Page - 215 - in The Priority of Locomotion in Aristotle’s Physics

But one may wonder whether each of the five arguments is actually necessary for Aristotle to reach his goal of showing that locomotion must be the kind of change that is directly caused by the first unmoved mover. Some of these arguments, for instance the first and the fourth, clearly deal with possible objections that may be raised against the priority claim and, thus, certainly fulfil an important function: for, as I pointed out in the beginning, Aristotle needs to be able to provide an appropriate answer to these objections in order for the theory developed in the first six chapters of Phys. VIII, namely the one about the eternity of change and the necessary existence of a first unmoved mover that is source of all change in the cos- mos, to hold. The arguments, which are not to be read as answers to possi- ble objections, for instance the third and the last argument, are nonetheless necessary in order for Aristotle to present a full and consistent theory that as a whole makes it plausible that locomotion alone can be the change which the first unmoved mover imparts. The first three arguments taken as a whole, as we have seen, show that locomotion is ontologically prior in several different respects. This conclu- sion made it clear not only that the other kinds of change ontologically depend on locomotion in various ways—and most importantly that, as the third argument pointed out, all changes can be traced back to the first loco- motion that is caused directly by the first unmoved mover—but also that locomotion per se does not presuppose any of the other kinds of change in any of the three senses discussed in the first three arguments. All this must be shown to be true of the first change that has its direct source in the first unmoved mover; for, if this change depended on or presupposed any other kind of change, it could not possibly be the first change. But by means of these arguments Aristotle at the same time ruled out that any of the other three kinds of change is a possible candidate for the primary kind of change that the first unmoved mover causes directly, for all three, unlike locomo- tion, presuppose the occurrence of another change. Thus, these three argu- ments showed that locomotion as the primary change is the most funda- mental or important, a conclusion which also finds its expression in the fact that, as Aristotle puts it in Phys. IV, change in place is also the “most com- mon sort of change, and that which most properly so called”.3 This is of utmost importance, too, since if one of the four kinds of change is funda- mental to the other kinds of change, then the change that has its origin in the first principle of all change in the cosmos to which Aristotle’s discussion of Phys. VIII leads must be of this kind. But showing that locomotion is necessary for any other type of change to occur, and in this sense is indeed 3 Phys. IV 1, 208a31–32 (Transl. Morison (2002), 11). As I pointed out before, something similar is said in Phys. VIII 9, 266a1–2. For more on the connection between the fact that φορά is the primary and most common kind of change see Morison (2002), 13–15. Conclusion 215 ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen