A collection of essays by leading scholars of Aristotle which illuminate key ideas at the heart of his philosophy.

Introduction; 1. Teleology, Platonic and Aristotelian David Sedley; 2. Biology and metaphysics in Aristotle Robert Bolton; 3. The unity and purpose of On the Parts of Animals I James G. Lennox; 4. An Aristotelian puzzle about definition: Metaphysics Z.12 Alan Code; 5. Unity of definition in Metaphysics H.6 and Z.12 Mary Louise Gill; 6. Definition in Aristotle's Posterior Analytics Pierre Pellegrin; 7. Male and female in Aristotle's Generation of Animals Aryeh Kosman; 8. Metaphysics ¿. 7 and 8: some issues concerning actuality and potentiality David Charles; 9. Where is the activity? Sarah Broadie; 10. Political community and the highest good John M. Cooper; Publications of Allan Gotthelf.