Seite - 43 - in The Priority of Locomotion in Aristotle’s Physics

out x, while x can be without y, so that the relation between x and y in this sense may be described as an asymmetric relation of ontological depen- dency. At first glance the passage seems to suggest that Aristotle is present- ing an argument for locomotion’s general ontological priority over the other two kinds of non-substantial change. But I will show that in fact when one looks at it more closely, it becomes clear that Aristotle is only arguing here for the claim that locomotion has this kind of priority with respect to spe- cial cases of these changes, namely change in quantity and quality as they occur in living beings. According to my reading the argument therefore shows that any growth, diminution, and alteration that occurs in a living organism necessarily needs to involve some preceding locomotion, while the converse does not hold. It is important for Aristotle to make clear that this is the case, since based on what is stated in certain passages of Phys. VIII one might think that the processes that animals as self-sustaining organisms seem to undergo at cer- tain times or even persistently—growth for instance—precede locomotion or even might be necessary for locomotion to occur in general. This, how- ever, clearly would contradict the claim that locomotion in general has priority over the other kinds of change. Therefore, Aristotle is showing in this first argument that any change in quantity as well as any alteration that occurs in a living being presupposes a preceding locomotion, not necessa- rily of that which changes in quantity or quality, but in general of some- thing that may or may not be identical with the subject of these other two changes. But by showing that in this sense change in place is necessary for the other types of change to occur, I will argue, it is established that change in place has ontological priority over the other two kinds of non-substantial change with respect to changes in living beings, but also with respect to any other changes of which animals as self-movers may be a cause. As I will show, this amounts to saying that any occurrence of the other kinds of change that is caused by a sublunary source of change always implies a pre- ceding locomotion, while the occurrence of a locomotion does not necessa- rily entail any of the other two kinds of change. The basic structure of the argument presented by Aristotle for the prior- ity of locomotion over change in quantity and quality is this: (1) The occurrence of growth as well as diminution for which living beings are responsible presupposes a preceding alteration. (2) The occurrence of alteration presupposes a preceding locomotion. (3) Hence, growth, diminution, and alteration for which a living being is responsible presuppose a preceding locomotion. In order to fully understand whether and, if so, in what way the argument makes clear what Aristotle aims to show, a more detailed analysis of the Overview 43 ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen