History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
We ought, on the contrary, instead of rigorously chastising free peoples when they revolt, to watch them rigorously before they revolt, and thus forestall their even thinking of such a thing; and when we have subdued a revolt, we ought to put the blame on as few as possible.[*](In answer to Cleon's demand, 3.39.6.)
"And do you consider, too, how great a mistake you would make in another point also by following Cleon's advice.
At the present time the populace of all the cities is well disposed to you, and either does not join with the aristocrats in revolting, or, if forced to do so, is hostile from the beginning to those who stirred up the revolt; and so, when you go to war, you have the populace of the rebellious city as your allies.
If, however, you destroy the populace in Mytilene, which took no part in the revolt, and which voluntarily put the city into your hands as soon as it got hold of arms, in the first place you will be guilty of killing your benefactors, and, in the second place, you will bring about what the influential men most wish: the next time they instigate a revolt among our allies they will at once have the populace on their side, because you will have published it abroad that the same punishment is ordained for the innocent and for the guilty.