Aristotle offers apparently inconsistent explanations for paronymous expressions derived from matter: on the received picture, derived from Metaphysics Θ.7, such expressions are used in all and only cases of substantial change, because predicating the matter directly of a substance would be false; on the error picture, derived from Metaphysics Z.7, the same expressions are used in all and only cases of change from an unclear and nameless privation, because ordinary language users conflate such privations with matter. I propose a resolution: (...) the received picture explains why the usage is fitting, but the error picture explains how the usage originated. (shrink)