Full Idea
It is meaningless to talk of the same concrete thing in different possible worlds, ...but it makes sense to speak of the same individual concept, which is just a function which assigns to each possible world in a set an individual in that world.
Gist of Idea
Only concepts, not individuals, can be the same across possible worlds
Source
Allan Gibbard (Contingent Identity [1975], VII)
Book Reference
-: 'Journal of Symbolic Logic' [-], p.208
A Reaction
A lovely bold response to the problem of transworld identity, but one which needs investigation. It sounds very promising to me. 'Aristotle' is a cocept, not a name. There is no separate category of 'names'. Wow. (Attach dispositions to concepts?).