Page - 181 - in The Priority of Locomotion in Aristotle’s Physics

or sensory capacity, ontologically depends on a preceding locomotion.43 At this point I can only say that it will become clear later on that the ontologi- cal posteriority of the soul’s capacity for locomotion, as well as the fact that it is posterior in coming to be, does not contradict its essential priority, but even needs to be understood as the expression of its priority in essence. The relation of ontological dependency that exists between certain capa- cities finds its expression in the process of development of any living thing, even though Aristotle does not point this out explicitly. If (1) the capacity to move oneself cannot exist without the capacity for sensory activity, and if, as Aristotle presupposes, (2) capacities to perform certain things are developed at different stages and times in the process of coming to be, then it follows that (3) a capacity x that has ontological priority over a capacity y also will be prior in the process of coming to be. Accordingly, the nutritive capacity, for instance, will always be prior to the capacity to locomote in the coming to be of every living thing. In this way the order of ontological priority of the soul’s capacities corresponds to the order of their develop- ment and hence their priority in the process of coming to be. Since the rela- tion of being prior in coming to be is the converse of the relation of being prior in being, it follows that the higher the ontological priority of a soul’s capacity, the lower its priority in essence. The relation between the three kinds of priority may be made clearer by means of the following diagram: A B A B → → locomation of x’s father coming to be of x t1 t2 t3 t eternal locomation of the sun priority in essence priority in coming to be k ontological priority of capacities 1 2 3 4 Fig.3 In Fig.3 something x is in the process of becoming a full member of kind k. The vertical lines represent different moments in x’s existence. At t4 x is 43 It is important to emphasize, therefore, that the fact of the locomotive capacity’s onto- logical posteriority is absolutely compatible with what is stated in all three arguments for locomotion’s ontological priority, although one might think differently at first. I have just explained in what way this is true with respect to the third argument. Also according to the first argument a change that has its source in a living thing’s nutritive or sensory capacity, i.e. in a capacity that is ontological prior to the locomotive capacity, nonetheless is ontologically dependent on the locomotion that necessarily has to occur in order for the alteration or growth to take place (see chapter 3). As the second argument shows, it is true in the same way that any such change in quality or quantity will be accompanied by a change in place, while the converse does not hold (see chapter 4). Locomotion is prior in essence, since it is last in coming to be 181 ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen