergent intuitions about Gettier cases were found. There are many possible explanations for these findings and they may originate in translation ambiguities over the words "justified", "true", "belief" and "knowledge" and possibly depend on the mother-tongue make-up of the survey respondents.
However, subsequent studies were unable to replicate these results for other Gettier cases. One possible explanation of this fact is that East Asian subjects were less familiar with American car models than their Western counterparts.
In popular culture
Although it predates Gettier's article by over 60 years, the plot of Oscar WildeOscar Wilde
Oscar Fingal O'Flahertie Wills Wilde was an Irish writer and poet. After writing in different forms throughout the 1880s, he became one of London's most popular playwrights in the early 1890s...
's play, The Importance of Being Earnest
The Importance of Being Earnest
The Importance of Being Earnest, A Trivial Comedy for Serious People is a play by Oscar Wilde. First performed on 14 February 1895 at St. James's Theatre in London, it is a farcical comedy in which the protagonists maintain fictitious personae in order to escape burdensome social obligations...
revolves around a Gettier case. At the start of the play it is revealed that Jack has lied about his name to Gwendolen, telling her he is called Ernest. She claims she would only like a man named Ernest, and would not like a man if his name was not Ernest. However, unknown to both of them, Jack's name really is Ernest. Gwendolen therefore has a justified true belief that her suitor's name is Ernest, but one that is clearly not knowledge, based as it is on a deception.
External links
- Text of the article
- Gettier Problems from the Internet Encyclopedia of PhilosophyInternet Encyclopedia of PhilosophyThe Internet Encyclopedia of Philosophy is a free online encyclopedia on philosophical topics and philosophers founded by James Fieser in 1995. The current general editors are James Fieser and Bradley Dowden...