Abstract
Enterprise Architecture (EA) description frameworks embody a "worldview" which is used by architects to conceptualize the enterprise and its elements. This "worldview" manifests itself in the choice of language constructs and in modeling rules and guidelines, and, whether explicitly or not, reflects some foundational ontological choices. This paper reflects on the practical consequences of some of these choices. We focus on the capability-related elements in EA defense frameworks (DoDAF, MODAF and NAF). In particular, we analyse the support for modeling capabilities in these frameworks from the prism of a fundamental distinction in formal ontology: two-category vs. four-category ontology. By analyzing the current choices in these frameworks and identifying some adverse consequences, we are able to suggest well-founded recommendations for improvements.