• ancient metaphysics
• ancient physics
• Aristotle
• change
• destruction
• generation
• motion
• opposites
• per accidens
• per aliud
• per se
• philosophical commentary
• Physics
• termini

The fifth book of Aristotle’s Physics has been relatively neglected by current scholarship and, unlike every other book of the same work, no complete philosophical commentary on it is currently available in a modern language. The present thesis aims to be a first step towards a more thorough consideration of this ancient text and the doctrines contained in it, with a particular focus on Aristotle’s theory of change. This is primarily achieved through an in-depth commentary on the first chapter, where Aristotle presents key metaphysical and structural claims about change (μεταβολή) and argues for a distinction between change and motion (κίνησις).
In the commentary, Aristotle’s claims are analysed both as they are presented in the text and in the light of other relevant parts of the corpus, especially Physics 1–3 and De generatione et corruptione 1. Such an approach proves particularly fruitful as the chapter turns out to introduce several ideas central to Aristotle’s conception of change, but seldom elaborates on the deeper reasons underlying them, which can however be reconstructed by taking a wider perspective. Finally, a considerable part of the thesis is devoted to the case of generation and destruction (γένεσις καὶ φθορά) and Aristotle’s argument to the effect that they are not motions (κινήσεις): I argue that Aristotle sets these changes apart from motions not merely for the sake of classification, but as a development of his own conceptions of motion on the one side and generation on the other.