History of the Peloponnesian War

And as for what they severally advanced in speaking, either when about to go to war, or when already in it, it was hard to remember the exact words of what was said; both for myself, with regard to what I heard in person, and for those who reported it to me from any other quarters: but as I thought that they would severally have spoken most to the purpose on the subjects from time to time before them, while I adhered as closely as possible to the general sense of what was really said so have I recorded it.

But with regard to the facts of what was done in the war, I did not presume to state them on hearsay from any chance informant, nor as I thought probable myself; but those at which I was personally present, and, when informed by others, only after investigating them accurately in every particular, as far as was possible.