Full Idea
A wave is not a 'jealous' event. Lives, however, are jealous. It cannot be that the activities of the Xs constitute at one and the same time two lives. Only in certain special cases can two lives overlap.
Gist of Idea
Unlike waves, lives are 'jealous'; it is almost impossible for them to overlap
Source
Peter van Inwagen (Material Beings [1990], 09)
Book Reference
Inwagen,Peter van: 'Material Beings' [Cornell 1995], p.89