Seite - 38 - in The Priority of Locomotion in Aristotle’s Physics

a positive answer to question (1) and asks which kind of change can be eter- nal. Question (3), then, asks which kind of change is the primary one. Understanding why Aristotle is interested in this last question will certainly tell us something about the role played by the arguments that are presented in order to show that the answer to this question can only be locomotion. Yet, as I have already pointed out, this can only be understood by looking at the three questions in conjunction. The answer to the first and the second question is presented in parts of Phys. VIII 7 and 8 by showing that the only change that can be eternal with- out being composed of other changes is a special kind of change in place, namely circular locomotion.87 Thus, it is made clear at the end of Phys. VIII 8 that there can be one single change that is eternal, and furthermore that the change must be this special type of locomotion. According to the theory developed in the previous chapters, this must be the change of which the first unmoved mover is the cause. Yet, Aristotle still seems to think that for some reason it has not been satisfactorily shown that the change which is caused directly by the first mover can only be circular locomotion, although this is the only type of change that can be one and eternal. The reason for this is that the change, which in virtue of having its direct source in the first mover may be called primary, not only needs to be non-composite, one and eternal, but also has to fulfil other criteria. As we will see, one of these criteria is for example that this change must be able to occur independently from the other kinds of change, and as the first existing change cannot presuppose the existence of any other change that causes it, or without which it could not occur. That this is far from self-evident is shown later on by Aristotle when for instance he raises the objection that one might think that in order for something x to undergo locomotion, the subject x of this change in place first of all needs to come to be so that in this sense there could be no occurrence of a change in place without a preceding generation (γένεσις). If this were true, then the first of all changes that according to Phys. VIII 6 is the cause of all other changes certainly could not be locomotion. Yet, since locomotion again is the only possible type of change that can be eternal, one might then come to the conclusion that Aristotle’s theory about there being a first mover that needs to cause one single eternal change in order for change to be eternal must be wrong, since it leads to absurd consequences. Therefore, Aristotle will somehow have to show among other things that, contrary to what one may think, this objection does not threaten his theory. In fact, Aristotle will argue that locomotion, in contrast to each of the other kinds 87 The arguments are presented in 261b28–265a12. 38 The importance of the primary kind of change ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen