Full Idea
Worlds are the shadows of our suppositions and they take on their identity from these. Suppositions take on their identity from (inter alia) the objects they relate to. If they sever themselves from these objects, then they collapse.
Clarification
'Inter alia' means among other things
Gist of Idea
Possible worlds rest on the objects about which we have suppositions
Source
David Wiggins (Sameness and Substance Renewed [2001], 4.11)
Book Reference
Wiggins,David: 'Sameness and Substance Renewed' [CUP 2001], p.136
A Reaction
Sounds good. My picture is of possibilities which are suggested by objecfs in the actual world, with extreme possibilities being at fifth-remove from actuality. Any worlds that go beyond natural possibility are just there for fun.