Date of this Version
Philosophy and Phenomenological Research Vol. LXVI, No. 2, March 2003
When people ask why something produces a certain effect, they are often looking for a deeper explanation than just "because it is disposed to produce that effect." The inability to produce a deeper explanation, on this view, reflects ignorance or a failure of understanding. It is supposed that there must be something other than the disposition that causally explains the manifestation, or to use terminology that is now common, every disposition must have a distinct "causal basis." There is something puzzling about the idea of a bare disposition--a disposition that has no distinct causal basis. Some have argued that the very idea of a bare disposition is incoherent. However, I disagree. Bare dispositions are possible. Moreover, it is an open question whether any objects have bare dispositions in this world.
Significantly, bare dispositions figure in larger metaphysical programs, for example, the phenomenalist view that matter is the "permanent possibility of sensation." More recently, some philosophers have defended the view that the fundamental properties of the ultimate constituents of matter are dispositional. On these views, the world abounds with bare dispositions. On some other views, there are no bare dispositions. For example, according to Lewis' "Humean supervenience," everything that is true about the world supervenes on "a vast mosaic of local matters of particular fact." I take it that, on this view, these local matters of particular fact are not dispositional. It follows that, if the world contains bare dispositions, Humean supervenience is false. Clearly, a defense of bare dispositions has broad philosophical significance.
My defense will proceed as follows. In part 1, I explain more fully what I mean by "disposition," "causal basis," and "bare disposition." In part 2, I consider the claim that the concept of a disposition entails that dispositions are not bare. In part 3, I consider arguments, due to Prior, Pargetter, and Jackson, that dispositions necessarily have distinct causal bases. In part 4, I consider arguments by Smith and Stoljar that there can't be bare dispositions because they would make for unwelcome "barely true" counterfactuals. In the end, I find no reason to deny the possibility of bare dispositions.