Beliefs, buses and lotteries: Why rational belief can’t be stably high credence

Abstract

Until recently, it seemed like no theory about the relationship between rational credence and rational outright belief could reconcile three independently plausible assumptions: that our beliefs should be logically consistent, that our degrees of belief should be probabilistic, and that a rational agent believes something just in case she is sufficiently confident in it. Recently a new formal framework has been proposed that can accommodate these three assumptions, which is known as ''the stability theory of belief'' or ''high probability cores.'' In this paper, I examine whether the stability theory of belief can meet two further constraints that have been proposed in the literature: that it is irrational to outright believe lottery propositions, and that it is irrational to hold outright beliefs based on purely statistical evidence. I argue that these two further constraints create a dilemma for a proponent of the stability theory: she must either deny that her theory is meant to give an account of the common epistemic notion of outright belief, or supplement the theory with further constraints on rational belief that render the stability theory explanatorily idle. This result sheds light on the general prospects for a purely formal theory of the relationship between rational credence and belief, i.e. a theory that does not take into account belief content. I argue that it is doubtful that any such theory could properly account for these two constraints, and hence play an important role in characterizing our common epistemic notion of outright belief.

The relationship between belief and credence

“…On a third view, the norms for each attitude are independent: maybe the norms for credence are probabilistic coherence and updating by conditionalization, and the norms for belief are deductive consistency (Frankish, 2009, p. 80; Weisberg, 2015). Relatedly, several authors have argued that rational belief and rational credence are sensitive to different features of a body of evidence, so, for example, one could rationally have a high credence in p, but should not believe p (see Buchak, 2014; Friedman, 2013; Jackson, 2019c, Forthcoming; Smith, 2010b, 2016; Staffel, 2015). We will return to fundamentality later, but now examine arguably the most widely‐discussed normative connection between belief and credence: the Lockean thesis.…”

Explaining enkratic asymmetries: knowledge-first style

“…This is primarily due to considerations of space. For there is significant reason to think outright belief and credences, while related, are distinct and that their rational statuses may not systematically vary (Wedgwood 2012;Buchak 2013;Staffel 2016;cf. Weisberg forthcoming).…”

A bitter pill for closure

“…The former requires rejecting (ST), while the latter requires rejecting (MPC). Proponents of the first strategy include Ryan (1996), Kaplan (1996), Nelkin (2000), Leplin (2009), Buchak (2014, Staffel (2016), and Smith (2010Smith ( , 2016. Proponents of the second strategy include Kyburg (1961), Foley (1992), David (2004, and Sturgeon (2008).…”