Cropsey, Joseph, "Sophist," Plato's World: Man's Place in the Cosmos, Chicago: University of Chicago Press, 1995, 69-110.
Excerpt:
The transition to the Sophist is made complex by the complexity of what precedes it, for this dialogue is preceded in one way by Theaetetus and in another by Euthyphro. As preceded by Theaetetus, the transition is from the atmosphere of Protagoras, conveyed through the medium of Theodorus and Theaetetus, to the atmosphere of Parmenides, conveyed in the energy of the Eleatic Stranger, with movement toward the definition of the philosopher.
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