Full Idea
Categories are usually not assumed to be ordered by containment, but also be generality.
Gist of Idea
Categories can be ordered by both containment and generality
Source
Jan Westerhoff (Ontological Categories [2005], §02)
Book Reference
Westerhoff,Jan: 'Ontological Categories' [OUP 2005], p.19
A Reaction
I much prefer generality, which is responsive to the full picture, whereas containment seems to appeal too much to the orderly and formalised mind. Containments overlap, so we can't dream of a perfectly neat system.