Knowing the powers

If the world contains primitive modal elements—irreducible laws, powers, potentialities, or propensities—how could we know about them? Humeans have long worried that we could not. If modal phenomena are reducible to facts about occurrent events, then it is no surprise that observing occurrent events can give us information about modality. By contrast, knowledge of primitive modality seems to require an inexplicable leap from observations of one kind of fact to conclusions about an entirely different kind of fact. Let’s call this the access problem for non-Humean accounts of (natural) modality. In its blunt formulation, the access problem is easy to resist. Arguably, some modal facts can be directly observed. In other cases, inference to the best explanation might be hoped to get us from, say, an observation of frequencies to hypotheses about chance. Like many Humeans, this chapter’s author is not convinced by these replies, thinking they do not get to the heart of the access problem. The aim of the chapter is to explain why.