Page - 192 - in The Priority of Locomotion in Aristotle’s Physics

substance, i.e. essence itself.58 Because of this it is puzzling that here, never- theless, x in undergoing locomotion is supposed to change in essence less than when undergoing any of the remaining non-substantial kinds. This problem might make one think that in our passage Aristotle by ‘x departing from its essence’ does not mean ‘x undergoing a change in essence’ and that οὐσία therefore does not stand for ‘essence’ or ‘substance’, but is employed in a different sense here. Indeed, it was suggested by Wagner that οὐσία has a broader meaning here and cannot be reduced to ‘essence’ in this con- text: whenever x undergoes any change it “departs from its οὐσία” (τῆς οὐσίας ἐξίσταται) in some way, but without the essence of x being neces- sarily affected.59 According to Wagner, Aristotle is saying exactly the same thing when he says that ‘x departs from its essence’ (ἐξίσταται τῆς οὐσίας) and that ‘something of x’s being changes’ (μεταβάλλει τοῦ εἶναι), the expression used in the justification presented for sentence (1). This seems attractive since it would solve all the problems that I have pointed out. For reasons I will state later, I nevertheless take it that Aristotle intends to make a distinction between the two cases and that this distinction is cru- cial for the argument made here. On my understanding, a change in being (τοῦ εἶναι), as we have seen, would be a change of the intrinsic attributes of x. It may concern accidental, but also essential attributes—a case I have not discussed so far. Thus, a change in being may, but does not have to, affect its subject’s essence. A change in essence, by contrast, always does so. It is more than the mere change of some, perhaps accidental attributes of the change’s subject and changes the very substance that underlies this change at its beginning; the subject of generation or corruption does not outlast such a change, and no longer exists when the change is over. Accordingly, a change in essence is also a change in being, but not vice versa. But if, as suggested by Wagner, οὐσία does not stand for ‘essence’ here, and is used in a broader sense, this would raise the following difficulty: Aristotle claims that locomotion has priority in essence and presents two arguments for this claim. As my examination of the first argument has shown, this argument clearly presupposes the concept of essence: of two things x and y, both being of one and the same kind k, x is prior to y, if and only if x fulfils the essence of k to a higher degree than y. A consequence that results from Wagner’s reading of the second argument is that the con- 58 For instance, the distinction between κίνησις and μεταβολή introduced in Physics V is based on this essential difference. 59 See Wagner (1967), 690. Also Hardie & Gaye seem to take τῆς οὐσίας and τοῦ εἰναῖ to refer to the same, and hence take them to stand for ‘its being’, and ‘of being’ respectively, although it is unclear what ‘being’ stands for in this context. 192 Locomotion is prior in essence ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen