Dispositions, conditionals and auspicious circumstances

A number of authors have suggested that a conditional analysis of dispositions must take roughly the following form: Thing X is disposed to produce response R to stimulus S just in case, if X were exposed to S and surrounding circumstances were auspicious, then X would produce R. The great challenge is cashing out the relevant notion of ‘auspicious circumstances’. I give a general argument which entails that all existing conditional analyses fail, and that there is no satisfactory way to define ‘auspicious circumstances’ just in terms of S, R, and X. Instead, I argue that the auspicious circumstances C for the manifestation of a disposition constitute a third irreducible element of that disposition, and that to pick out (or to ‘individuate’) that disposition one must specify C along with S and R. This enables a new conditional analysis of dispositions that gives intuitively satisfying answers in cases that pose problems for other approaches.