Aristotle on the Impossibility of Anaximander's apeiron: On Generation and Corruption, 332a20-25

In On Generation and Corruption, Aristotle rejects the very possibility of such a thing as Anaximander's apeiron. Characterized as a kind of intermediate stuff, the apeiron turns out to consist of contraries and as such is impossible. Commentators have rightly noted this point and some have also indicated that Aristotle offers an argument of sorts for his negative estimate. However, the argument has received scant attention, and it is fair to say that it remains unclear exactly why Aristotle rejects Anaximander's intermediate stuff. Indeed, it is unclear how Aristotle's argument is supposed to run in the first place. This paper offers a reconstruction of Aristotle's argument for the impossibility of the apeiron, and on this basis offers to explain Aristotle's grounds for rejecting Anaximander's intermediate stuff. This is especially called for in light of the fact that Aristotle himself thinks that there can be intermediate stuffs. Finally, some attention is given to the parallel between the apeiron and Aristotle's prime matter.