The Sophist and the Statesman seem to present themselves as a kind of philosophical trial of Socrates (see Cropsey 1995; Friedländer 1964, chapters III.26 and 27; Howland 1998; Miller Jr. 1980; Voegelin 1987/1956, chapter III.4). Plato placed both dialogues in continuity with the Theaetetus, which ends (210d2-4) when Socrates must go to the King-Archon in order to answer Meletus' indictment, and, though they do not overtly remind us of this fact, they do explicitly refer to the agreement to meet again with which Socrates concluded the conversation, and allude to the issues of the trial (cf. Statesman 299b2ff). We thus seem to be justified in suspecting that the dialogues represent a certain evaluation, if not necessarily an indictment, of Socrates' philosophic practice, though the verdict, if any, is not quite evident.
This point has been denied, even by people who take seriously the dramatic character of the dialogues. Blondell (2002, pp. 386-389), for example, argues that Plato doesn’t sufficiently indicate dramatically the connection to the trial to make it the central issue, an argument all the more curious given that her general views -she claims that the introduction of the Eleatic Stranger is Plato’s way of “silencing” Socrates- actually lend themselves to a trial-focused interpretation. Lane (1998, p. 154 note 37) instead suggests that the allusion to Socrates’ trial at Statesman 299b2-e10 is flawed, though she does not suggest that it is not an allusion to Socrates. Regardless of the merits of these arguments, the allusion to Socrates' trial invites the reader to think of the Eleatic Stranger as Socrates' potential judge, a rival in the practice of philosophy in comparison with whom Socrates may (or may not) be found wanting.
There are at least two ways in which the allusions to the trial of Socrates could matter, however. We could consider the Stranger to be fundamentally friendly to Socrates, a judge who will exonerate him where the Athenian people did not; or we could consider him a rival to Socrates, someone who will (wholly or in part) convict him for being a bad citizen, a bad philosopher, or both, and thus someone whom we – the readers – will need to correct if we believe the Socratic project to be fundamentally correct (cf. Howland 1998; Scodel 1987; Zuckert 2000).
Our view of the “philosophic” trial – and thus of who is properly a philosopher in the Platonic universe – will be significantly altered depending on whether we locate the main tension of the dialogue between Socrates and the Stranger or between philosophers (like Socrates and the Stranger) and non-philosophic others, including the mathematicians Theodorus and Theatetus.
I take it that Plato presents a substantive (though not personal) tension between Socrates and Theodorus and Theaetetus, who represent certain mathematical forms of thought (cf. Miller 1980, pp. 3-10). Despite their warm treatment of Socrates, they do not seem clearly convinced that he is not a vulgar sophist. For example, Theaetetus seems to agree that Socrates (or somebody who is much like Socrates) is a sophist at Sophist 231a4-5, even though he seems unaware of the consequences of his agreement; and Theodorus at various points seems to suggest that Socrates is not measured enough to be a philosopher (Theaetetus 169a6-b4, Sophist 216b7-c1). Theodorus in particular, like the Athenian demos, does not seem to understand the Socratic project of refutation as philosophical.
If the main tension in these dialogues is between the Eleatic and Socrates on the one hand and Theodorus and the mathematicians on the other, then the Eleatic dialogues can be read in part as meditations on the limits of mathematical knowledge, as we shall see.