 One possible rejoinder to this argument is that it turns on an equivocation in the meaning of “matter”. As we have seen, for Aristotle matter comes in different levels. In the situation envisaged Socrates and Callias would have the same remote or low-level matter (the same elements) but they might still have different proximate matter, since the proximate matter of a human being is his body. Since a substance is a compound of a substantial form and some proximate matter, we are not entitled to conclude that Socrates and Callias are the same. Although this may be an effective way of dealing with the initial problem, it can be restated so as to avoid this objection that the argument equivocates on “matter”. Each level of matter is a compound of the matter at the level immediately below it and a form. If the proximate matter of two things is to be different, despite their lower-level matter being the same, the reason must be that the forms of the proximate matters are different. We can redescribe the situation so that not only are Socrates’ and Callias’ forms the same, but the forms of their bodies are also the same, and the forms of the matter of their bodies, and so on all the way down. Although it is unclear what in general is required for the matter of two things of the same form to have the same form, e.g., for Socrates’ and Callias’ bodies to have the same form, it seems reasonable to suppose that it is sufficient for two things to have the same form that they be qualitatively the same. So we can ensure that Socrates’ and Callias’ matters have the same form, if we suppose that they are qualitatively the same. One might insist that no two things are qualitatively the same, but there is little reason to think that Aristotle is committed to Leibniz’s doctrine of the identity of indiscernibles. What is more, although strict qualitative identity, i.e., having all the same non-relational and relational properties, may require demanding metaphysical assumptions such as an eternally cyclic universe, probably all that is required is that there be no relevant qualitative difference between Socrates and Callias, where “relevant” means such as to result in them or their matter having different forms. While one might insist that two things must be qualitatively the same to have the same form, this also does not seem to be Aristotle’s view. So if we tailor our example to this requirement, we can thwart the charge of equivocation. The argument then is valid, so we must choose one of its premises to reject.