Abstract

This paper deals with the Aristotelian notion of topical matter mentioned in a few passages of the Metaphysics and ascribed to the celestial bodies. Taking into account the metaphysical context of each occurrence of this notion, it tries to determine for what metaphysical use this notion has been developed and what impact it has on the ousiological analysis of the celestial substances. It suggests that the notion of topical matter, although intended to provide a convenient tool that makes possible a metaphysical, i.e. universal study of sensible substances, by allowing to subordinate every sensible substance to similar principles, in fact prevents celestial substances from being defined as ordinary hylomorphic compounds and leads to conceive them as a particular type of substances.