Evidentialism

"As evidentialism is a thesis about epistemic justification, it is a thesis about what it takes for one to believe justifiably, or reasonably, in the sense thought to be necessary for knowledge. Particular versions of evidentialism can diverge in virtue of their providing different claims about what sorts of things count as evidence, what it is for one to have evidence, and what it is for one's evidence to support believing a proposition. Thus, while (EVI) is often referred to as the theory of epistemic justification known as evidentialism, it is more accurately conceived as a kind of epistemic theory. In this light, (EVI) can be seen as the central, guiding thesis of evidentialism. All evidentialist theories conform to (EVI), but various divergent theories of evidentialism can be formulated."

For philosophers Richard Feldman and Earl Conee, evidentialism is the strongest argument for justification because it identifies the primary notion of epistemic justification. They argue that if a person's attitude towards a proposition fits their evidence, then their doxastic attitude for that proposition is epistemically justified. Feldman and Conee offer the following argument for evidentialism as an epistemic justification:

(EJ) Doxastic attitude D toward proposition p is epistemically justified for S at t if and only if having D toward p fits the evidence.

For Feldman and Conee a person's doxastic attitude is justified if it fits their evidence. EJ is meant to show the idea that justification is characteristically epistemic. This idea makes justification dependent on evidence.

Feldman and Conee believe that because objections to EJ have become so prominent their defense for it is appropriate. The theses that object EJ are implying that epistemic justification is dependent upon the "cognitive capacities of an individual or upon the cognitive processes or information-gatherings practices that lead to an attitude." For Feldman and Conee, EJ is in contrast to these theses; EJ contends that the epistemic justification for an attitude is only dependent upon evidence.

Critics of evidentialism sometimes reject the claim that a conclusion is justified only if one's evidence supports that conclusion. A typical counterexample goes like this. Suppose, for example, that Babe Ruth approaches the batter's box believing that he will hit a home run despite his current drunkenness and overall decline in performance in recent games. He realizes that, however unlikely it is that his luck will change, it would increase his chances of hitting a home run if he maintains a confident attitude. In these circumstances, critics of evidentialism argue that his belief that p = Babe Ruth will hit a home run is justified, even though his evidence does not support this belief.

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