Online research in philosophy

What is the nature of rational disagreement? A number of philosophers have recently addressed this question by examining how we should respond to epistemic conflict with a so-called epistemic peer—that is, someone over whom you enjoy no epistemic advantage. Some say that you're rationally required to suspend judgment in these cases—thereby denying the very possibility of a certain kind of rational disagreement. Others say that it's permissible to retain your beliefs even in the face of epistemic conflict. By distinguishing between close peers and distant peers, I argue that it's rational to respond to different types of peers in different ways. I also argue that remote peers—a particularly distant kind of distant peer—provide us with an important lesson in epistemic humility.

Abstract Suppose you know that someone is your epistemic peer regarding some topic. You admit that you cannot think of any relevant epistemic advantage you have over her when it comes to that topic; you admit that she is just as likely as you to get P?s truth-value right. Alternatively, you might know that she is your epistemic superior regarding the topic. And then after learning this about her you find out that she disagrees with you about P. In those situations it appears that the confidence with which one holds one?s belief should be significantly reduced. My primary goal in this essay is to present and reflect upon a set of cases of disagreement that have not been discussed in the literature but are vital to consider. I argue that in the new cases one is reasonable in not lowering one?s confidence in the belief. Then I articulate and defend an ambitious principle, the Disagreement Principle, meant to answer the question ?Under what conditions am I epistemically blameworthy in retaining my belief with the same level of confidence after I have discovered recognized peers or superiors who disagree with me??

This paper assesses the comparative reliability of two beliefrevision rules relevant to the epistemology of disagreement, the Equal Weight and Stay the Course rules. I use two measures of reliability for probabilistic belief-revision rules, Calibration and Brier Scoring, to give a precise account of epistemic peerhood and epistemic reliability. On the Calibration measure of reliability, epistemic peerhood is easy to come by, and employing the Equal Weight rule in the case of peer disagreement generally renders you less reliable than Staying the Course. On the Brier-Score measure of reliability, epistemic peerhood is much more difficult to come by, but employing the Equal Weight rule in the case of peer disagreement always renders you more reliable than Staying the Course. I conclude with some lessons we can draw from these formal results for the normative issue of rational belief-change in the face of peer disagreement, foreshadowing part II of my work on this topic, “On the Rationality of Belief-Invariance in Light of Peer Disagreement.”.

This paper considers two questions. First, what is the scope of the Equal Weight View? Is it the case that meeting halfway is the uniquely rational method of belief-revision in all cases of known peer disagreement? The answer is no. It is sometimes rational to maintain your own opinion in the face of peer disagreement. But this leaves open the possibility that the Equal Weight View is indeed sometimes the uniquely rational method of belief revision. Precisely what is the skeptical import of this fact; is it the case that some form of skepticism triumphs in such cases? The answer to this question is also no. As it turns out, the situations in which it is most plausible that the Equal Weight view is a rational requirement are the ones in which meeting halfway with a disagreeing peer brings you closer to, and not farther from, knowledge. I argue for these theses in a novel way; by looking at the comparative reliability of belief-invariance and meeting halfway using measures of reliability for degrees of belief, and by drawing normative conclusions from such results. The conclusions here can have the effect of reframing the entire debate in the epistemology of disagreement.

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.

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.

The proportional weight view in epistemology of disagreement generalizes the equal weight view and proposes that we assign to judgments of different people weights that are proportional to their epistemic qualifications. It is shown that if the resulting degrees of confidence are to constitute a probability function, they must be the weighted arithmetic means of individual degrees of confidence, while if the resulting degrees of confidence are to obey the Bayesian rule of conditionalization, they must be the weighted geometric means of individual degrees of confidence. The double bind entails that the proportional weight view (and its moderate adjustment in favor of one’s own judgment) is inconsistent with Bayesianism.

An intuitive view regarding the epistemic significance of disagreement says that when epistemic peers disagree, they should suspend judgment. This abstemious view seems to embody a kind of detachment appropriate for rational beings; moreover, it seems to promote a kind of conciliatory inclination that makes for irenic and cooperative further discussion. Like many strategies for cooperation, however, the abstemious view creates opportunities for free-riding. In this essay, the authors argue that the believer who suspends judgment in the face of peer disagreement is vulnerable to a kind of manipulation on the part of more tenacious peers. The result is that the abstemious view can have the effect of encouraging dogmatism.

How should we respond to cases of disagreement where two epistemic agents have the same evidence but come to different conclusions? Adam Elga has provided a Bayesian framework for addressing this question. In this paper, I shall highlight two unfortunate consequences of this framework, which Elga does not anticipate. Both problems derive from a failure of commutativity between application of the equal weight view and updating in the light of other evidence.

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.