Full Idea
The category of Venus is not 'physical object' or 'mereological sum', but narrower. Surprisingly, it is not 'planet', since it might cease to be a planet and still merit the name 'Venus'. It is something like 'well-integrated, good-sized physical object'.
Gist of Idea
The category of Venus is not 'object', or even 'planet', but a particular class of good-sized object
Source
Michael Jubien (Possibility [2009], 5.3)
Book Reference
Jubien,Michael: 'Possibility' [OUP 2009], p.136
A Reaction
Jubien is illustrating Idea 13402. This is a nice demonstration of how one might go about the task of constructing categories - by showing the modal profiles of things to which names have been assigned. Categories are file names.
Related Idea
Idea 13402 We only grasp a name if we know whether to apply it when the bearer changes [Jubien]