Daniel Kilov

ABSTRACT Wilfrid Sellars [1962: 1] described philosophy as an attempt to ‘understand how things in the broadest possible sense of the term hang together in the broadest possible sense of the term’. But it is distinctive of philosophy that many of us are interested not only in how the world is but in ways that it could be. That is, philosophy is concerned with facts about modality. Some of the most important arguments in philosophy hinge on modal premises, and philosophers have typically assumed special expertise in evaluating these modal premises. Replicating Goldvarg and Johnson-Laird’s [2000] study of modal illusions, we show that training in mathematics and not philosophy predicts success in overcoming such illusions (n = 395). This study is the first to test the modal expertise of professional philosophers directly. Our findings undermine claims to modal expertise. Philosophical training does not inoculate expert philosophers against basic mistakes in modal judgment.

Buoyed by research in philosophy and moral psychology, virtue ethics has become increasingly influential in the literature. This renewed attention has also led to the development of the situationist challenge: empirical studies undermine the idea that we possess character traits that allow us to act virtuously across contexts. A promising reply to the situationist challenge is that we should not conceive of virtues as traits. Instead, we should conceive of them as expert skills. Here, I raise a new challenge for those who go in for the (s)kill against situationism. Expert skills are brittle, rather than flexible or robust. They typically develop in narrow ways and can falter in novel situations. Experts also sometimes perform worse than novices in novel situations. Such findings present a problem for the virtue-as-skill thesis. Someone who will help others only in narrow contexts or who causes more harm than good does not exemplify virtue. The brittleness of expert skills means that virtue theorists must either (a) abandon the idea that virtues explain behaviour across contexts or (b) abandon the idea that virtues are expert skills. It’s brittle virtue or bust – you can’t teach an old dogma new skills.

Wilfrid Sellars [1962: 1] described philosophy as an attempt to ‘understand how things in the broadest possible sense of the term hang together in the broadest possible sense of the term’. But it is distinctive of philosophy that many of us are interested not only in how the world is but in ways that it could be. That is, philosophy is concerned with facts about modality. Some of the most important arguments in philosophy hinge on modal premises, and philosophers have typically assumed special expertise in evaluating these modal premises. Replicating Goldvarg and Johnson-Laird’s [2000] study of modal illusions, we show that training in mathematics and not philosophy predicts success in overcoming such illusions (n = 395). This study is the first to test the modal expertise of professional philosophers directly. Our findings undermine claims to modal expertise. Philosophical training does not inoculate expert philosophers against basic mistakes in modal judgment.

Expertise has become a topic of increased interest to philosophers. Fascinating in its own right, expertise also plays a crucial role in several philosophical debates. My aim in this paper is to draw attention to an important, and hitherto unappreciated feature of expertise: its brittleness. Experts are often unable to transfer their proficiency in one domain to other, even intuitively similar domains. Experts are often unable to flexibly respond to changes within their domains. And, even more surprisingly, experts will occasionally be outperformed by novices when confronted with novel circumstances within their domains of expertise. In section 1, I marshal the evidence in favour of brittleness. In section 2, I argue that appeals to brittleness can advance the dialectic in debates on skilled action and provide reasons to reject a powerful recent argument offered by Christensen et al. : 693–719, 2019). In section 3, I appeal to brittleness to argue against a common conception of philosophical expertise, according to which philosophers possess a domain-general set of reasoning skills. Although my argument in this section is largely negative, there is a twist. Recalibrating our understanding of philosophical expertise opens new avenues of research for defenders of the so-called ‘expertise defence’ against the findings of experimental philosophy.