By Alex Ehrlich & AJ Durwin
Abstract: Ever since Plato described knowledge in the Theaetetus and the Meno, three criteria, namely justification, truth, and belief (JTB), have composed the traditional philosophical definition of knowledge. In his 1963 paper “Is Justified True Belief Knowledge?” Edmund Gettier attempts to disestablish the traditional definition of knowledge. He utilizes a thought experiment in which a person appears to meet the knowledge criteria yet still does not seem to have knowledge. In this paper we clarify and specify the definition of knowledge, breaking the justification criterion down into three separate criteria, saving the common sense intuition and the traditional definition of knowledge from The Gettier Problem. All the while this new understanding of knowledge and justification still allows us to consider many everyday knowledge claims to be knowledge (i.e., it is parsimonious but not too restrictive).
In his 1963 paper “Is Justified True Belief Knowledge?” Edmund Gettier claims justified true belief is not sufficient for knowledge because “it is possible for a person to be justified in believing a proposition that is in fact false” 1. Gettier demonstrates how chance events can turn a seemingly justified false belief into a seemingly justified true belief using a thought experiment about Smith, a man applying for a job. Smith has “strong evidence”2 that the other applicant, Jones, will get the job (maybe the boss told Smith) and that Jones has ten coins in his pocket (maybe Smith saw Jones counting them). Accordingly, Smith believes that “(e) the man who will get the job has ten coins in his pocket”3. Yet, Smith gets the job, not Jones, and unbeknownst to Smith, he, too, has ten coins in his pocket. According to Gettier, although Smith thought Jones would get the job, events just so happened to make his belief (e) true and justified. Therefore, Gettier claims one can have justified true belief while “it is equally clear”4 that the belief is not sufficient for knowledge. It is unclear what Gettier meant by “clear”; he seems to be referring tosome kind of intuitive notion of knowledge or the practical everyday layman’s conception. The intuitive or practical notions, while rough, appear to be a useful guide toward a more complete understanding of knowledge.
In order to make sense of the intuitive notion of knowledge Gettier refers to, one needs a new conception of justification. Gettier’s description of justification unintentionally and merely illustrates apparent justification. Only apparent justifications can lead to belief in “a proposition that is in fact false”5. If one has enough information and uses it correctly, one no longer treats apparent justification, which can lead to falsity, as actual justification. For example, if Smith only allowed reliable evidence to justify his beliefs and Smith knew that the boss’ statement about hiring Jones was unreliable, then it would no longer appear to justify Smith’s belief. In Gettier’s conception of the traditional knowledge criteria he does not distinguish between apparent and actual justification.
The traditional requirements for knowledge, according to Gettier, are as follows:
S knows that P IFF
(i) P is true,
(ii) S believes that P, and
(iii) S is justified in believing that P.6
To prevent a misinterpretation, like Gettier’s assumption that justification can lead to false belief, it is beneficial to understand the traditional justification requirement, (iii), as a shortened version of the following:
(iii) S’s believing that Q makes S believe that P,
(iv) If Q is false or if Q has no impact on the truth of P then Q will not make S believe that P and
(v) Were S to have perfect information about everything, (iii) would still be true.
Such an understanding eliminates S’s ability to confuse apparent justification with actual justification. Smith’s knowledge claim in Gettier’s thought experiment violates (v) when P is “the man who will get the job has ten coins in his pocket,” and Q is “the boss said that Jones will get the job and Smith saw Jones count ten coins in his pocket.”7 Smith’s claim violates (v) because if Smith had the whole story the boss’ statement would no longer make him believe P so long as (iv) is true. Smith would realize that it is possible that despite Q, P could be false because the boss’ statement is unreliable. The statement merely appears to be justification if S does not have access to the information that the boss is unreliable. In other words, (v) guarantees that there is no further information that S could attain that would render Q false or show it not to have an impact on the truth of P.
A consequence of (v) is that S would probably have many reasons to believe P. Generally, not all reasons are created equal (i.e., some reasons are better than others). For example, in the court of law, DNA evidence linking someone to a crime is better than eyewitness testimony because DNA evidence is more reliable. However, with perfect information all reasons become equally good. For example, eyewitness testimony is just as reliable as DNA evidence if one can be certain of what the witness observed and that he or she is telling the truth. Criterion (iii) will still be upheld even if, given perfect information, one has what is generally considered to be reasons better than Q. If one has perfect information then reliability issues vanish, making all true and relevant reasons equally trustworthy.
Meeting the five criteria prevent a knowledge claim from falling victim to Gettier-style chance. The criteria distinguish between apparent and actual justification. Skeptical arguments can arise when attempting to ascertain whether a claim meets criteria (i), (iv), and (v). Like in Gettier’s “Is Justified True Belief Knowledge?” the difficulty will remain unaddressed here. This new conception of knowledge and justification is a good first step in figuring out when someone has knowledge. They allow for a continuum of confidence about whether a particular claim is knowledge. The more one learns about the world, the more confident one can be that a particular claim is knowledge. So, as long as one has the correct understanding of justification, yes Gettier, justified true belief is knowledge.
1 qtd. in Huemer 444
2 qtd. in Huemer 445
3 qtd. in Huemer 445
4 qtd. in Huemer 445
5 qtd. in Huemer 444
6 qtd. in Huemer 444
7 qtd. in Huemer 445
Gettier, Edmund. Epistemology : Contemporary Readings. Ed. Michael Huemer. New York: Routledge, 2002.
Alex Ehrlich (’09) is a Accounting and Taxation major at Hofstra University.
AJ Durwin (’10) is a Philosophy major at Hofstra University.
Photo courtesy of jolian.