Page - 131 - in The Priority of Locomotion in Aristotle’s Physics

assumption are far from uncontroversial, I will not be able to discuss them here in depth, but only insofar as they are of relevance to my inquiry. Aris- totle proceeds in three steps to show that if there is one continuous and eternal change, this can only be locomotion, or, to be more precise, circular locomotion. First of all he makes clear that none of the other three kinds of change is an appropriate candidate for the change that is one and eternal (261a31–b15), secondly he explains in what way the same is true with respect to most kinds of locomotion (261b28–264b9), and finally he argues that circular locomotion can be one, continuous and eternal (264b9–28). 5.3.1 None of the other three kinds of change can be one and eternal The argument is not merely about showing that there can be locomotion that is one, continuous and eternal, but also about making clear that of the four different kinds of change locomotion is the only type for which this is possible. Therefore, Aristotle first of all explains that it is impossible that any of the other kinds of change could form one continuous and eternal change, and then he shows that this is possible for a certain kind of change in place only. As I will show, the basic argument for the first assumption is that every change that belongs to one of the three other kinds of change, but also every change that is composed of such changes, needs to come to a stop at some point in time, so that it cannot form one single eternal change. I will now show in more detail in what way this assumption is correct. As we know from previous discussions, every change is a change from something (ἐκ τινος) to something (εἰς τι).47 As Aristotle points out else- where, it is because of the fact that every change occurs between limits or extremes that it is unclear in what way one single change that is eternal could exist at all.48 One way in which these changes nevertheless may be eternal, one might think, could be if the subject were to cycle back and forth from the starting point to the endpoint of the change over and over again. In this way, it appears, the subject would be undergoing a change continu- ously, that is, there would be one continuous eternal change of one single subject. As I pointed out before, this seems to be reasonable, since the sub- ject in these cases would undergo a succession of changes so to speak that are all of the same genus, which makes it possible for their extremes to become one and the same, thus enabling them to form one continuous whole with respect to that in which they occur. Accordingly, if we think of 47 See for instance Phys. V 1, 224b1, VI 10, 241a27, and VIII 2, 252b10. 48 See Phys. VI 10, 241a26–28, and VIII 2, 252b9–12. As I stated before, it is part of the task of Phys. VIII 8–9 to show that there nonetheless is one continuous and eternal change (see section 2.4.3). Locomotion alone can be one and eternal 131 ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen