Page - 184 - in The Priority of Locomotion in Aristotle’s Physics

The understanding of priority in essence presented above is of utmost importance to the later discussion of the second argument for locomotion’s priority in essence. Without it, as I will show later, the first and second argument for locomotion’s essential priority cannot argue for the same kind of priority, but for two different kinds of priority. Thus, only with the addi- tional criterion of specificity at hand does it become clear that Aristotle has not made the mistake of equivocation. After these remarks I will now sum- marize the results of the discussion of the first argument for locomotion’s priority in essence. 7.1.6 Conclusion As we have seen, Aristotle is right to presuppose the truth of the first pre- mise, i.e. of the claim about reversed priority, on which his argument for locomotion’s priority in essence is based. The concept of priority in essence that underlies this claim is that for x to be prior in this way it must fulfil its essence and form to a higher degree than the thing to which it is compared. I have also showed that the term ‘locomotion’ is used in a special way in this argument. Accordingly, saying that locomotion is prior to the other kinds of change in our context means that the capacity to locomote is prior to the capacities of a living thing’s soul to be a source of the other two kinds of non-substantial change, and also that this is more specific to being that which something is according to its form and nature. My discussion has also showed the truth of the second premise on which this argument for locomotion’s priority in essence is based, namely that it is last in the coming to be of living things insofar as its capacity comes to things later than the capacity for the other two kinds of change. If one takes into account that ‘locomotion’ stands for ‘capacity to cause one’s own locomotion’, then the reconstruction of the argument presented is as follows: (1) If x is posterior to y in the coming to be of living things, then x is prior in essence to y with respect to living things. (2) In the coming to be of living things the capacity to cause locomotion is posterior to the capacity to cause alteration, growth and diminu- tion. (3) Therefore, in living things, the capacity to cause locomotion is prior in essence to the capacity to cause alteration, growth and diminu- tion. 184 Locomotion is prior in essence ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen