This sounded kind of crazy when it first popped into my mind.
But I think I've really got the right words this time.

Class of all classes is okay, but it's not part of the physical context
which describes the entity-characteristic-proposition world
external to us. It's part of the epistemology context which
describes how our minds work. In that context you can say
things like

Class subClassOf Resource .
Resource subClassOf Class .
Class is Resource .

But Class is a mental entity, not a physical entity.
You will notice that Class does not appear anywhere in the
CPS hierarchy of

http://ContextKnowledgeSystems.org/kb/spo.rdf.html

Dick McCullough
Context Knowledge Systems
mKE and the mKR language
mKR/mKE tutorial