A Meta-ontological Architecture for Foundational Ontologies Heinrich Herre and Frank Loebe Research Group Ontologies in Medicine (Onto-Med), Institute of Medical Informatics, Statistics, and Epidemiology (IMISE) and Institute of Informatics (IfI), Leipzig University, Germany {herre,loebe}@informatik.uni-leipzig.de http://www.onto-med.de Abstract. In this paper we present and discuss a meta-ontological archi- tecture for ontologies which centers on abstract core ontologies (ACOs). An ACO is the most abstract part of a foundational ontology. It is useful for an ontologically founded description of ontologies themselves, there- fore ACOs are lifted to the meta-level. We propose a three-layered meta- ontological architecture which distinguishes an object level comprising foundational, generic or domain-specific ontologies, a meta-level with abstract core ontologies, and a meta-meta-level employing abstract top ontologies for the formalization of the underlying levels. Moreover, two axiomatic fragments for ACOs are provided, one of which is applied to formal concept lattices [1]. This demonstrates the use of ACOs for the ontological foundation of representation formalisms and illustrates ad- vantages in comparison to the usual direct formal reduction to set theory. Finally, related work with respect to the architecture is briefly discussed. 1 Introduction There is a rapidly growing body of work on ontologies in information systems over the last 10 to 15 years, which has been boosted by the vision of the Seman- tic Web. Likewise, research in formal tools and techniques related to ontology development (or ontological engineering ) is very active. By Grubers definition of ontologies as sharable conceptual specifications [2], their development is an issue closely related to the field of conceptual modeling. From the very beginning, ontologies were distinguished according to their intended range of applicability. In particular, foundational ontologies 1 were con- sidered to provide the most general kinds of entities as a basis for more specific ontologies. However, work on foundational ontologies has resulted in rather large and complex systems. This is problematic if foundational ontologies are to be applied to identify and express ontological commitments of representation for- malisms. 1 Also referred to as top-level ontologies in the literature; examples are: DOLCE [3], GFO [4], SUMO [5], and Seibt’s [6], Sowa’s [7] and West’s [8] ontologies R. Meersman and Z. Tari (Eds.): CoopIS/DOA/ODBASE 2005, LNCS 3761, pp. 1398–1415, 2005. c  Springer-Verlag Berlin Heidelberg 2005