Abstract
The aim of this paper is to offer two novel solutions to two perennial problems of categorial ontology, namely, the problem of the categorial structure: how are the categories related to one another? And the problem of categorial completeness: how is the completeness of a proposed list of categories justified? First, I argue that a system of categories should have a structure such that there is a most basic category that is a bearer of all other categories and that has what I shall call “combinatorial conditions”. To do so, I compare this approach to categorial structure with the approaches given by substantialist, mereological, factualist, and geo ontologies. Second, I argue that the problem of categorial completeness is only a problem for certain ontologies. In this connection, I explore views on categorial completeness proposed by substantialists and geo-ontologists. Lastly, I conclude that factualism does a better job of accounting for categorial structure and categorial completeness than other categorial ontologies.