Propositional Knowledge: A Counter-argument to Gettier’s Criticism of the
Tripartite Account of Propositional Knowledge
The Platonic tripartite definition of propositional and fallibilist knowledge found in the last section of the Theaetetus states that knowledge of P occurs when an epistemic agent S knows that P if and only if (1) P is true, (2) S believes that P, and (3) S is justified in believing that P (1992, p.90). A well-known opposition to such an account of propositional knowledge questions the sufficiency of the aforementioned conditions. It is argued that although the aforementioned conditions are necessary in the definition of propositional knowledge such conditions are insufficient due to their failure to ensure S against conditions wherein knowledge of P occurs as a result of mere epistemic luck (Gettier, 1963, p.123). This critique is best known as the Gettier type counter example towards the tripartite definition of propositional knowledge mentioned above.
A logical problem is posited by the Gettier type counter examples. This logical problem is evident in the lack of successful coordination between the truth of P and the reasons that justify S in holding P. Floridi (2004) notes that Gettier type counter examples arise “because the truth and the justification of P happen to be not only independent but also opaquely unrelated that they happen to fail to converge or agree on the same propositional content P…without S realizing it” (p. 64). In order to understand this, it is important to lay down the main assumptions of Gettier’s counter argument that seeks to explicate the aforementioned logical problem.
Gettier’s argument against the tripartite account of propositional knowledge, which involves the conception of knowledge as justified true belief arose as a result of the following claim: knowledge [propositional knowledge] does not merely involve justified true belief. Such a claim is based on the following assumptions.
First, there are instances wherein the warrant is not a sufficient condition for a belief in P. A warrant refers to “the property…that if added to true belief converts into knowledge” (Klein, 2005, p.525). Instances where in the warrant of a claim is not a sufficient condition for a belief in P is evident if one considers that instances of belief and knowledge of P are in some respects epistemically different [other than in terms of truth] from belief of P without knowledge of P.
Second, there are instances wherein warrant is fallible. A warrant is fallible during instances wherein it is likely to be untrue. Instances wherein a warrant is fallible may be due to the insufficiency of truth and justification as warrants for knowledge. It is based on the assumption that there are instances wherein knowledge claims are vulnerable and hence may turn out to be false. The evidence of such, according to Gettier is apparent if one considers that it is possible for P to be false even if S believes that P possesses epistemically significant properties such that whenever a belief possesses such properties and is true the belief may thereby qualify as knowledge.
Lastly, there is the closure of knowledge under obvious and known entailments. The closure of knowledge is dependent on the deductive closure principle which states that “if S knows that P, and S correctly deduces Q from P, then S knows that Q” (Brueckner, 2005, p.164).This last assumption thereby argues that if S is justified in believing P and a deductively valid inference is drawn from P to another belief Q then S is justified in believing Q. This is a result of the entailment of Q from P.
From what was stated above, it is possible to present the usual form of Gettier’s attack against the tripartite account of knowledge. In the initial part of his paper, he claims that the tripartite definition of a knowledge claim “is false in that the conditions stated therein do not constitute a sufficient condition for the truth of the proposition that S knows that P” (Gettier, 1963, p.121). As can be seen in the discussion above, Gettier’s counter argument is based upon a critique of warrant, fallibility, and closure. In other words, Gettier claims that the tripartite definition of knowledge does not provide sufficient conditions for presenting a knowledge claim since there are instances where in S’s conditions for holding P are not in accordance with the conditions for the truth of P. He claims that the tripartite definition of knowledge mentioned above merely presents conditions for S’s holding P but it fails to provide conditions wherein S holds P and P is necessarily true.
It is important to note that combination of the three claims mentioned above leads to a contradiction. From what was mentioned above it follows that it is possible to believe in an obvious deductive consequence of P, which is Q, while in the process retaining the epistemically significant properties of the belief in P. If such is the case, it is possible to have a justified true belief of any property which has led S to have a belief in Q or any other type of belief which has Q’s epistemic characteristics. Note that this contradicts the assumed necessity that P and Q differ from each other since one qualifies as knowledge [S believes and has knowledge of P] whereas Q merely qualifies as a belief [S believes but does not have knowledge of Q]. Gettier’s counter-argument thereby fails due to its view that instances wherein S has a belief of P is similar to instances wherein S has knowledge of P.
Another problem with Gettier’s counter-arguments lies in the cognitively misleading situations which he presents within his arguments as well as the cognitive impairment of the individuals which he presents within his arguments. The problem with this lies in its digression to the usual process of knowledge formation.
Brueckner, A. (2005). Deductive Closure Principle. The Shorter Routledge Encyclopedia of Philosophy. Ed. E. Craig. London: Routledge.
Floridi, L. (2004). On the Logical Unsolvability of the Gettier Problem. Synthese, 142, 61-79.
Gettier, E. (1963). Is Justified True Belief Knowledge? Analysis, 23, 121-23.
Klein, P. (2005). Epistemology. The Shorter Routledge Encyclopedia of Philosophy. Ed. E. Craig. London: Routledge.
Plato. (1992). Theaetetus. Trans. M.J. Levett. Indiana: Hackett Publishing Co.
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