First we begin with a brief description of the process of information modeling followed by a very brief discussion of earlier attempts to address the philosophical foundations. Then we introduce four concepts from metaphysics that are highly relevant to information modeling. These four concepts are as old as philosophy itself and yet when applied to information modeling, they are as relevant to database design as they were to philosophers over the past few millennia. These four concepts are (a) the concept of identity, (b) the problem of universals, (c) teleology, and (d) the correspondence vs. coherence views of truth. Each concept will be explained in turn, as will its implications for information modeling. Each of these concepts also provides a foundation from which a theory of information modeling and, eventually, a theory of information systems can be built. So, following the introduction of the concepts, we will explain how they were identified.