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Thalberg sees Gettier as relying upon PDJ to get him from (1) and (2) to (3). But PDJ is inadequate to the task, a fact that Thalberg apparently overlooks. PDJ says only that one is justified in believing the entailments of a proposition that one is justified in believing.²⁵

When we come to the second counterexample, strangely enough Thalberg overlooks the principle of probability, which he is so keen to refer to when considering the move from (1) and (2) to (3). He should have realised that the probability of a disjunctive proposition's being true is always more than the probability of either of its disjunct's being true. According to the theorem of probability theory if p and q are independent propositions then Pr (pvq)=Pr(p)+Pr (q). If Smith is justified in believing a proposition then he is a fortiriori justified in believing a proposition that has a greater probability of being true than the first proposition. Further, "...even if the disjoined proposition possesses no finite probability of being true, Smith is at least as justified in believing the disjunction as he was in believing the original proposition".²⁶

Thalberg also draws a distinction between evidential justifica­tion and what he calls strategic justification.²⁷ If as a matter or" strategy we move from a justified belief to another then the justification may be called strategic justification. The justification which has to do with evidence is called evidential justification. Thalberg contends that in Gettier counterexamples the justifica­tion talked about is strategic justification and Gettier and his followers have mistakenly confused it with evidential justification.

In support of his contention he draws our attention to the fact that Gettier and his followers are reluctant to apply the PDJ principle in their move from propositions (1) and (2) to (3). Indeed, as a matter of strategy it is not prudent to pass from the truth of the conjuncts to the truth of the conjunction. That they are thinking of strategic justification is evident also from their readi­ness to move from the justification of a disjunct to the justification of disjunction with any other disjunct. The disjunction is likely to be true under more than one situation. This makes possible to have justified true belief in the absence of knowledge.

Thalberg next goes on to translate the PDJ principle in terms of the notion of strategic justification: "If S is evidentially or strategically justified to believe p and if p entails q and q is deduced from p then S is strategically justified in believing q".²⁸ In the context of a discussion about the definition of knowledge, how­ever, it is the evidential justification which is relevant and not the strategic justification. Hence the reformulated PDJ principle will not help Gettier.

But as to the distinction between strategic justification and evidential justification it is to be considered whether the notjon of strategic justification is intelligible at all. The word 'strategy' is employed in the context of a discussion about war. Whenever we speak of a strategy we have to speak about a goal to be achieved, for example, winning the war. What then is the goal to be achieved in the epistemic context. One might suggest that here the goal is achieved when we attain true belief. Strategic justification, according to Thalberg, thus docs not involve reference to evidence. But the term 'justification' is employed primarily in moral or ethical context. It is used in a similar but extended sense in epistemology also. Here the phrase 'is justified' means that (the belief) has adequate evidence. In epistemic context then justification is rela­ted to evidence. The notion of strategic justification as distingui­shed from evidential justification is thus a self-defeating notion, • a misnomer. Thalberg thus fails to reject the PDJ principle and the Gettier counterexamples which are based on this principle remain unscathed.

In fact, it seems that Thalberg confuses between the transmissibility of justification through deduction and what Peter Klein calls the partial transitivity of confirmation. According to the partial transitivity of confirmation principle, for any propositions x and y and z if x entails y and z confirms x then z confirms y. Klein argues that Thalberg believed that the truth of transmissibility principle depends upon the truth of the partial transitivity of confirmation principle.²⁹ He thought that since the partial transiti­vity of confirmation principle is false the transmissibility of justification through deduction is also not possible. Though Jones' getting a job and Jones' having ten coins in his pocket confirm the conjunctive proposition "Jones will get the job and Jones has ten coins in his pocket" they do not confirm the proposition "The man who will get the job has ten coins in his pocket". For to confirm the latter proposition it is not enough to say that a particular person called Jones will get the job and that the person has ten coins in his pocket. To confirm it some further evidence is necessary. To quote Kelin:

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