 Of course, modal interpretations admit a trivial dynamics, namely, one in which there is no correlation from one time to the next. In this case, the probability of the transition from the property \(P\) having the actual value \(\alpha\) at \(t_0\) to the property \(P'\) having the actual value \(\beta\) at \(t_1 \gt t_0\) is just the single-time probability for \(P'\) having \(\beta\) at \(t_1\). However, this dynamics is unlikely to interest those who feel the need for a dynamics at all. Several researchers have contributed to the project of constructing a more interesting form of dynamics for modal interpretations (see Vermaas 1996, 1998). An important account is due to Bacciagaluppi and Dickson (1999, see also Bacciagaluppi 1998). That work shows the most significant challenges that the construction of a dynamics of actual properties must face.