Abstract

The difficulties often attributed to prime matter hold for all hylomorphic accounts of substantial change. If the substratum of substantial change actually persists through the change, then such change is merely another kind of accidental change. If the substratum does not persist, then substantial change is merely creation ex nihilo. Either way matter is an empty concept, explaining nothing. This conclusion follows from Aristotle’s homoeomerity principle, and attempts to evade this conclusion by relaxing the constraints Aristotle imposes on elementhood, generation, and substrata all fail, and even the minimal constraints imposed by the Problem of Material Constitution are enough to generate the dilemma. Aristotle resolves this dilemma in Physics I.9 by postulating pure potentiality-for-substance as the substratum of substantial change. Because the substratum persists, substantial change is not creation ex nihilo, but because it does not persist actually it is not a kind of accidental change. Aristotle uses this approach to solve the Problem of the Mixt and the Problem of Material Constitution without weakening his constraints on elementhood, generation, or substrata. This pure potentiality approach must be carefully distinguished from other ‘traditional’ or ‘prime matter’ views that posit some actuality for the substratum of substantial change, and it is best understood in light of the analogy found at Metaphysics Θ.6. Pure potentiality-for-substance can do the work needed in a substratum for substantial change because Aristotle is able to ground the identity, existence, and characterization of the substratum in the corrupting and generating substances rather than the substratum itself.