The bare metaphysical possibility of bare dispositions (causal basis)

Many philosophers hold that all dispositions must have independent causal bases. I challenge this view, hence defending the possibility of bare dispositions. 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.