e may give a semantics for ability-ascriptions that does not quantify over abilities themselves. This is arguably the main theme of the hypothetical theories to be considered in Section 3, and the modal theories to be considered in Section 4. Given this tendency in thinking about ability, an overview of philosophical work on ability that neglected the role of ability-ascriptions would be seriously incomplete.
There is also the second, more philosophical, reason. Any account of abilities owes us, among other things, an account of ability-ascriptions. This is perhaps true of philosophical topics generally, but it is true of ability in particular. Even philosophers who are explicit in their ‘refusal to take language as a starting point in the analysis of thought and modality’ (Lewis 1986, xi) are prone to make explicit appeal to language when the topic turns to ability, as occurs in (Lewis 1976) or (Taylor 1960). This is for any number of reasons, but perhaps especially because it is difficult to even identify the topic under consideration without using or mentioning certain phrases, notably ‘can’ and ‘is able to.’
Happily, the topic of ability-ascriptions is one on which linguists and philosophers have made significant progress. While there has long been considerable philosophical interest expressions such as ‘can’ and ‘is able to,’ there is nothing recognizable as a rigorous semantic theory of such terms prior to the foundational work of Angelika Kratzer, recently revised and collected in (Kratzer 2012). Kratzer’s work has been central to natural language semantics, and its significance for philosophical work is still being appreciated. The question of whether it is correct as an account of the semantics of agentive modality is an open one: important challenges include (Hackl 1998) and, more recently, (Mandelkern, Schultheis, and Boylan, 2017), (Schwarz 2020), and (Willer forthcoming). The Kratzer semantics, and a view of ability on which that semantics plays a foundational role, will be considered in some detail in Section 4. The more methodological point being made here is that any adequate account of ability ought to provide an account of ability-ascriptions, and as such may want to reckon with this ongoing debate in the semantics of modal expressions.
The bulk of theories of ability that have been defended in the historical and contemporary literature have been what we might call hypothetical theories. On such views, to have an ability is for it to be the case that one would act in certain ways if one were to have certain volitions. One arrives at different theories depending on how one understands the volitions in question and how exactly these actions would hypothetically depend on them, but nonetheless these views constitute something like a unified family. Given their prominence and unity, it is natural to begin our survey of theories of ability with them.
The most prominent hypothetical theory of ability is what has come to be called the ‘conditional analysis’. In this section, we will survey that form of analysis, the problems for it, and alternatives to it that are supposed to overcome those problems.
The conditional analysis of ability has at least two aspects. First, S has an ability to A just in case a certain conditional is true of her. Second, that conditional has the following form: S would A if S were to have a certain volition. The precise form such an analysis will take will depend on, first, how we interpret this conditional and, second, which volition figures in the antecedent.
It has been standard in the literature, when this first question has been raised, to understand the conditional as a subjunctive conditional (Ginet 1980), and we will assume in what follows that this is the best form of the conditional analysis. There has been some disagreement about whether it is a might or a would conditional that is relevant (for an account of this distinction, see Lewis 1973, 21–24), as well as about which volition is relevant. In the following, we will take the relevant conditional to be a would condition