Traditional approaches view metaphor as a semantic/pragmatic phenomenon that occurs at a conceptual level as mappings between independent concepts. These conceptual mappings are then lexicalized into observed metaphoric expressions. In this view, the lexical and grammatical structure of a metaphoric expression is not relevant to the underlying metaphor’s level of productivity. This paper argues that lexical constraints, ontological constraints, and grammatical constraints are all required to explain the productivity of metaphors. The productivity of metaphor lexicalizations is used to argue for the usefulness of a systematic script-based and ontology-based approach to meaning.