Plato presents Socrates as an ethical example and a political warning. Other characters serve other philosophical functions. Alcibiades--the worst man in the democracy--and Critias--the worst in the oligarchy--are the most notorious characters.. This dissertation argues that Plato uses these characters in order to open a diachronic dimension in the synchronic accounts of the dialogues. This dimension turns historical characters into paradigmatic characters and allows the reader to evaluate the accounts people give in terms of the lives that they lead. In order to make a case for philosophy, Plato needs to make it clear that bad accounts have negative ethical effects, particularly over a period of time. The use of paradigmatic characters lik...