Seite - 146 - in The Priority of Locomotion in Aristotle’s Physics

6.2 Locomotion has priority in time, since it is the only change eternals can undergo The passage begins with Aristotle stating what this argument is supposed to show, namely that change in place must also be prior in time to each of the other kinds, that is, it must precede change in quality, quantity, and sub- stance.1 Right after this claim about locomotion’s temporal priority is made, a reason for it (γὰρ) is presented. Locomotion has temporal primacy, Aris- totle tells us, because eternal things cannot undergo any other kind of change apart from locomotion.2 The latter claim is in accordance with other passages in Aristotle, yet, it does not say much more about why this implies locomotion’s temporal priority.3 For something x to be eternal, according to Aristotle, means that it has always existed and always will exist, so that x cannot possibly have come to be at some point and also cannot perish later on.4 For this reason eternal things, apart from being unable to undergo gen- eration and corruption, also cannot and do not undergo any of the two other kinds of change, e.g. in quantity or quality, since both types, in con- trast to locomotion—as it is put in the fifth argument later on—always entail their subject’s “departing its essence” (τῆς οὐσίας ἐξίσταται)5; that is to say, in principle, if they carried on without limit, they would entail their subject’s corruption. Aristotle will argue later on that this is signifi- cantly different with respect to change in place, as this type of change, even if it went on forever would not lead to its subject’s corruption, and in this sense leaves its subject completely untouched. Of the four kinds of change, locomotion, therefore in fact preserves its essence best, which is another reason for its priority, namely its priority in essence.6 The argument also clearly makes use of the assumptions that were shown to be true in the previous chapter: of all the different changes that exist, only change in place can belong to eternal things, since it is the only change capable of being one, continuous and eternal, which, as we have seen, is 1 ἔτι χρόνῳ πρώτην, Phys. VIII 7, 260b29: “Furthermore, it is primary in time.” 2 τοῖς γὰρ ἀϊδίοις μόνον ἐνδέχεται κινεῖσθαι ταύτην. Phys. VIII 7, 260b29–30: “Because for eternal things it is only possible to undergo this change.” 3 See for instance Met. XII 2, 1069b25–26, which suggests that the only change eternals can undergo is change in place, but also Cael. I 3, 270a12–35, where Aristotle shows that the primary body only undergoes circular locomotion and thus is exempt from all other types of change that exist. 4 See for instance Cael. I 12, 281b25–282a1. 5 Phys. VIII 7, 261a20. 6 See Phys. VIII 7, 261a20–23. I shall I explain this in detail in section 7.2. 146 Locomotion has temporal priority ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen