How should you update your (degrees of) belief about a proposition when you find out that someone else — as reliable as you are in these matters — disagrees with you about its truth value? There are now several different answers to this question — the question of `peer disagreement' — in the literature, but none, I think, is plausible. Even more importantly, none of the answers in the literature places the peer-disagreement debate in its natural place among the most (...) general traditional concerns of normative epistemology. In this paper I try to do better. I start by emphasizing how we cannot and should not treat ourselves as `truthometers' — merely devices with a certain probability of tracking the truth. I argue that the truthometer view is the main motivation for the Equal Weight View in the context of peer disagreement. With this fact in mind, the discussion of peer disagreement becomes more complicated, sensitive to the justification of the relevant background degrees of belief (including the conditional ones), and to some of the most general points that arise in the context of discussions of scepticism. I argue that thus understood, peer disagreement is less special as an epistemic phenomenon than may be thought, and so that there is very little by way of positive theory that we can give about peer disagreement in general. (shrink)

This book is a defense of modal realism; the thesis that our world is but one of a plurality of worlds, and that the individuals that inhabit our world are only a few out of all the inhabitants of all the worlds. Lewis argues that the philosophical utility of modal realism is a good reason for believing that it is true.

Is belief in God epistemically justified? That's the question at the heart of this volume in the Great Debates in Philosophy series, with Alvin Plantinga and Michael Tooley each addressing this fundamental question with distinctive arguments from opposing perspectives. The first half of the book contains each philosopher's explanation of his particular view; the second half allows them to directly respond to each other's arguments, in a lively and engaging conversation Offers the reader a one of a kind, interactive discussion (...) Forms part of the acclaimed Great Debates in Philosophy series. (shrink)

I argue that Cartesian skepticism about the external world leads to a vicious regress of skeptical attitudes, the only principled and unproblematic response to which requires refraining from taking the very first skeptical step.

Some philosophers believe that when epistemic peers disagree, each has an obligation to accord the other's assessment the same weight as her own. I first make the antecedent of this Equal-Weight View more precise, and then I motivate the View by describing cases in which it gives the intuitively correct verdict. Next I introduce some apparent counterexamples – cases of apparent peer disagreement in which, intuitively, one should not give equal weight to the other party's assessment. To defuse these apparent (...) counterexamples, an advocate of the View might try to explain how they are not genuine cases of peer disagreement. I examine David Christensen's and Adam Elga's explanations and find them wanting. I then offer a novel explanation, which turns on a distinction between knowledge from reports and knowledge from direct acquaintance. Finally, I extend my explanation to provide a handy and satisfying response to the charge of self-defeat. (shrink)

How much should your confidence in your beliefs be shaken when you learn that others – perhaps 'epistemic peers' who seem as well-qualified as you are – hold beliefs contrary to yours? This article describes motivations that push different philosophers towards opposite answers to this question. It identifies a key theoretical principle that divides current writers on the epistemology of disagreement. It then examines arguments bearing on that principle, and on the wider issue. It ends by describing some outstanding questions (...) that thinking about this issue raises. (shrink)

In this impressive second edition of Theory of Knowledge, Keith Lehrer introduces students to the major traditional and contemporary accounts of knowing. Beginning with the traditional definition of knowledge as justified true belief, Lehrer explores the truth, belief, and justification conditions on the way to a thorough examination of foundation theories of knowledge,the work of Platinga, externalism and naturalized epistemologies, internalism and modern coherence theories, contextualism, and recent reliabilist and causal theories. Lehrer gives all views careful examination and concludes that (...) external factors must be matched by appropriate internal factors to yield knowledge. This match of internal and external factors follows from Lehrer’s new coherence theory of undefeated justification. In addition to doing justice to the living epistemological traditions, the text smoothly integrates several new lines that will interest scholars. Also, a feature of special interest is Lehrer’s concept of a justification game.This second edition of Theory of Knowledge is a thoroughly revised and updated version that contains several completely new chapters. Written by a well-known scholar and contributor to modern epistemology, this text is distinguished by clarity of structure, accessible writing, and an elegant mix of traditional material, contemporary ideas, and well-motivated innovation. (shrink)

Looking back on it, it seems almost incredible that so many equally educated, equally sincere compatriots and contemporaries, all drawing from the same limited stock of evidence, should have reached so many totally different conclusions---and always with complete certainty.

How should one react when one has a belief, but knows that other people—who have roughly the same evidence as one has, and seem roughly as likely to react to it correctly—disagree? This paper argues that the disagreement of other competent inquirers often requires one to be much less confident in one’s opinions than one would otherwise be.

How should one react when one has a belief, but knows that other people—who have roughly the same evidence as one has, and seem roughly as likely to react to it correctly—disagree? This paper argues that the disagreement of other competent inquirers often requires one to be much less confident in one’s opinions than one would otherwise be.

Contemporary epistemology of peer disagreement has largely focused on our immediate normative response to prima facie instances of disagreement. Whereas some philosophers demand that we should withhold judgment (or moderate our credences) in such cases, others argue that, unless new evidence becomes available, disagreement at best gives us reason to demote our interlocutor from his peer status. But what makes someone an epistemic peer in the first place? This question has not received the attention it deserves. I begin by surveying (...) different notions of ‘epistemic peer’ that have been peddled in the contemporary literature, arguing that they tend to build normative assumptions about the correct response to disagreement into the notion of peerhood. Instead, I argue, epistemic peerhood needs to be taken seriously in its own right. Importantly, for epistemic agents to count as peers, they should exhibit a comparable degree of reflective awareness of the character and limitations of their own knowledge. (shrink)

This chapter contains sections titled: Theism Alternatives to Theism Naturalism and Its Woes Conclusion.

Looking back on it, it seems almost incredible that so many equally educated, equally sincere compatriots and contemporaries, all drawing from the same limited stock of evidence, should have reached so many totally different conclusions---and always with complete certainty.

An explanatory coherence theory of justification is sketched and then defended against a number of recent objections: conservatism and relativism; wild and crazy beliefs; reliability; warranted necessary falsehoods; basing; distant, unknown coherences; Sosa's “self- and present-abstracts”; and Bayesian impossibility results.