Bryan Frances

There is a long history of using facts about disagreement to argue that many of our most precious beliefs are false in a way that can make a difference in our lives. In this essay I go over a series of such arguments, arguing that the best arguments target beliefs that meet two conditions: (i) they have been investigated and debated for a very long time by a great many very smart people who are your epistemic superiors on the matter and have worked very hard under optimal circumstances to figure out if the belief is true, and (ii) as far as you know these people have not come to any significant agreement on the belief and as far as you know those who agree with you are not, as a group, in a better position to judge the belief than those who disagree with you.

If you retain your belief upon learning that a large number and percentage of your recognized epistemic superiors disagree with you, then what happens to the epistemic status of your belief? I investigate that theoretical question as well has the applied case of philosophical disagreement—especially disagreement regarding purely philosophical error theories, theories that do not have much empirical support and that reject large swaths of our most commonsensical beliefs. I argue that even if all those error theories are false, either (a) the average philosopher’s true commonsensical beliefs are epistemically impoverished, or (b) a good portion of philosophy is bunk and philosophers should give up most of their error theories despite the fact that their supporting arguments are generally as good as or even better than other philosophical arguments.

Those of us who take skepticism seriously typically have two relevant beliefs: (a) it’s plausible (even if false) that in order to know that I have hands I have to be able to epistemically neutralize, to some significant degree, some skeptical hypotheses, such as the brain-in-a-vat (BIV) one; and (b) it’s also plausible (even if false) that I can’t so neutralize those hypotheses. There is no reason for us to also think (c) that the BIV hypothesis, for instance, is plausible or probably true. In order to take skepticism seriously it’s sufficient to hold (a) and (b); one need not hold (c). Indeed, philosophers who accept (a) and (b) never endorse (c). Show me a philosopher who suspects that he is a brain in a vat and I’ll show you someone who is deranged! That’s one thing that bothers undergraduates in philosophy. They object: why on earth do some philosophers take the BIV hypothesis to pose any threat at all to our beliefs given that those very same philosophers think that there’s no real chance that the BIV hypothesis is true? Sure, the BIV hypothesis is formally inconsistent with my belief that I have hands, so if the former is true then my belief is false. But so what? Why should that bare inconsistency matter so much? Is this strange attitude amongst philosophers the result of some logic fetish infecting the philosophical community? It is sometimes said that the skeptical hypotheses are not only inconsistent with our beliefs but are explanatory of our experiences, which is supposed to make them more of a threat. But students aren’t fooled: although the skeptical hypotheses may attempt to explain why our experience is as it is, it’s the kind of attempt appropriate for science fiction movies that are all special effects and virtually no plot. No one with any sense of reality will take the evil demon hypothesis to be even tenuously explanatory

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?'

Philosophers often find themselves in disagreement with contemporary philosophers they know full well to be their epistemic superiors on the topics relevant to the disagreement. This looks epistemically irresponsible. I offer a detailed investigation of this problem of the reflective epistemic renegade. I argue that although in some cases the renegade is not epistemically blameworthy, and the renegade situation is significantly less common than most would think, in a troublesome number of cases in which the situation arises the renegade is blameworthy in her disagreement with recognized epistemic superiors. I also offer some thoughts on what it would mean for philosophical practice for us to refrain from being renegades. Finally, I show how a new kind of radical skepticism emerges from modest theses regarding the renegade.