Full Idea
Categories in terms of generality, dependence and containment are unsatisfactory because of the 'cut-off point problem': they don't give an account of how far down the order we can go and be sure we are still dealing with categories.
Gist of Idea
Categories as generalities don't give a criterion for a low-level cut-off point
Source
Jan Westerhoff (Ontological Categories [2005], §27)
Book Reference
Westerhoff,Jan: 'Ontological Categories' [OUP 2005], p.65
A Reaction
I don't see why this should be a devastating objection to any theory. I have a very clear notion of a human being, but a very hazy notion of how far back towards its conception a human being extends.