Attributed to American philosopher Edmund Gettier, Gettier-type counterexamples (called "Gettier-cases") challenge the long-held justified true belief (JTB) account of knowledge.
Some reject Gettier's examples as inadequate justification, while others seek to adjust the JTB account of knowledge and blunt the force of these counterexamples.
In fact, the problem has been known since the Middle Ages, and both Indian philosopher Dharmottara and scholastic logician Peter of Mantua presented examples of it.
[4] Dharmottara, in his commentary c. 770 AD on Dharmakirti's Ascertainment of Knowledge, gives the following two examples:[5][6][7] A fire has just been lit to roast some meat.
The fire hasn’t started sending up any smoke, but the smell of the meat has attracted a cloud of insects.
[5]Various theories of knowledge, including some of the proposals that emerged in Western philosophy after Gettier in 1963, were debated by Indo-Tibetan epistemologists before and after Dharmottara.
[11]: 13–14 Alvin Plantinga rejects the historical analysis: According to the inherited lore of the epistemological tribe, the JTB [justified true belief] account enjoyed the status of epistemological orthodoxy until 1963, when it was shattered by Edmund Gettier... Of course, there is an interesting historical irony here: it isn't easy to find many really explicit statements of a JTB analysis of knowledge prior to Gettier.
Gettier's case is based on two counterexamples to the JTB analysis, both involving a fictional character named Smith.
In both of Gettier's actual examples (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 that "Jones will get the job" (in case I), and that "Jones owns a Ford" (in case II).
The interesting issue that arises is then of how to know which premises are in reality false or true when deriving a conclusion, because as in the Gettier cases, one sees that premises can be very reasonable to believe and be likely true, but unknown to the believer there are confounding factors and extra information that may have been missed while concluding something.
[14] A different perspective on the issue is given by Alvin Goldman in the "fake barns" scenario (crediting Carl Ginet with the example).
But what he does not know is that the neighborhood generally consists of many fake barns—barn facades designed to look exactly like real barns when viewed from the road.
Linda Zagzebski shows that any analysis of knowledge in terms of true belief and some other element of justification that is independent from truth, will be liable to Gettier cases.
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.
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.
Keith Lehrer and Thomas Paxson (1969) proposed another response, by adding a defeasibility condition to the JTB analysis.
[24] The difficulties involved in producing a viable fourth condition have led to claims that attempting to repair the JTB account is a deficient strategy.
[26] 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.
In the first chapter of his book Pyrronian Reflexions on Truth and Justification,[27] Robert Fogelin gives a diagnosis that leads to a dialogical solution to Gettier's problem.
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.
[28] 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.
Mousavirad maintains that the role of justification is to ensure the truth of a proposition, but knowledge itself is the recognition of a fact, regardless of the reliability of its foundation.
Therefore, in Gettier cases, knowledge exists because it is ultimately about becoming aware of facts, irrespective of their origins or the justification supporting them.
In order to do so, within the parameters of the particular counter-example or exemplar, 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 that Gettier has rendered obscure, without thereby lessening the force of JTB to apply in those cases where it actually is crucial.
[30] Chief among these is epistemic minimalists, Crispin Sartwell, who hold that all true belief, including both Gettier's cases and lucky guesses, counts as knowledge.
Some early work in the field of experimental philosophy suggested that traditional intuitions about Gettier cases might vary cross-culturally.
[31] However, subsequent studies have consistently failed to replicate these results, instead finding that participants from different cultures do share the traditional intuition.
[32][33][34] 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.