Page - 161 - in The Priority of Locomotion in Aristotle’s Physics

theory about the existence of change in the cosmos. The movements of the sun that occur after a certain change has taken place of course do not play any role in this change and thus are irrelevant for the question whether there is a locomotion that in general precedes any generation without itself being preceded by some other change. Aristotle therefore successfully shows that locomotion is not posterior in an unqualified sense, but only with respect to the generation of perishable things in the sublunary sphere. As we have seen, this fits very well with the assumption that locomotion has general priority, since for each generation there is something which undergoes locomotion prior to it, namely the sun. Accordingly, it also can- not be the case that, contrary to what the objection seems to suggest at first glance, generation is prior to the other three kinds of change.49 This, however, establishes locomotion’s temporal priority not only over generation, but also over the other kinds of change with respect to which locomotion is the last to occur in individual perishable things. For, as is pointed out at the end of the passage, if not even generation is prior to loco- motion in the way just stated, how could this be the case for the other kinds, which depend on the respective thing’s coming to be and therefore can only occur after it? For alteration, growth, and diminution, as well as corruption, all presuppose an existing substance with respect to which the change may occur and in this sense are changes that succeed (ἐφεξῆς) and thus are pos- terior to generation. But if generation is posterior to locomotion, then a for- tiori all succeeding changes are also posterior to it.50 With respect to these changes it is correct that the respective subject needs to come to be first of all before any of them can occur, but as we have seen in this chapter the case is significantly different for locomotion, as there are eternal things which change in place and since these changes are responsible for any gen- eration that occurs. Thus, one may conclude that Aristotle in the passage discussed in this chapter successfully shows that locomotion has priority in time over each of the other kinds of change.51 In doing so he once again presented reasons for the claim that locomotion is the primary kind he 49 Aristotle also presents yet another argument for this claim in a parenthetical remark in 261a8 which, however, is not necessary for the whole argument to work. According to this argument it is impossible that generation could be the primary kind of change that is directly caused by the first unmoved mover and which is the cause of all other kinds of change in the cosmos, “because then everything that is changing would be perishable”, i.e. eternal things as well, which for Aristotle is impossible. 50 See Phys. VIII 7, 261a7–12. 51 Therefore, I cannot agree with Graham (1999), 127–128, that Aristotle does not show that locomotion is prior in time but “just prior in some general sense”. Graham however is right in saying that in this argument not every step is spelled out in detail. But as I have shown in my discussion of the passage it nonetheless becomes quite clear in what way Aristo- tle shows that locomotion is primary in time in general. The locomotion of the sun as a cause of generation 161 ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen