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....