Argument and Dialectical Structure in Physics VIII 1
Keywords:Aristotle, Physics, Dialectic, Demonstration, Principles
Physics VIII 1 presents a multi-stage argument concluding that there was not, nor ever will be, a time when there was not nor will not be motion (Phys. VIII 1.252b5-6). In this paper I shall argue that chapter’s argument is dialectical in a precise way. My claim will be that Physics VIII 1 is apodeictically conditioned – its structure must be understood in terms of the theory of science in the Posterior Analytics and the methods for establishing principles in the Topics. Physics VIII 1 is not demonstrative in a straightforward deductive way, but is structured with the nature of a scientific genos and requirements for scientific knowledge always in mind. Aristotle begins by asking about the eternality of motion, posing a pair of conceptual opposites that form a mutually exclusive and logically exhaustive dichotomy. But the initial statement of the dichotomy turns out to require substantial unpacking, leading eventually to a single remaining option, that motion in the cosmos is eternal. But the status of this conclusion itself turns out to be problematic. Put in terms of Aristotle’s theory of science, all phusiologoi made motion a posit or hypothesis, whether they regarded motion as eternal or not. Though Aristotle has rejected one option, at a deeper level, he finds all previous accounts lacking. Because motion is fundamental to all coming-to-be-and-passing-away, what is at stake is the status and adequacy of a principle governing the whole science of nature (tên theôrian pasan; 250b17). In this way, the chapter prepares for the subsequent investigation into the principles of cosmic motion.