After these things, [one must observe] that neither matter nor form comes to be, I mean the ultimate ones. For everything undergoes change as something and by something and into something. The by something is the initiating mover, the something is the matter, and the into which is the form. Therefore they continue into an infinite regress, if not only bronze comes to be round but also the round comes to be and the bronze comes to be. Indeed, there must be a stopping point. (My translation, Metaphysics 1069b35-1070a4) (1) (2).
There are at least two errors in the explanation of change, considered as opposite extremes. One is to claim that something comes from nothing. This is no explanation, however, for we simply have two incidentally contiguous events, the state of non-being and then the state of being, which are erroneously construed as having a causal connection. The other error is to become “cause happy” and multiply explanations, destroying any causal cogency which an account of change might have had otherwise. It is this second notion which I think Aristotle is trying to neutralize. When he claims that having to give an explanation for both the “round” and the “bronze” apart from the bronze becoming a round, leads to an “infinite regress,” the point he is pressing is that, unless we accept the termini of a change “from a this, to a that” we are stuck with the philosophically inert task of endless explanation. In this erroneous method, from Aristotle’s point of view, what is being proposed is simply an ever increasing succession of events, with nothing tying it together. A subject of change would provide this unity of account. Without this subject of change, a substratum, there is a chain of succession both receding and similarly reaching out into the future without limit. There is likewise nothing that could be imposed on this succession to prevent it from applying to the cosmos as a whole. Thus the “infinite regress” is perhaps better understood as an infinite succession, intended primarily to single out for criticism a futile explanatory chain. The explanatory role of change cannot be pawned off, the buck must stop somewhere.
Μετὰ ταῦτα ὅτι οὐ γίγνεται οὔτε ἡ ὕλη οὔτε τὸ εἶδος, (35)
λέγω δὲ τὰ ἔσχατα. πᾶν γὰρ μεταβάλλει τὶ καὶ ὑπό
(1070a) τινος καὶ εἴς τι· ὑφ’ οὗ μέν, τοῦ πρώτου κινοῦντος· ὃ δέ, ἡ
ὕλη· εἰς ὃ δέ, τὸ εἶδος. εἰς ἄπειρον οὖν εἶσιν, εἰ μὴ μόνον
ὁ χαλκὸς γίγνεται στρογγύλος ἀλλὰ καὶ τὸ στρογγύλον
ἢ ὁ χαλκός· ἀνάγκη δὴ στῆναι.
Note that I have flip flopped (again!) on the translation of the last sentence, owing to considerations laid out above.