 For the problem of General Semantic Interoperability, some form of foundation ontology ('upper ontology') is required that is sufficiently comprehensive to provide the definition of concepts for more specialized ontologies in multiple domains.Over the past decade, more than ten foundation ontologies have been developed, but none have as yet been adopted by a wide user base.The need for a single comprehensive all-inclusive ontology to support Semantic Interoperability can be avoided by designing the common foundation ontology as a set of basic ("primitive") concepts that can be combined to create the logical descriptions of the meanings of terms used in local domain ontologies or local databases.