This companion to J. O. Urmson's translation in the same series of Simplicius' _Corollaries on Place and Time _contains Simplicius' commentary on the chapters on place and time in Aristotle's _Physics _book 4. It is a rich source for the preceding 800 years' discussion of Aristotle's views. Simplicius records attacks on Aristotle's claim that time requires change, or consciousness. He reports a rebuttal of the Pythagorean theory that history will repeat itself exactly. He evaluates Aristotle's treatment of Zeno's paradox concerning place. Throughout he elucidates the structure and meaning of Aristotle's argument, and all the more clearly for having separated off his own views into the_ Corollaries_.