Full Idea
The whole identity of a part is relevant to whether it is a part, but the identity of the whole makes a part a part. The whole part belongs to the whole as a part. The standard account in terms of time-slices fails to respect this part/whole asymmetry.
Gist of Idea
Part and whole contribute asymmetrically to one another, so must differ
Source
Kit Fine (Things and Their Parts [1999], §2)
Book Reference
-: 'Midwest Studs in Philosophy' [-], p.65
A Reaction
Hard to follow, but I think the asymmetry is that the wholeness of the part contributes to the wholeness of the whole, while the wholeness of the whole contributes to the parthood of the part. Wholeness does different jobs in different directions. OK?