Motion and Reality

Abstract

The paper deals with Zeno's celebrated arguments against the reality of motion. My aim is, however, not to offer a new solution for them, but to bring forward for consideration the general claim assumed in them about the criterion of 'reality' : i.e. the claim that what is logically (λóγφ) impossible must not be regarded as 'real'.
With this intention I first reexamined Aristotle's two different treatments (the one, in Physica Z2, 9, the other, ibid. θ8) of the 'dichotomy' and the 'Achilles and the Tortoise' in some detail, and tried to make clear in what points they were inadequate for Zeno's contention.
Then, in conformity to the results of these considerations, the solutions offered by modern philosophers, such as H. Bergson, B. Russell, C. D. Broad and G. Ryle (together with W. James, A. N. Whitehead and J. N. Findlay), were reviewed and classified.
It was observed that the points made by some of these writers (C. D. Broad and G. Ryle) are, in principle, exactly the same as those in Aristotle's first solution (Phys. Z2), which Aristotle himself regarded as insufficient. And as to the others, in spite of their elaborate efforts, it must be admitted that Zono's problem about motion, as such, has not yet been finally answered and, moreover, can never be answered. The reason of this impossibility to be answered is simply that, under the rule to be observed in the treatment of this problem, the reality (i.e. rationality or logical possibility) of motion should be shown without defining in advance 'what is perceived' (τò αiσθητóυ, to which motion belongs) as 'real', and that 'what is perceived' can never be perfectly rational i.e. 'to be grasped by λóγοζ.