 We will not here consider cases of probabilistic dispositions; the ‘surefire’ or deterministic cases are difficult enough. A clarification is needed of the concept of causally operative sufficient condition. One thing we can say for sure about it is that a condition is causally operative sufficient for some effect only if, given the laws of nature, whenever the condition is present it is causally necessary that the effect occurs. PPJ then entails the following account of causal basis: a causal basis for \(D\) is a property or property-complex \(P\) such that, given the laws of nature, whenever an object \(x\) has \(P\) and undergoes the characteristic stimulus of \(D\), it is causally necessary that \(x\) exhibits the characteristic manifestation of \(D\). Nolan (2015) suggests that a link between the characteristic stimulus and manifestation of \(D\) doesn’t need to be a causal one, and then criticises PPJ on the ground that it presupposes such a causal link. (For another criticism of PPJ, see Contessa 2012.)