Full Idea
We have not finished deciding what Fido is when we can pick him out from his surroundings at any one time. ...Knowing what Fido is depends on knowing roughly within what limits his flux of parts is tolerable.
Gist of Idea
To individuate something we must pick it out, but also know its limits of variation
Source
Peter Simons (Parts [1987], 5.2)
Book Reference
Simons,Peter: 'Parts: a Study in Ontology' [OUP 1987], p.186
A Reaction
I like this. We don't know the world until we know its modal characteristics (its powers or dispositions). Have you 'individuated' a hand grenade if you think it is a nice ornament?