On Aristotle's Physics 4

"In his Physics 4, Aristotle defines place and time and denies the possibility of vacuum. Themistius, whose commentary is translated in this volume, wrote in the fourth century A.D. The fact that his commentaries are called paraphrases should not be allowed to conceal their importance. Some of his ideas are very original and he was taken seriously by later commentators and used as an authority by Aquinas." "Aristotle denies three-dimensional space and substitutes the idea of a thing's place as its immediate surroundings. Themistius supports Aristotle's denial. However, he reveals that the philosopher-doctor Galen, in the late second century A.D., had argued for the reality of space by imagining a bronze jar whose contents shrink, without any other matter coming in to fill the gap. Themistius complains that this thought experiment begs the question by assuming the very spatial extension, or gap, that Galen wants to prove." "Aristotle's conception of place as surroundings makes it problematic how his outermost sphere, which carries the stars, can have any place, given that it has no surroundings. Themistius suggests various solutions, including treating the inner spheres as surroundings." "Turning to time, Themistius again reveals Galen's objections to Aristotle and defends Aristotle from the charge of giving a circular definition of time. On the other hand, Themistius criticizes Aristotle for saying that there would be no time if there were no soul. Most of these points were debated by later commentators."--BOOK JACKET.