This post concerns not a matter of philosophy, nor even the interpretation of texts, but rather 'redaction criticism', that is, speculation about the order of composition of parts of texts and how these parts were combined together into the whole text that we have today.
My interest is an argument, in the redaction criticism of Aristotle's Metaphysics, which I find in a piece by Daniel Devereux, "The Relations between Books Zeta and Eta of Aristotle's Metaphysics" (OSAP Winter, 2003). The argument is as follows.
In Z 8, Aristotle argues that form, although it begins to exist and ceases to exist, properly speaking neither is generated nor suffers corruption, because the only things that can be generated (or made), and thus which can suffer corruption (or be destroyed), are composites of form-in-matter.
Scholars have argued...that chapters 7-9 and chapter 12 are 'later insertions' in Z since (i) they are intrusive in their context and (ii) there is no mention of them in the summary at the beginning of H. Further, in H 3 Aristotle says that it was shown elsewhere--not in Z or H--that forms are neither generated nor produced (1043b16-18). But Z 8 contains an argument for this thesis, so it seems that this chapter was not a part of Z when the reference in H 3 was written. These details suggest that there was an early, 'first' version of Z which is summarized at the beginning of H, and a later expanded version containing the 'inserted' chapters, Z 7-9 and Z 12.This is an interesting argument. Yet it seems to me weak, and perhaps even without any force. My concern isn't with the disputable assumption that the summarizing paragraph at the beginning of H was meant to be so thorough that, if something is not mentioned in that paragraph, then we may deduce that that was not contained in the version of Z which the paragraph attempts to summarize.
Other parts of Z were apparently revised at the time that Z 7-9 were added. In Z 15, for example, Aristotle mentions that it was shown earlier that the form of a composite is neither generated nor produced (1039b26-27). This is clearly a reference to the argument in Z 8, which has now been incorporated into Z. But H was apparently not revised at this time: the summary in H 1 was not expanded to take account of the additional chapters in Z, and the reference in H 3 (1043b16-18) was not changed to 'it was shown earlier' [rather than elsewhere] that forms are neither generated nor produced' . The expanded and revised version of Z which we possess is later than H -- H is contemporary with an earlier, shorter version of Z.
It's rather with the nature of the two apparent back references. I'll paste them here and later share with you my doubts.
The reference in Z 15, 1039b26-27
e)pei\ d' h( ou)si/a e(te/ra, to/ te su/nolon kai\ o( lo/goj (le/gw d' o(/ti h( me\n ou(/twj e)sti\n ou)si/a, su\n th=| u(/lh| suneilhmme/noj o( lo/goj, h( d' o( lo/goj o(/lwj), o(/sai me\n ou)=n ou(/tw le/gontai, tou/twn me\n e)/sti fqora/ (kai\ ga\r ge/nesij), tou= de\ lo/gou ou)k e)/stin ou(/twj w(/ste fqei/resqai (ou)de\ ga\r ge/nesij, ou) ga\r gi/gnetai to\ oi)ki/a| ei)=nai a)lla\ to\ th=|de th=| oi)ki/a|), a)ll' a)/neu gene/sewj kai\ fqora=j ei)si\ kai\ ou)k ei)si/n: de/deiktai ga\r o(/ti ou)dei\j tau=ta genna=| ou)de\ poiei=.
The reference in H 3, 1043b16-18
(a)na/gkh dh\ tau/thn h)\ a)i/+dion ei)=nai h)\ fqarth\n a)/neu tou= fqei/resqai kai\ gegone/nai a)/neu tou= gi/gnesqai. de/deiktai de\ kai\ dedh/lwtai e)n a)/lloij o(/ti to\ ei)=doj ou)qei\j poiei= ou)de\ genna=|, a)lla\ poiei=tai to/de, gi/gnetai de\ to\ e)k tou/twn.Now the substance must be either eternal or perishable without ever being in process of perishing, and generated without ever being in process of generation. It has been clearly demonstrated elsewhere that no one generates or creates the form; it is the individual thing that is created, and the compound that is generated.