Bayesians often appeal to “merging of opinions” to rebut charges of excessive subjectivity. But what happens in the short run is often of greater interest than what happens in the limit. Seidenfeld and coauthors use this observation as motivation for investigating the counterintuitive short run phenomenon of dilation, since, they allege, dilation is “the opposite” of asymptotic merging of opinions. The measure of uncertainty relevant for dilation, however, is not the one relevant for merging of opinions. We explicitly investigate the (...) short run behavior of the metric relevant for merging, and show that dilation is independent of the opposite of merging. (shrink)

Many political philosophers have held that democracy has epistemic benefits. Most commonly, this case is made by arguing that democracies are better able to track the truth than other political arrangements. Truth, however, is not the only epistemic good that is politically valuable. A number of other epistemic goods – goods including evidence, intellectual virtue, epistemic justice, and empathetic understanding – can also have political value, and in ways that go beyond the value of truth. In this paper, I will (...) survey those who have argued that democracy can be valuable because of these other epistemic benefits, considering (1) the ways in which these epistemic goods can be of political value and (2) the challenges that democracies face in producing them. (shrink)

According to many accounts, propaganda is a variety of politically significant signal with a distinctive connection to irrationality. This irrationality may be theoretical, or practical; it may be supposed that propaganda characteristically elicits this irrationality anew, or else that it exploits its prior existence. The view that encompasses such accounts we will call irrationalism. This essay presents two classes of propaganda that do not bear the sort of connection to irrationality posited by the irrationalist: hard propaganda and propaganda by the (...) deed. Faced with these counterexamples, some irrationalists will offer their account of propaganda as a refinement of the folk concept rather than as an attempt to capture all of its applications. The author argues that any refinement of the concept of propaganda must allow the concept to remain essentially political, and that the irrationalist refinement fails to meet this condition. (shrink)

Psychological studies show that the beliefs of two agents in a hypothesis can diverge even if both agents receive the same evidence. This phenomenon of belief polarisation is often explained by invoking biased assimilation of evidence, where the agents’ prior views about the hypothesis affect the way they process the evidence. We suggest, using a Bayesian model, that even if such influence is excluded, belief polarisation can still arise by another mechanism. This alternative mechanism involves differential weighting of the evidence (...) arising when agents have different initial views about the reliability of their sources of evidence. We provide a systematic exploration of the conditions for belief polarisation in Bayesian models which incorporate opinions about source reliability, and we discuss some implications of our findings for the psychological literature. (shrink)

Predictable polarization is everywhere: we can often predict how people’s opinions, including our own, will shift over time. Extant theories either neglect the fact that we can predict our own polarization, or explain it through irrational mechanisms. They needn’t. Empirical studies suggest that polarization is predictable when evidence is ambiguous, that is, when the rational response is not obvious. I show how Bayesians should model such ambiguity and then prove that—assuming rational updates are those which obey the value of evidence—ambiguity (...) is necessary and sufficient for the rationality of predictable polarization. The main theoretical result is that there can be a series of such updates, each of which is individually expected to make you more accurate, but which together will predictably polarize you. Polarization results from asymmetric increases in accuracy. This mechanism is not only theoretically possible, but empirically plausible. I argue that cognitive search—searching a cognitively accessible space for a particular item—often yields asymmetrically ambiguous evidence, I present an experiment supporting its polarizing effects, and I use simulations to show how it can explain two of the core causes of polarization: confirmation bias and the group polarization effect. (shrink)

Belief polarization is widely seen to threaten havoc on our shared political lives. It is often assumed that BP is the product of epistemically irrational behaviors at the individual level. After distinguishing between BP as it occurs in intra-group and inter-group settings, this paper argues that neither process necessarily reflects individual epistemic irrationality. It is true that these processes can work in tandem to produce so-called “echo chambers.” But while echo chambers are often problematic from the point of view of (...) collective rationality, it doesn't follow that individuals are doing anything wrong, epistemically speaking, in seeking them out. In non-ideal socio-epistemic contexts, echo chamber construction might provide one's best defense against systematic misinformation and deception. (shrink)

There has been a growing interest within analytic philosophy in addressing political and social issues, which has been referred to as the “political turn” in the discipline. The aim of this paper is twofold. First, it discusses the very characterization of the political turn. In particular, it introduces the definition proposed by Bordonaba-Plou, Fernández-Castro, and Torices, suggests that we should not consider the turn a form of activism, and explores an additional benefit of the ideal/nonideal distinction for characterizing the turn. (...) Second, it addresses the concern of what attitude we should take in the face of the different sensitivities we might have with respect to what constitutes an injustice. Which philosophical works should count as part of the political turn? The paper explores three different attitudes toward this dilemma, and favors what it calls the revisionist attitude, which emphasizes the fact that our perception of injustice is subject to error. (shrink)