Jeremy Reid's paper "Unfamiliar Voices: Harmonizing the Non-Socratic Speeches and Plato's Psychology" is forthcoming in the Cambridge Critical Guide to the Symposium (Cambridge University Press, edited by P. Destrée & Z. Giannopoulou).
Abstract: Two debates seemed to have reached an impasse in the literature on Plato's Symposium. In the first place, commentators are divided on whether Plato's conception of the soul implicit in the dialogue is simple or tripartite; moreover, they are divided on whether the speeches by characters other than Socrates contain material which is to be incorporated into Socrates' speech or corrected by it. This paper suggests that the first four speeches share similar psychological concerns as those that motivate the tripartite division elsewhere. Phaedrus explores how eros engages our thumoeidic capacities; Pausanias then explains how eros develops our capacities to act well qua lawfully (an important stage in the development of reason) and to aim at virtue; Eryximachus - signposted as being one place too early - follows with an account of the skillful production of harmony among conflicting elements; Aristophanes then gives an allegorical account of how the appetites have an appropriate (oikeion) object and can come to be ordered through submission to reason. This grouping of the early speeches also suggests an interesting epistemological unity in the later speeches: first, Agathon gives a speech whose content turns out to be almost entirely false; then, Socrates gives an account of the grounds of knowledge; finally, Alcibiades, swearing on five occasions to tell the truth, contrasts Socrates' steadfastness with his own fluctuating behavior, characteristic of those with untethered true beliefs. Thus we can see that the structure of the speeches of the Symposium is careful and deliberate, and suggests a greater similarity in Plato's thinking on eros across dialogues.