ABSTRACT
In this chapter I discuss to what extent Nancy Cartwright’s appeal to John Stuart Mill’s use of “tendencies” to defend or motivate her central notion of “capacity” is justified. My observations are meant to shed some light on the relation between these two concepts rather than to criticize or defend either, and so I shall argue that the differences between Mill and Cartwright are more significant than Cartwright’s writings suggest. This need not be seen as a fundamental problem for Cartwright, as she has a number of other, independent arguments to defend her claim that capacities should be taken to be the fundamental building blocks of the natural and social sciences; it simply shows that she should probably not appeal to Mill to support this claim. In any case, Mill’s concept of “tendencies” is also problematic: It is not clear whether it squares well with his empiricist account of laws.
