Page - 125 - in The Priority of Locomotion in Aristotle’s Physics

fulfilled: the two changes are one in genus and in species, both are altera- tions that lead from the same starting point, that is a certain disease of the eyes, to the same endpoint, the health of the eyes, and both changes occur at one and the same time. But since both processes take place in two differ- ent men and therefore in two different subjects, condition (1), the unity of the subject, is not fulfilled. This also makes clear why the domino example does not present the case of a change which is one without qualification: also in the two domino examples condition (1) clearly is not fulfilled, since each domino is the subject of a single change. Therefore, it is clear why this kind of change cannot be one, for what should one say is undergoing this change? There is no continuous whole which may serve as the subject of this change, a change that is composed of a number of succeeding changes. This chapter also explains why changes that fulfil conditions (1) and (3), but not condition (2) cannot be one without qualification and continuous as a whole, and for this reason a fortiori cannot be eternal. Consider the fol- lowing of Aristotle’s examples. Suppose a man immediately after having changed his place by running a mile falls into a fever, i.e. is subject to an alteration.30 One might think that the subject is one since in both changes the man undergoes a change. The time is one as well, as the latter change immediately follows the former. Why should one not say that this is one continuous change? The reason Aristotle presents is this. Any change that is a change in the strict sense is continuous. As we know from the explanation of ‘continu- ous’, something is continuous if the limit at which its parts touch are one and the same.31 Accordingly, the limit at which adjacent parts of one con- tinuous change touch must be one and the same. The same is true for two changes, if we are to think of them as parts of a continuous change that may be formed by them: the extremes (ἔσχατα), i.e. the limits32, at which the two changes touch need to be one and the same. But this is the reason why two changes that differ in genus can never form one continuous change. Think of Aristotle’s example again: although it is possible that a man, immediately after having run a mile, falls into a fever, it is impossible that the extremes of the change in place and the change in quality become one. The extremes of the two changes differ in category, one being the end of the run that is connected to a certain place, the other the starting point of falling into a fever, a certain quality. The same, of course, is true of any two changes which differ with respect to the genus in which they occur. A succession of changes that differ in genus, therefore, can never form one 30 For this example see Phys. V 4, 228a27–28. 31 See p.119, n.11 and n.12. 32 As Phys. V 4, 228a29–30, in combination with the explanation of συνεχές in V 3, show, Aristotle thinks of the extremes (ἔσχατα) of changes as their limits (πέρας). The unity of the eternal change 125 ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen