抄録
In the first Part of the 7heaetetus (151 d 7-187 a 8), Theaetetus tries to define knowledge as perception. In this paper, I would like to clarify how Plato explains the interrelation between this definition and other two theses, 'Man is the measure of all things' and `All things really are in process of becoming as the result of movement and change'. I will explain how the definition and other theses are different, but based on another Anti-Parmenidean thesis that nothing is one thing just by itself. Therefore the definition and other theses are related to the Anti-Parmenidean thesis, which Plato wants to elaborate in the Theaetetus 151 d 7-153 a 4.
