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.

and as for their spirit, it was not to be endured if they, being Peloponnesians and Dorians, confronting Ionians and islanders and a mixed rabble, were not going to make it a point of honour to conquer them and drive them out of the country.

After this, when there was a favourable opportunity, he led them on again. Now Nicias and the Athenians thought that, even if the Syracusans were unwilling to begin fighting, they themselves could not possibly look idly on while the wall was being built past their own—for already the enemy's wall had all but passed the end of the Athenians' wall, and if it once got by, from then on it would be all one to them whether they fought and conquered in every battle or did not fight at all— accordingly they advanced against the Syracusans.

And Gylippus, leading forth his hoplites more outside the walls than before, closed with the enemy, having his cavalry and javelin-men posted on the flank of the Athenians, in the open space where the work on both walls ended.