Social Epistemology Review and Reply Collective, 2014 Vol. 3, No. 4, 1-3. http://wp.me/P1Bfg0-Y9 A Puzzle About Disagreement and Rationality Jonathan Matheson, University of North Florida In the literature on the epistemology of peer disagreement, Conciliationists claim that discovering that an epistemic peer disagrees with you about a proposition provides you with a defeater for your justification for holding the doxastic attitude you have toward that proposition (see Christensen 2007, Elga 2007, and Feldman 2006). After all, you have gained a powerful reason to believe that you have made a mistake (either by misevaluating the shared evidence or by having acquired misleading evidence). Applied more generally, Conciliationism claims that we should be agnostic about claims that are significantly controversial amongst the relevant experts (see Carey and Matheson 2013). After all, significant disagreement amongst the experts indicates that either our evidence on the topic is not very good or that we aren't very good at evaluating it. In either case, agnosticism toward the disputed proposition seems called for. So, according to Conciliationism, rationality calls for a removal of dissenting opinions – in the end, the disagreement should lead to skepticism toward the disputed proposition for all the involved parties. However, psychological data regarding group inquiry indicates that groups with dissenting members are more successful in their inquiry with respect to the disputed propositions. Such groups do better at avoiding confirmation bias and belief bias (see Mercier 2012, Nickerson 1998, and Dawson et al. 2002) plausibly by better offering a system of checks and balances in their inquiry. In brief, the research points to the conclusion those groups with dissenting members do better at arriving at accurate beliefs on those disputed topics at the culmination of inquiry. So, according to the psychological data, rationality calls for preserving dissent – disagreement should be embraced as a great tool for getting at true beliefs. Upon first glance, it looks as though the psychological data is in direct conflict with a plausible epistemological account of the epistemic significance of disagreement. We want to have true beliefs and to avoid false beliefs, but Conciliationism tells us to do this by being agnostic in the face of disagreement (such that the disagreement disappears) while the psychological data tells us to embrace the disagreement (if not to even artificially foster it!). While Conciliationism and the psychological data do pull us in different directions, I don't believe that this indicates that they are in conflict. The term 'rational' (and its cognates) is far from univocal. In this case, we can see that the Conciliationist and the psychologists are after different senses of 'rational'. While both may be seen as offering answers to the question, "What should I believe?" the Conciliationist is addressing a version of this question that is solely concerned with the proper response to the subject's evidence at the time in question. In contrast, the psychologists have a version of this question that is focused on means/ends rationality and what will do us best in the long run. In this way, we may think of the Conciliationists as addressing a synchronic version 1 Social Epistemology Review and Reply Collective, 2014 Vol. 3, No. 4, 1-3. http://wp.me/P1Bfg0-Y9 of our question "What should I believe?" while the psychological research is more concerned with a diachronic version of the question. Consider the following case given by Earl Conee: SUE THE SCIENTIST1: Suppose that there is a scientist, Sue, who is knowingly afflicted with an illness that is virtually always fatal. However, suppose that Sue also knows that the belief that she will recover would slightly improve her chances. If she manages to adopt this belief and it does help to affect her recovery and thereby contributes to a subsequent acquisition of knowledge, then the belief has the instrumental epistemic merit of making this contribution to knowledge. The prospect of this further knowledge can make it rational for her to adopt the belief in spite of its conflict with what her evidence indicates about the likelihood of her recovery. (1987, 316) While Sue's belief may have all kinds of prudential merit, what Conee points out is that her belief can have epistemic merit as well. While Sue's belief that she will recover is not supported by her evidence at the time, having that particular belief nevertheless best promotes her ability to gain other true and rational beliefs. So, to the question, "What should Sue believe?" we can see that there are divergent answers to the synchronic and diachronic versions of this question. The answer to the synchronic version is that she should believe that she will likely not recover. The answer to the diachronic version is that she should believe that she will make a recovery. However, since these answers are to distinct versions of the more general question, they are in no way in conflict. There is no pressure from the answer to the diachronic question to change our answer to the synchronic question (and vice versa). All of this leaves open which version of this question we ought to be more concerned with. Since the different versions of the question offer different prescriptions with respect to what we ought to believe, the issue of which version we ought to be more concerned with is both relevant and pressing. I am not offering a solution to that problem here, but only noting that while there is this further issue, the psychological data regarding the rationality of dissenting groups should not be seen as a threat to Conciliationism about the epistemic significance of disagreement. While Conciliationism and the psychological research give different answers to the question "What should I believe?" I am contending that they are answers to distinct versions of this general question. While both may be seen as answering the general question, "What should I believe?" the Conciliationsists are interested in a synchronic version of that question while the psychologists are interested in a diachronic version. Contact details: j.matheson@unf.edu 1 I have added the name, and have made several small changes to the case. 2 Social Epistemology Review and Reply Collective, 2014 Vol. 3, No. 4, 1-3. http://wp.me/P1Bfg0-Y9 References Conee, Earl. "Evident, but Rationally Unacceptable." The Australian Journal of Philosophy 65 (1987): 316-326. Christensen, David. "Epistemology of Disagreement: The Good News." Philosophical Review 116 (2007): 187-218. Dawson, Erica, Gilovich, Thomas, and Regan, Dennis T. "Motivated Reasoning and Performance on the was on Selection Task." Personality and Social Psychology Bulletin 28, no. 10 (2002): 1379-1387. Elga, Adam. "Reflection and Disagreement." Nous 41 (2007): 478–502. Feldman, Richard . "Reasonable Religious Disagreements" in Louise Antony, ed., Philosophers without Gods: Meditations on Atheism and the Secular Life. New York: Oxford University Press, 2006. Matheson, Jonathan. "Conciliatory Views of Disagreement and Higher-Order Evidence." Episteme: A Journal of Social Philosophy 6, no. 3 (2009): 269-279. Mercier, Hugo. "Reasoning Serves Argumentation in Children." Cognitive Development 26, no. 3 (2011): 177-191. Nickerson, Raymond. "Confirmation bias: A Ubiquitous Phenomenon in Many Guises." Review of General Psychology 2, no. 2 (1998): 175-220.