Formal Ontology = Taxonomy + Knowledge Base + Grammar + ??

If you take the ideas behind a taxonomy (taxonomical classes, hypernyms, hyponyms, related ideas, hierarchy of concepts), plus the components of a knowledge base (a long list of enumerations satisfying the various classes of the taxonomy), plus a grammar (rules defining morphology, syntax, and semantics) you have a good start as to what an ontology is. But what is missing?

My current working definition for the missing part is this: The explicit and rigorous definition of the elements of the taxonomy, the knowledge base, and the grammar, as well as rules defining the relationships among the various components.

Tags: ontology, taxonomy, knowledge base, grammar