Take a Person for example, with subclasses
Boy and Man. [MW>]
The main problem with this is that Boy and Man are not
subtypes of person. For Boy and Man to be subtypes of
Person, each Boy is a Person, and each Man is a (different)
Person. What would be correct is that Boy and Man a subtypes
of StateOfPerson, and that each StateOfPerson is a
temporalPart of a Person.
To most people, and dictionaries, Boy and Man are subtypes of
Person. Second, should a KB contain both a Boy & Man resource
about a given individual, owl:sameAs would be used to indicate their
equivalence otherwise, yes, they would be a different person, as
they should be. Third, StateofPerson is a wholly artificial term,
lacking both practical merit and semantic credibility. Fourth, this
is a fine example of ontologists' implicit saintliness modelling
'concepts' not 'language'.