If one were to seek a definitive answer to the contrast between the sophist and the philosopher, one might naturally turn to Plato's Sophist. The dialogue enumerates a number of collections and divisions, ending with a specific definition of the sophist. The dialogue's final definition of the sophist has the Stranger declaring that they have reached the truth about his nature:

However, despite the Stranger's own sense of clarity about his definition of the sophist, Plato's own voice in the dialogue is more difficult to discern. Unlike most Platonic dialogues, in which Socrates is a major speaker, here Socrates sits silently at the feet of the Eleatic Stranger as he performs diaresis and explores metaphysics. The identity of this stranger is mysterious. While other dialogues such as the Theaetetus often give us detailed accounts of their character's personalities or biographies, the Stranger is never full explained. We know little about him, other than that he is from Elea.