 First, consider substratum. (i) Ontological basicness. There is a sense in which it is ontologically basic, but it is a rather empty sense: it is the substancehood of everything, without explaining the nature of anything. (ii) Durability. Again, it meets the criterion, but in an empty way. It is difficult to see how it could be destroyed (like Aristotle’s prime matter) but it has no positive nature. (iii) and (iv) Bearer of predication and subject of change. As with matter for Aristotle, it meets the first of these standards well, but, in so far as it is a component only in atoms, it is not the subject of change. (v) and (vi) Kinds of individuals and stuffs. Although in everything, it is itself no kind of thing and therefore no kind of individual or stuff. Substratum’s claim to substancehood does not rest, however, on meeting the tests itself, but on being what enables particular kinds of substances to be substances. According to the believer in substratum, it is in virtue of their inhering in a substratum that a collection of properties can constitute an enduring, change-sustaining thing of a certain kind. Without that support, individual instances of properties could, if they could exist at all, be no more than ephemeral events.