Amazon.com description: Product Description: This volume presents fourteen essays by leading figures in the fields of ancient philosophy and contemporary metaphysics, discussing Aristotle's theory of the unity and identity of substances, a topic that remains at the center of metaphysical enquiry. The contributors examine the nature of essences, how they differ from other components of substance, and how they are related to these other components. The central questions discussed are: What does Aristotle mean by "potentiality" and "actuality?" How do these concepts explicate matter and form, and how are they related to the actuality of a substance? What is the role of actuality in accounting for the unity and identity of substance? These questions are crucial to an understanding of the unity of composite substances and their identity over time. The aim of the volume is both exegetical and philosophical: to give answers to central problems in Aristotle's metaphysics, and also to stimulate further investigation of the problems defined and the controversies embodied.