Physics Book 4 is one of Aristotle's most interesting works, discussing place, time and vacuum. Themistius was a fourth-century AD orator and essayist, not only a philosopher, and he thought that only paraphrases of Aristotle were needed, because there were already such comprehensive commentaries. Nonetheless, his paraphrastic commentaries are full of innovative comment. According to Aristotle, there is no such thing as 3-dimensional space. A thing's exactly-fitting place is a surface, the inner surface of its immediate surroundings. One problem that this created was that the outermost...

Themistius ran his philosophical school in Constantinople in the middle of the fourth century A.D. His paraphrases of Aristotle's writings are unlike the elaborate commentaries produced by Alexander of Aphrodisias, or the later Neoplatonists Simplicius and Philoponus. His aim was to provide a clear and independent restatement of Aristotle's text which would be accessible as an elementary exegesis. But he also discusses important philosophical problems, reports and disagrees with other commentaries including the lost commentary of Porphyry, and offers interpretations of Plato.
Themistius'...