PhD defence
The Metamorphosis of Change: A Study of Plato’s Theory of change
- S. Yue
- Date
- Wednesday 12 March 2025
- Time
- Location
-
Academy Building
Rapenburg 73
2311 GJ Leiden
Supervisor(s)
- Prof.dr. F.A.J. de Haas
- dr. R.M. van den Berg
Summary
This study aims to reconstruct Plato’s theory of change and motion, a topic that has not been adequately or systematically explored despite its critical importance. The pre-Socratic philosophers’ diverse perspectives and debates provide the context for Plato’s development of his theory. In his middle dialogues, Plato introduces his initial model of change and motion, which posits that sensible entities undergo generative change between opposites due to their participation in Forms. At the same time, certain types of motion, such as spatial motion and the motion of the soul, are considered non-generative because they do not involve participation in Forms. The limitations of this first model become apparent in Plato’s later works, particularly in the Theaetetus, Parmenides, and Sophist, where the role of Forms in generative change is shown to be problematic. In response, Plato presents a revised model in his later dialogues. According to this model, sensible entities possess an inherent capacity for movement and change, including oscillation between opposites and irregular spatial motion. Generation occurs when an orderly structure is imposed upon a disordered sensible object by the soul. Consequently, according to Plato’s thought, the world is in a constant state of flux, with all sensible and visible phenomena continuously changing and moving, driven by both inherent and external forces. The souls, along with the gods, introduce order into the sensible world. Thus, the universe is guided by nous or intellectual power.
PhD dissertations
Approximately one week after the defence, PhD dissertations by Leiden PhD students are available digitally through the Leiden Repository, that offers free access to these PhD dissertations. Please note that in some cases a dissertation may be under embargo temporarily and access to its full-text version will only be granted later.
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