Full Idea
We can expect that, for every completely determinate continuant, there will be at least one sortal concept that it falls under and that determines a principle of persistence for it.
Gist of Idea
Every determinate thing falls under a sortal, which fixes its persistence
Source
David Wiggins (Sameness and Substance [1980], 2.4)
Book Reference
Wiggins,David: 'Sameness and Substance' [Blackwell 1980], p.60
A Reaction
I think he has the 'determines' relation the wrong way round! Being a tiger doesn't determine anything about persistence. It is having that nature and those persistence conditions which make it a tiger. And why does he optimistically 'expect' this?