 The causal basis for \(x\)’s disposition is something like \(x\)’s microstructural property that is or would be causally responsible for the manifestation of that disposition. It will be helpful to have in hand a characterisation of ‘causal basis’ that is more perspicuous than this. In their seminal paper on dispositions, Prior, Pargetter &amp; Jackson (1982) offer the following definition (p. 251):