This paper introduces and motivates a solution to a dilemma from peer disagreement. Following Buchak (2021), I argue that peer disagreement puts us in an epistemic dilemma: there is reason to think that our opinions should both change and not change when we encounter disagreement with our epistemic peers. I argue that we can solve this dilemma by changing our credences, but not our beliefs in response to disagreement. I explain how my view solves the dilemma in question, and then (...) offer two additional arguments for it: one related to contents and attitudes, and another related to epistemic peerhood. (shrink)

Metaethical debunking arguments often conclude that no moral belief is epistemically justified. Early versions of such arguments largely relied on metaphors and analogies and left the epistemology of debunking underspecified. Debunkers have since come to take on substantial and broad-ranging epistemological commitments. The plausibility of metaethical debunking has thereby become entangled in thorny epistemological issues. In this thesis, I provide a critical yet sympathetic evaluation of the prospects and challenges facing such arguments in light of this development. In doing so, (...) I address the following central question: how could genealogical information undermine the epistemic justification of moral beliefs? In Part I, I begin answering the central question by extracting explicit and implicit epistemic principles from three popular debunking arguments. These arguments, due to Gilbert Harman, Richard Joyce, and Sharon Street, generate principles concerning ontological parsimony, explanatory dispensability, epistemic insensitivity, lack of epistemic safety, unexplained reliability, epistemic coincidences, and explanatory constraints on rational belief. Having set out the principles tasked with explaining how genealogical information undermines, Part II of the thesis seeks to evaluate whether debunking arguments built on them succeed. To this end, I consider two types of challenges faced by such arguments. First, there are strategies that attempt to block global moral debunking arguments. I argue that one popular such strategy, the so-called ‘third-factor strategy’, has been misunderstood. When understood correctly, it is of no help in answering debunking arguments. I then flesh out an alternative and more promising strategy for blocking such arguments. I then turn to internal challenges facing debunkers, particularly those who rely on ‘explanationist’ principles. I argue that explanationist debunking arguments, as well as most others, fall prey to one or more of four internal challenges: the implausibility of first-order epistemic principles, the threat of overgeneralization, the threat of self-defeat, and the need for costly metaepistemic commitments. I conclude that current debunking arguments fail to establish that no moral belief is justified. By analyzing why existing arguments fail, I develop two conditions of adequacy that debunkers must satisfy in order to navigate the internal challenges successfully. I end by suggesting future directions that debunkers should pursue to rehabilitate the prospects for global moral debunking arguments. (shrink)

This book presents an original discussion and analysis of epistemic peer disagreement. It reviews a wide range of cases from the literature, and extends the definition of epistemic peerhood with respect to the current one, to account for the actual variability found in real-world examples. The book offers a number of arguments supporting the variability in the nature and in the range of disagreements, and outlines the main benefits of disagreement among peers i.e. what the author calls the benefits to (...) inquiry argument. (shrink)

Conciliationism is the view that an agent must revise her belief in a proposition when she becomes aware that there is an epistemic peer who disagrees with her about that proposition. If epistemic peers are anything less than strict cognitive and evidential equals, then even slight differences could explain away why the two parties disagree in the first place. But this strict notion of peerhood never obtains in many, if not most, of real-life cases disagreements between inquirers. One recent account (...) of peerhood which might obtain more frequently in cases of real-life disagreements comes from Elgin Voicing dissent: the ethics and epistemology of making disagreement public, Routledge, New York, pp 10–21, 2018). She argues that two scientists who are epistemic peers can disagree because while they might have the same reasoning abilities, they can have different reasoning styles. While there are merits to Elgin’s account, I argue that two people with different reasoning styles are unlikely to be epistemic peers since such differences could serve to explain away why they disagree. I argue that there is a conception of peerhood which can retain the sceptical force of conciliationism without trivializing or dismissing the problem of disagreement. I then conclude that a particularly attractive argument against conciliationism is gestured at by Elgin in one of her earlier pieces on disagreement. This argument is based on the idea that there are epistemic benefits to be gained from remaining steadfast in the face of disagreement Disagreement, Oxford University Press, Oxford, pp 53–68, 2010). The success of this argument, however, might force an inquirer faced with disagreement to choose between synchronic reasons and diachronic reasons. If Hughes’ recent defense of epistemic dilemmism is correct this may be a feature of the argument, rather than a bug. (shrink)

This article examines the central epistemological issues tied to the recognition of disagreement.

SPECIAL ISSUE ON DISAGREEMENTS: The fact of moral disagreement is often raised as a problem for moral realism. The idea is that disagreement amongst people or communities on moral issues is to be taken as evidence that there are no objective moral facts. While the fact of ‘folk’ moral disagreement has been of interest, the fact of expert moral disagreement, that is, widespread and longstanding disagreement amongst expert moral philosophers, is even more compelling. In this paper, I present three arguments (...) against the anti-realist explanation for widespread and longstanding disagreement amongst expert moral philosophers. Each argument shows the argument from expert disagreement for moral anti-realism, that is, denial of morality’s objectivity, to be in one way or another self-undermining. I conclude that widespread and longstanding disagreement amongst expert moral philosophers is not a problem for moral realism. (shrink)