Core classification theory: a reply to Szostak

Purpose – The purpose of this paper is to provide an answer to a critique put forward by Szostak against a paper written by the present author. Design/methodology/approach – The paper is based on a literature‐based conceptual analysis based on Hjørland and Nissen Pedersen and Szostak. The main points in a core theory of classification are outlined and Szostak's criticism is examined and answered. Findings – The paper demonstrates theoretical differences between the views adduced by Hjørland and Nissen Pedersen on the one side and by Szostak on the other. Practical implications – Theoretical clarification is important for the future development of the field. Originality/value – The paper should be seen as one among others developing an argument for a theoretical foundation of classification informed by the theory of knowledge.