What is an adequate philosophy for knowledge management for an ontologist working in information science? I will contend that the relevant part of knowledge management, namely the theory of knowledge representation, lacks proper foundations. In particular, I will criticize the traditional philosophical approach to knowledge representation, which I call pragmatist conceptualism. I argue on the one hand that its emphasis on pragmatism falls short of providing a reflective and principled methodology, and that on the other hand conc
eptualism is doomed by its neglect of reality. This paper outlines and defends a clear standpoint of philosophical realism together with a commensurate methodology for the task of the knowledge engineer.