Page - 78 - in The Priority of Locomotion in Aristotle’s Physics

with respect to its parts, since in contradistinction to something that under- goes a locomotion it does not change in place as a whole. The growing thing’s parts are changing in place19 and thus need to be taken as the true subject of the locomotion that occurs while the whole is growing. The sub- ject of the growth in this sense is different from the subject of the locomo- tion that occurs at the same time. The actual subject of this locomotion is a part of the subject of the change in quantity. If this is correct, then there basically seems to be a way in which Aristotle may rightly claim that whatever is increasing or decreasing in size in a cer- tain sense is also undergoing a change in place. But, as I will now show, there is a problem with this solution. The problem is that there are cases of growth or diminution in which the subject seems to undergo change in place as a whole in virtue of its change in size. But this would clearly contra- dict Aristotle’s claim that although a change in the size of a subject goes hand in hand with a change in place, this is only true in the sense that it does so with respect to its parts. In dealing with this problem we will get to know an important feature of locomotion, namely that the parts of what undergoes this kind of change strictly speaking do not need to change their spatial order in any way whatsoever. Or, to put it another way, it does not follow from the fact that something x undergoes a locomotion that x’s parts change, since change in place per se does not entail any other change. 4.2.3 Change in place implies no change in the spatial order of the subject’s parts As we have seen, Aristotle thinks that what grows changes in place only with respect to its parts. However, it is also true that what changes in place as a whole does so with respect to all of its parts. Now, if something changes in quantity as a whole, then according to GC I 5 all of its parts also change in quantity.20 Suppose, for instance, an infant is growing as a whole. The change in place of that which grows, in this case of the infant, is the change in place of its parts. The change in place of the parts again occurs in virtue of their change in quantity. Now if the infant is growing as a whole, and therefore all parts of its body are growing, then it seems that all of these parts also need to change in place in virtue of their growing. Since the changes in place of the parts derive from the growth of the same, one might think that the change in place of all the parts comprises a change in place of the infant 19 τὰ μόρια μεταβάλλει κατὰ τόπον, CG I 5, 320a21–22. 20 This is one of the criteria that according to GC I 5 need to be fulfilled for it to be said that growth or diminution has occurred. See GC I 5, 321a18–21. 78 Locomotion necessarily accompanies each of the other kinds of change ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen