Page - 80 - in The Priority of Locomotion in Aristotle’s Physics

For Aristotle the crucial difference seems to be that the parts of the sphere always change “in a place of equal size” (ἐν τῷ ἴσῳ τόπῳ) while the parts of what undergoes growth or diminution change to a larger or a smal- ler place, as by growing or diminishing they become larger or smaller.22 But in what way is this a reason for saying that the parts of the sphere form a whole with respect to their change in place, while the parts of the growing infant do not do so? In fact, one might argue that this confrontation of the two cases shows that growth and diminution are changes in place to a higher degree than the revolving sphere, for the place which the subject of the former occupies changes, while one might argue that the sphere’s place does not change at all—indeed objections of this kind were uttered against Aristotle’s claim that the revolving sphere undergoes a locomotion in the full sense.23 But let us return to our question. In what way is our argument supported by the fact that each part of the revolving sphere always changes to a place of equal size, while each part of that which changes in size changes to a smaller or greater place? It seems to me that an answer to this question will lead us to a criterion for distinguishing between a change in place as a whole and one with respect to its parts. Yet, in what way might this differ- ence be responsible for saying that something x undergoes one and not the other of the two ways of changing in place? Contrary to what interpreters of this passage say, I would argue that the function of contrasting the two cases is to show that the inner spatial order between the parts of the sphere, and of what undergoes locomotion as a whole, does not change in any way, while the relation between the parts of that which grows necessarily changes, if the space that is occupied by the parts, and hence the whole, expands.24 Even if the proportions of that which is growing remain exactly the same throughout the whole change, the spa- tial relation of its parts changes. The distance between the infant’s hands for instance increases when the infant grows as a whole, so that the spatial rela- tion or order between the two hands changes. In growing, the parts of the body come to occupy another location in the whole to which they belong in 22 τὰ μὲν γὰρ ἐν τῷ ἴσῳ τόπῳ μεταβάλλει τοῦ ὅλου μένοντος, τὰ δὲ τοῦ αὐξανο- μένου ἀεὶ ἐπὶ πλείω τόπον, ἐπ᾽ ἐλάττω δὲ τὰ τοῦ φθίνοντος, GC I 5, 320a22–25. 23 See Phys. VI 9. 24 Averroes and Joachim take this comparison to show that the change in place the grow- ing thing undergoes is different from circular locomotion. According to their reading Aristo- tle operates in two steps: (1) he argues that the change in place of that which grows is different from rectilinear locomotion, then (2) that it also differs from circular locomotion (see Aver- roes, Middle Commentary, p.28), Joachim (1922), 112). Yet, this reading does not explain why for instance the problematic case I have presented does not count as a change in place as a whole, while, as I will show, my reading does. 80 Locomotion necessarily accompanies each of the other kinds of change ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen