In writing his history as a whole, it is fair to say that Thucydides has always been praised for his relative historical accuracy, be that due to his actual presence at events, his use of eyewitness testimony or his noted checking of facts. In style Thucydides kept his narrative sections rather impersonal thereby allowing the story to unfold itself. However, to then lay bare what stood behind the narrative, the moral possibilities, the mistakes, the fears and the motives, the device he used was the speech, a mechanism he employed with supreme mastery.
Perhaps the best way to begin to answer the question in hand, we should examine the definition Thucydides himself gives us in his statement of methodology for his speeches that appears in 1.22.1. of his History of the Peloponnesian War.
‘In this history I have made use of set speeches some of which were delivered just before and others during the war. I have found it difficult to remember the precise words used in the speeches which I listened to myself and my various informants have experienced the same difficulty; so my method has been while keeping as closely as possible to the general sense of the words that were actually used, to make the speakers say what, in my opinion, was called for by each situation’’
It is not unreasonable to construe that at face value this statement is not at all a ringing endorsement for historical accuracy. This idea is taken up by Plant who correctly states that there is a lack of correlation between the first and second parts of the statement. He continues that it has long been debated whether the historian claimed and/or attempted to present verbatim accounts of the arguments put forward by the speakers on each occasion as best he could, or whether he felt free to modify or to invent particular arguments or even whole speeches. And the controversy has been
fuelled by what has been widely regarded as the...