 On an interventionist construal,  (4)  is unpacked as a claim to the effect that under some possible intervention that changes \(S_t\), there would be an associated change in \(S_{t+d}\). This raises the worry that it is unclear what would be involved in such an intervention (given that there is nothing in addition to \(S_t\) that might realize the intervention) and unclear how to assess what would happen if it were to occur, given the stipulation that \(S_t\) is a specification of the entire state of the universe. 