The two faces of evidentialism

In this paper I hope to demonstrate two different (and seemingly independent) ways of interpreting the tenets of evidentialism and show why it is important to distinguish between them. These two ways correspond to those proposed by Feldman (Philosophy and Phenomenological Research, 60, 667–695, 2000, Evidentialism: Essays in epistemology, Oxford University Press, 2004) and Adler (Midwest Studies in Philosophy, 23, 267–285, 1999, Beliefs own ethics, MIT Press, 2002). Feldman’s way of interpreting evidentialism makes evidentialism a principle about epistemic justification, about what we ought to believe. Adler’s, on the other hand, makes evidentialism a principle about how we come to believe, what it is, broadly speaking, rational for us to believe. Having identified this difference, I consider two complaints levied against evidentialism, namely what I call the threshold problem and what I call the availability problem, and hope to show that: (a) only an independent, bracketed justification principle of evidentialism can deal with those problems; (b) the rationality principle of evidentialism is not in fact independent from the justification principle; (c) the rationality principle is hard to motivate; and that (d) in the final analysis the argument for the justification principle depends on the rationality principle. I thus conclude that although it may be convenient for evidentialists to treat these two principles as independent, such an independence cannot be maintained.