That characters exist in Thucydides, and that their distinctive traits influence historical action, cannot be disputed. Themistocles' wit and effectiveness are first displayed (I. 90–3, I. 135–8) and then described (I. 138. 2–3). The traits that made Pericles a great statesman are affirmed, as are the personal qualities that determined Cleon's influence (II. 65, III. 38. 6, V. 16. I). We are also given an explicit statement that Alcibiades' character proved harmful to Athens by alienating public trust (VI. 15. I), while later passages imply that Nicias' personal stubbornness hurt the expedition in Sicily (VII. 48. 3, VII. 50. 4).

The general outlines of the roles of Nicias and Alcibiades in Thucydides are clear, and, while differences of opinion exist as to the precise motives of these men, the importance of their characters is undeniable. It is also undeniable that the speeches are a major source of information about these men. In Nicias' speeches, for instance, we are given strong arguments for hesitation and conservative ἀπραγμοσύνη, while Alcibiades' exhortation to the Athenians urges action and defends the speaker's competitiveness.

Despite the general admission that characters are important in Thucydides, and the agreement that their speeches provide insight into them, modern scholars insist that these speeches show no individuality of language. Thus Friedrich Blass says: ‘spricht nun der Athener wie der Lakedaimonier, Perikles wie Kleon und Brasidas, was die Form der Rede und den Ausdruck anbelangt’.