Devin Lane

Should you defer to individual experts? That is, when a single expert—rather than a group of experts or a expert consensus—testifies that p, should you believe that p? In this paper, I argue that the answer to this question is, generally speaking, “no.” My argument is based on the notion of a complexity‐based defeater. Some questions are complex in a sense that makes inquirers less reliable at answering them. Expert testimony tends to be about such questions. Expert testimony thus tends to be subject to a complexity‐based defeater. The pressing question, then, is whether the speaker's expertise in turn defeats that complexity‐based defeater. I first draw on the extant literature to show why we cannot reliably make case‐by‐case determinations of whether a particular speaker's expertise counteracts the complexity of the particular question they are answering. Next, I argue that a speaker's status as an expert does not, in general, defeat the complexity‐based defeaters that tend to come with expert testimony. We thus should not, generally speaking, defer to individual experts. I then address some issues with the peer review system that are relevant to the core argument. Finally, I briefly discuss a path to rational deference that remains open: a path through expert judgment aggregation.

Several decades of work in both philosophy and psychology acutely highlights our limitations as individual inquirers. One way to recognize these limitations is to defer to experts: roughly, to form one’s beliefs on the basis of expert testimony. Yet, as has become salient in the age of Brexit, Trumpist politics, and climate change denial, people are often mistrustful of experts, and unwilling to defer to them. It’s a trope of highbrow public discourse that this unwillingness is a serious pathology. But to what extent is this trope accurate? Answering this requires us to settle both a normative question—under exactly what conditions ought we to defer to experts?—and an empirical question—under what conditions are people willing to defer to experts? The first question has been investigated primarily by philosophers; the second, primarily by psychologists. Yet there is little work integrating these literatures and putting together their results. The aim of this review article is to begin this task, enabling us to begin reaching conclusions about how much real practices of deference diverge from the ideal. We present an opinionated guide to relevant work from both philosophy and psychology, and note places where the literature has important gaps.

In this paper, I argue that widespread expert disagreement about sufficiently many issues central to a democratic decision-making procedure can nullify the duty to vote. I begin by drawing a distinction between different ways that we might conceive of the duty to vote, i.e. whether it is a duty to vote, no matter how one votes, or a duty to vote well. I then review some prominent arguments in favor of the existence of the duty to vote and suggest that they go through only when the potential voter in question would vote well. So the most promising existing arguments for the duty to vote, if successful, really show not merely that citizens have a duty to vote, but more strongly that they have a duty to vote well. I then discuss the epistemology of expert disagreement to show how circumstances of expert disagreement can nullify such a duty by making it impossible to vote well. To my knowledge, no one has yet brought considerations of the epistemology of expert disagreement to bear on this topic. That is my aim in the main argument of this paper. The remainder of the paper addresses alternative characterizations of ‘voting well’, and argues that on other plausible characterizations, expert disagreement will still often nullify the duty to vote.