Abstract

Recently there has been a surge of interest in the intersection between epistemology and action theory, especially in principles linking rationality in thought and rationality in action. Recently there has also been a surge of interest in the epistemic significance of perceived peer disagreement: what, epistemically speaking, is the rational response in light of disagreement with someone whom one regards as an epistemic peer? The objective of this paper is to explore these two issues—separately, but also in connection with one another. I turn first to the idea that the normative standing of our actions depends on the normative standing of our beliefs. I endorse this idea. More precisely, I endorse a principle according to which sufficiently high credence in success conditions for a given goal-directed action is a necessary condition on rational execution of that action. I then turn to the debate concerning the epistemic significance of perceived peer disagreement. The basic issue is whether such disagreement is always epistemically significant in the sense of serving as a defeater of the initial credences of the disagreeing parties. Conformists argue that this is so while non-conformists deny it. I present a new argument against a brand of non-conformism that I call “strong non-conformism”. The key premise is the principle that sufficiently high credence in success conditions for a given goal-directed action is a necessary condition on rational execution of that action. I argue that, given this principle, strong non-conformism fails to yield the verdict that the epistemic requirement on rational action is violated in a case where, intuitively, it is violated. This is because strong non-conformism has it that disagreement with a perceived peer does not act as a defeater in the relevant case. Conformism fares better.