This is a meta-level predicate for distinguishing very
general classes, which in the analytic philosophy literature are taken to be 'uncountable'
(cf. Griffin, 1977: a part of something belonging to the class c belongs to c as well;
in other terms, an instance of a category class is internally homogeneous).
A problem is that such a description is applicable to 'mass' objects (a piece of
gold, an amount of water, etc.) as well, which are not exactly very general in the
Cognitive semantics provides us a criterion for further intuition: a category
class is (cognitively) reidentifiable by means of a single image-schema (container,
path, etc., cf. Mark Johnson, 1989), while masses are reidentified on the basis
of material properties.
Another way for distinguishing masses from categories at meta-level is granularity (see theory:
layers): a mass has homogeneous parts as far as the same granularity (or an adjacent one)
is maintained: for example, a part of a piece of gold is gold until the atomic granularity,
but not at sub-atomic granularity; a part of a food is the same food till molar granularity,
but not at molecular granularity, etc.
- Subclass-Of: Structural-concept
(Inherited-Slot-Value Category The-Archetype Category)
(=> (Category ?Self)
(Forall (?Homog ?X ?Y)
(=> (And (Isa ?Homog Entity)
(Instance-Of ?X ?Self)
(Instance-Of ?Y ?Homog)
(Part-Of ?Y ?X))
(Identity ?Self ?Homog))))