Towards a Substance-Theory of Substance

Abstract

For the past three chapters, we have been examining two accounts of the ontological structure of substances. According to one, substances are wholes whose constituents are simply properties; whereas, the other account takes substances to incorporate an additional constituent, a substratum. Now, for epistemological reasons, we were initially inclined to accept the bundle theorist’s account of substance; but we found the substratum theorist pointing to four supposed flaws in the bundle theory, each of which, he claimed, could be overcome only by the appeal to a substratum ontology. The first difficulty was that since substances are contingent beings, they cannot be constituted exclusively by necessary beings. According to the substratum theorist, the contingency of ordinary objects is accounted for only if we admit among their constituents entities that are themselves contingent — substrata. The second difficulty was that the bundle theorist cannot account for identity through change; the possibility of identity through change, we were told, presupposes that each substance incorporates among its constituents a principle of permanence — again, a substratum. The third difficulty was that the bundle theorist is forced to construe all true sentences in which we attribute properties to substances as tautological; to explain the non-tautological truth of such sentences, the substratum theorist insisted that we take substances to incoporate a constituent which, while capable of serving as the possessor of properties, is ontologically independent of the properties which can be predicated of it; and once again the additional constituent was identified with substratum.