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 meet