Recent work by Alfred Mele, Romy Jaster and Chandra Sripada recognizes that abilities come in degrees of fallibility. The rough idea is that abilities are often not surefire. They are liable to fail. The more liable an ability is to fail, the more fallible it is. Fallibility is plausibly significant for addiction, responsibility, and normative theorizing. However, we lack an adequate account of what fallibility consists in. This article addresses that problem. Perhaps the most natural approach is to say (roughly) (...) the fallibility of your ability to F is the proportion of scenarios in which you do not F, among those in which you try to F. I argue that this approach (in all plausible versions) is mistaken. I then introduce the notion of an action’s “fragility,” and propose that we use that new notion to understand fallibility. (shrink)

Abilities, in contrast to mere dispositions, propensities, or tendencies, abilities seem to be features of agents that put the agent herself in control. But what is the distinguishing feature of abilities vis‐à‐vis other kinds of powers? Our aim in this paper is to point, in answer to this question, to a crucial feature of abilities that existing accounts have tended to neglect: their adaptivity. Adaptivity is a feature of how abilities are exercised. The main reason for its relative neglect has (...) been that most extant accounts have focused solely on whether abilities are exercised successfully in certain possible situations and have mostly understood the exercise of an ability in terms of complete successful performance. We begin by pointing out two aspects of abilities with regard to which current accounts seem (at best) incomplete: control and exercise. We then introduce adaptivity as we understand it, and end by putting it to work in developing a fuller understanding of abilities that does better than current accounts. (shrink)