This volume contains works on Aristotle's Physics by Philoponus and Simplicius, rival Neoplatonists of the sixth century AD, the former a Christian, the latter a pagan.

Paul Lettinck has restored a lost text of Philoponus by translating it for the first time from Arabic (only limited fragments have survived in the original Greek). The text, recovered from annotations in an Arabic translation of Aristotle, is an abridging paraphrase of Philoponus' commentary on Physics Books 5-7, with two final comments on Book 8. The Simplicius text, which consists of his comments on Aristotle's treatment of the void in chapters 6-9 of Book 4 of the Physics, comes from Simplicius' huge commentary on Book 4. Simplicius' comments on Aristotle's treatment of place and time have been translated by J. O. Urmson in two earlier volumes of this series.