Their Nature and Significance
Oxford University Press, 2005
Hardback £35.00 ISBN 0-19-928504-7
The concept of an ontological category is central to metaphysics. Metaphysicians argue about which category an object should be assigned to, whether one category can be reduced to another one, or whether there might be different equally adequate systems of categorization. Answers to these questions presuppose a clear understanding of what precisely an ontological category is, an issue which is rarely addressed. This book presents the first in-depth analysis both of the use made of ontological categories in the metaphysical literature, and of various attempts at defining them. It also develops a new theory of ontological categories which implies both that there is no unique system of such categories, as well as that the ontological category an object belongs to is not an essential property of that object. Systems of ontological categories are structures imposed on the world, rather than reflections of a deep metaphysical reality already present.
Stephen McLeod in Philosophy in Review, 28, 4, 2008 , 306-308.
Panayotis Butcharov in The Philosophical Quarterly, 57, 227, 2007, 301-303.
Andrea Borghini in Rivista di Recensioni Filosofiche, 3, 2006-2007, 113-124.