Mike Thune

Can known disagreement with our epistemic peers undermine or defeat the justification our beliefs enjoy? Much of the current literature argues for one of two extreme positions on this topic, either that the justification of each person's belief is (fully) defeated by the awareness of disagreement, or that no belief is defeated by this awareness. I steer a middle course and defend a principle describing when a disagreement yields a partial defeater, which results in a loss of some, but not all, of the justification of a belief. I show that the 'no defeater' view is too strong. I also offer reasons for thinking that the 'full defeater' view is similarly mistaken.

Consider two people who disagree about some important claim (e.g. the future moral and political consequences of current U.S. economic policy are X). They each believe the other person is in possession of relevant evidence, is roughly equally competent to evaluate that evidence, etc. From the epistemic point of view, how should such recognized disagreement affect their doxastic attitude toward the original claim? Recent research on the epistemology of disagreement has converged upon three general ways of answering this question. The focus of this article is twofold: first, we summarize and give a brief evaluation of the main accounts of the epistemic significance of disagreement; then, we look at what these accounts suggest about how to epistemically assess both inter-religious and intra-religious disagreements. A final section offers recommendations for further research.

Alvin Plantinga and other philosophers have argued that exclusive religious belief can be rationally held in response to certain experiences – independently of inference to other beliefs, evidence, arguments, and the like – and thus can be 'properly basic'. We think that this is possible only until the believer acquires the defeater we develop in this paper, a defeater which arises from an awareness of certain salient features of religious pluralism. We argue that, as a consequence of this defeater, continued epistemic support for exclusive religious belief will require the satisfaction of non-basic epistemic criteria (such as evidence and/or argumentation). But then such belief will no longer be properly basic. If successful, we will have presented a challenge not only to Plantinga's position, but also to the general view (often referred to as 'reformed epistemology') according to which exclusive religious belief can be properly basic

In my “Plantinga Untouched,” I argued that James Beilby’s recent objection to Plantinga’s EAAN was unsuccessful. Beilby has sincereplied that a naturalist can grant the Inscrutability Thesis and yet be alethically rational in hoping for a high P(R/N and future developments of E) and, therefore, needn’t accept the alethic defeater for R. I argue that this is impossible, since a naturalist cannot consistently grant that thesis and meet Beilby’s own criteria for alethic hope. Consequently, Plantinga is (still) right in maintaining that the naturalist who grants that P(R/N&E) is low or inscrutable has a defeater for R.

In my "Plantinga Untouched: A Response to Beilby on the Evolutionary Argument against Naturalism" (Philosophia Christi 7:1 [2005], pp. 157-67), I argue that James Beilby's (2003) objection to Alvin Plantinga's "Evolutionary Argument against Naturalism" (EAAN) is unsuccessful. Along the way, I argue that the move to grant Plantinga's 'inscrutability thesis' - namely, that the probability that our cognitive faculties are reliable, given naturalism and evolutionary theory [P(R/N&E)], is low or inscrutable - presents significant problems for the one who accepts N&E.