What constitutes an ontological category, and how should these classifications be understood in relation to the structure of reality? Jan Westerhoff, a scholar of philosophy, examines the historical and contemporary definitions of ontological categories to address the ambiguity surrounding their application in metaphysical discourse. He argues that these categories should be viewed as systematizations of human knowledge rather than as inherent, essential properties of the world itself, thereby shifting the focus from objective reality to the conceptual frameworks used to organize it.

Experts recognize this work as a foundational text for those seeking to clarify the conceptual underpinnings of metaphysical inquiry. Readers frequently note the academic density of the prose, which is intended for advanced students and professional philosophers.