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The Gettier Problem
By: Impenitent

Edmund Gettier wrote an argument against the idea that justified true belief constitutes knowledge. Gettier’s argument defines knowledge using the form:
(a) S knows that P if and only if (i) P is true, (ii) S believes that P, and (iii) S is justified in believing that P. Gettier then claims that this definition of knowledge is not sufficient. Gettier argues that it is possible for a person to be justified in believing a proposition which is in fact false, thus undercutting the ability of that person to claim to know. Gettier also argues that for any proposition P, if S is justified in believing P and P entails Q and S deduces Q from P and accepts Q as a result of this deduction, then S is justified in believing Q. Gettier presents two cases where the idea that justified true belief constituting knowledge could be questioned as being insufficient. This paper will examine both of Gettier’s cases and demonstrate where both of Gettier’s cases are flawed.

In the first case that Gettier presents, one is introduced to Smith and Jones. Smith and Jones have both applied for the same job. One is told that Smith has strong evidence for the following conjunctive proposition:
(d) Jones is the man who will get the job, and Jones has ten coins in his pocket.
It is further explained that Smith’s evidence for (d) is that the company’s president assured him that Jones would be selected for the position, and that Smith had counted the coins in Jones’ pocket. It is claimed that proposition (d) entails: (e) The man who will get the job has ten coins in his pocket. Gettier argues that Smith sees the entailment from (d) to (e) and accepts (e) on the grounds of (d); furthermore, Gettier argues that Smith is clearly justified in believing that (e) is true.

Gettier then claims that unbeknownst to Smith, that Jones will not get the job but rather Smith actually will be the one hired. Also, while ignorant of the count, Smith has ten coins in his pocket. Gettier claims that proposition (e) is then true, though proposition (d), from which Smith inferred (e) is false. Gettier claims that all of the following are true: (i) (e) is true, (ii) Smith believes that (e) is true, and (iii) Smith is justified in believing that (e) is true. But, Gettier counters, it is just as clear to claim that Smith does not know that (e) is true, because (e) is true for reasons other than those Smith believes.
Gettier introduces other evidence into the story to try to show that the truth of a given proposition is not dependant on specific justification. Gettier has introduced what amounts to the following proposition: (d2) Smith is the man who will get the job, and Smith has ten coins in his pocket. If proposition (d) is true, then proposition (e) may easily and correctly be inferred from proposition (d). If proposition (d2) is true, then proposition (e) may easily and correctly be inferred from proposition (d2). Propositions (d) and (d2) are mutually exclusive so that only one of them may be true at the same time. Gettier argues that Smith may infer proposition (e) from proposition (d) which is false. This is simply not the case. When a true proposition is inferred from another proposition, the other proposition must also be true or the inference is fallacious. Gettier claims that proposition (d) is false. Gettier also claims that proposition (e) is true and proposition (e) is inferred from proposition (d).

In the first example, Gettier claims that all of the following are true: (i) (e) is true, (ii) Smith believes that (e) is true, and (iii) Smith is justified in believing that (e) is true. Gettier claims that it is equally clear that Smith does not know that (e) is true because (e) is correctly inferred from (d2) rather than (d). One could argue that the fallacy committed in the inference of (e) from (d) makes the claim that (iii) Smith is justified in believing (e) is true, actually false because the justification is based upon a fallacy. The claim which Gettier may correctly make is only that some of the following are true: (i) (e) is true, (ii) Smith believes that (e) is true, and (iii) Smith is justified in believing that (e) is true. Condition (iii) must be false because Smith’s justification for the true proposition (e) is made entirely upon the false premise (d). One cannot draw a true conclusion from a false premise. When condition (iii) becomes false, the requirements for knowledge fail.

In the second case, Gettier suggests a different series of propositions.
Smith has strong evidence for the following proposition: (f) Jones owns a Ford. Smith’s evidence for proposition (f) could be that Jones has always previously owned a car and that car was always a Ford; moreover, Jones has just offered to transport Smith while Jones was driving a Ford. Gettier then suggests that a friend of Smith’s named Brown is in a location that Smith does not know. Smith constructs the following three propositions from the proposition (f):
(g) Either Jones owns a Ford, or Brown is in Boston.
(h) Either Jones owns a Ford, or Brown is in Barcelona.
(i) Either Jones owns a Ford, or Brown is in Brest-Litovsk.
Gettier claims that Smith’s construction of (g), (h), and (i) is justified because the first claim in each of the disjuncts is true; and when one of the disjuncts in any disjunctive statement is true, the entire disjunctive statement is considered true by the rules of logic. Gettier argues that Smith is completely justified in believing (g), (h), and (i) on the basis of Smith’s belief in (f) alone, regardless of the fact that Smith is ignorant of the location of Brown.

Gettier then claims firstly that it is the case that Jones does not own a Ford, but rather is driving a rented car; and, secondly, while still unknown to Smith, that Brown happens to actually be in Barcelona. Gettier has introduced what amounts to the following proposition: (f2) Jones does not own a Ford, and Brown is in Barcelona. If it is the case that proposition (f) is true, then it may be claimed that propositions (g), (h) and (i) are all true solely because the first disjunct in each of the propositions is true. If it is the case that proposition (f2) is true, it then follows that propositions (g) and (i) are false because both disjuncts are false, and that proposition (h) is true solely because the second disjunct is true. Propositions (f) and (f2) are mutually exclusive and both cannot be true simultaneously. Gettier then argues that Smith does not know that (h) is true, even though (i) (h) is true, (ii) Smith does believe that (h) is true, and (iii) Smith is justified in believing that (h) is true.

Smith’s creation of propositions (g), (h), and (i) are based on the truth of proposition (f), the first disjunct. Smith’s invention of the location disjunct in each proposition is arbitrary and Smith knows that the location claims made are of his invention and have no bearing on the truth of the three disjunctive propositions. When proposition (f2) is introduced as being true, it follows immediately that Smith’s creation of propositions (g), (h), and (i) are no longer based on the truth of proposition (f). Smith’s justification for the three propositions are entirely dependant upon the truth of proposition (f); and when proposition (f2) is introduced as being true, proposition (f) becomes false. Smith is no longer justified in his creation of the three disjunctive propositions. One cannot claim to be justified in the creation of a disjunctive proposition which will always return a true value, when the first of the disjuncts is indeed false and the truth of the second disjunct is arbitrary. Justification for always returning the true value from such a disjunctive proposition must entail the fact that one of the disjuncts is always indeed true.

In the second example, Gettier claims that all of the following are true: (i) (h) is true, (ii) Smith does believe that (h) is true, and (iii) Smith is justified in believing that (h) is true. Gettier claims that proposition (h) is true on the basis of proposition (f2) of which Smith is completely ignorant. Smith is no longer justified in believing (h) is true, nor is Smith justified in believing (g) or (i) either. When proposition (f2) is made true, proposition (f) is immediately rendered false. Smith has no justification for the creation of the disjunctive propositions (g), (h), and (i) when the truth of the first disjunct is no longer true. The claim which Gettier may correctly make is only that some of the following are true: (i) (h) is true, (ii) Smith does believe that (h) is true, and (iii) Smith is justified in believing that (h) is true. Condition (iii) must be false because Smith is not justified in believing that (h) is true because Smith’s justification for the creation of the disjunctive proposition (h) cannot be based on a false disjunct. Again, when condition (iii) fails, the test for knowledge fails as well.

Gettier concludes by stating that the two examples show that definition (a) does not state a sufficient condition for someone’s knowing a given proposition. In each of the examples presented by Gettier, it is claimed that (i) P is true, (ii) S believes that P, and (iii) S is justified in believing that P. Both of the examples would lead one to believe that S knows P because the three conditions for knowledge are supposedly satisfied in each instance. Within both of the arguments, Gettier maintains that (i) P is true, and (ii) S believes that P and Gettier claims that (iii) S is justified in believing that P is true as well. In each case, Gettier introduces propositions into the arguments that defeat the justification requirement for knowledge because the justification is no longer correctly drawn in either argument. Gettier’s arguments amount to nothing but a falsifying of justification for knowledge. In each case, it has been illustrated how Gettier claims that (iii) S is justified in believing that P is not true.
Gettier claims that (a) S knows that P if and only if (i) P is true,
(ii) S believes that P, and
(iii) S is justified in
believing that P.

In both cases, Gettier claims that all three conditions for knowledge are met but it appears that the given S does not actually know P. Gettier changes the conditions in each case just enough that conditions (i) and (ii) remain true, but condition (iii) must be false in each instance. When condition (iii) is met, knowledge is present; yet in each instance, condition (iii) is not met. There is no justification per condition (iii), so the appearance of knowledge never occurs. Gettier’s claim that justified true belief is not a sufficient condition for someone’s knowing a certain proposition does not follow from his examples simply because in each of the examples, the prerequisite justification for knowledge entailed in (iii) is false in each instance. Proposition (a) remains unscathed by Gettier’s argument.

Article Source: http://journal.ilovephilosophy.com

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