In Chapter 2 we raised the question of whether Aristotle thinks that in all cases of coming-to-be (including substantial generation) the subject from which the change proceeds must persist through that change or whether he thinks this holds only for those cases where S comes to be F in the qualified sense. I tried to show that, if Aristotle did think that in cases of substantial generation the pre-existing matter survives to become a constituent of the finished product, it is not obvious that he provides that defence in Physics I as the standard reading assumes. However, because the idea of persistent matter has such a firm hold on the literature, much more will be needed to loosen its grip. Part of the aim of the current chapter is to provide that additional support by examining the account of generation in GC I 1–4.