Formal ontology relies on representation languages for expressing ontologies. This involves the formal semantics of these languages which is typically based on a limited set of abstract mathematical notions. In this paper, we discuss the interplay between formal semantics and the intended role of ontologies as semantic foundation. In this connection a circularity is identified if ontologies are to determine the conceptual equivalence of expressions. This is particularly relevant for ontologies which are to be provided in multiple formalisms. In order to overcome this situation, ontological semantics is generally defined as a novel kind of semantics which is purely and directly based on ontological entities. We sketch a specific application of this semantics to the syntax of first order logic. In order to beneficially rely on theoretical results and reasoning systems, an approximation of the proposed semantics in terms of the conventional approach is established. This results in a formalization method for first order logic and a translation-based variant of ontological semantics. Both variants involve an ontology for their application. In the context of developing a top-level ontology, we outline an ontology which serves as a meta-ontology in applying ontological semantics to the formalization of ontologies. Finally, resolved and remaining issues as well as related approaches are briefly discussed.