Full Idea
Being caught up in the life of an organism is, like being rich or being tall, a matter of degree, and is in that sense a vague condition.
Gist of Idea
Being part of an organism's life is a matter of degree, and vague
Source
Peter van Inwagen (Material Beings [1990], 17)
Book Reference
Inwagen,Peter van: 'Material Beings' [Cornell 1995], p.217
A Reaction
Van Inwagen is trying to cover himself, given that he makes a sharp distinction between living organisms, which are unified objects, and everything else, which isn't. There may be a vague centre to a 'life', as well as vague boundaries.