Seite - 56 - in The Priority of Locomotion in Aristotle’s Physics

changes in size also has a nature and a size that is specific to it. It is true that a stalactite, for instance, may be said to change with respect to its magni- tude like the aforementioned puddle, but there is no magnitude that is spe- cific to either of them.43 Living beings, by contrast, have a nature that is a source of their respective changes in place, alteration, growth and diminu- tion.44 And, thus, it is primarily with respect to such beings that Aristotle speaks about change in quantity, i.e. growth and diminution. But although Aristotle indeed seems to think of change in quantity pri- marily as a change that occurs in living things, it is nonetheless true that a change with respect to quantity in general encompasses more cases than merely the growth and diminution of living organisms. For, as is stated in Phys. III 1 and V 2 change in quantity basically is change with respect to a certain category possessed by every bodily thing, namely that of quantity.45 Thus, the argument that is supposed to show that locomotion in general is prior to change in magnitude and quality in that it necessarily precedes them needs to show that locomotion is also prior to changes in magnitude undergone by non-living things. The question, however, is whether Aristo- tle really wants to show what he appears to claim in 260a26–29, namely that locomotion is prior to change in magnitude without qualification, or whether he is employing the narrow sense of change in magnitude and rather aims at showing that locomotion is prior to this special kind of change in magnitude, since this for some reason is of special importance to him. I take it that the latter is the case and that Aristotle, as I will now show, has good reasons for proceeding in this way. In what follows I will present what I think these reasons might be. Every living being in virtue of having a nature (φύσις) and a soul (ψυχή) to a certain degree is the principle or source (ἀρχή) of the changes that it undergoes and that are an essential part of its being a living organism. For something that has a nature has within itself the source, or at least a source, of these kinds of life-specific changes.46 Having a soul is what distinguishes living beings from lifeless things, and accordingly in this sense is also described as a principle or source of all the different changes and activities that are specific to living beings.47 The soul in this sense is responsible for 43 This is also the reason why fire, although one may say that it for example grows in a certain sense when I add additional wood, strictly speaking does not do so. Its growth is infi- nite (αὔξησις εἰς ἄπειρον), that is, there simply is no natural end to it. See de An. II 4, 416a15–18. 44 See Phys. II 1, 192b13–15. 45 For the fact that the different kinds of change are derived from the different categories, see Phys. II 1, 220b26–201a9, and V1, 225b5–9 and V2 in general. 46 See Phys. II 1, 192b13–15. 47 This can be seen for instance in de An. II 2 where the soul is explicitly called a source 56 Change in quality and quantity of living beings ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen