Knowledge and Ability Externalism

Contemporary alternatives to belief-based accounts of knowledge include, among others, accounts of knowledge as a mental state, such as Williamson's (2000), and ability-based accounts of knowledge such as those defended by Hyman (2015) and Hetherington (2011). Smith (2017) has argued that a cost of endorsing the thesis that knowledge is a mental state is that doing so commits us to an unfamiliar (and perhaps radical) form of externalism about the mental. Here I argue that we are already committed to just this kind of externalism in our thinking about an agent's abilities and that there is no analogous cost to endorsing the thesis that knowledge is an ability.