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.
The victory of the Syracusans having now proved decisive by sea also—for before this they had always been afraid of the new fleet that had come with Demosthenes—the Athenians were in utter despondency. Great had been their miscalculation, and far greater still was their regret at having made the expedition. For of all the cities with which they had gone to war, these alone were at that time similar in character to their own, democratic in constitution like themselves, and strong in ships, cavalry and size.
And so, finding themselves unable either to bring about a change in their form of government,[*](It was the usual policy of Athens to overthrow oligarchies and establish democracies as a means of extending their empire; but this resource was not open to them in democratic Syracuse.) and thus introduce among them that element of discord by which they might have brought them over to the Athenian side, or to subdue them by means of a military force that was greatly superior, and having failed in most of their undertakings, they had even before this been at their wits' end, and now that they had suffered defeat even with their fleet, a thing that they could never have anticipated, they were in far greater perplexity still.
The Syracusans, on the other hand, began at once to sail fearlessly about the harbour and determined to close up the entrance to it, in order that the Athenians might no longer be able, even if they wished, to sail out unobserved.
For the Syracusans were no longer concerned with merely saving themselves, but also with preventing the Athenians from being saved, thinking, as indeed was the case, that in the present circumstances their own position was much superior, and that if they could defeat the Athenians and their allies both by land and by sea the achievement would appear a glorious one for them in the eyes of the Hellenes. All the other Hellenes, they reflected, would immediately be either liberated from subjection or relieved from fear, since the military forces that would remain to the Athenians would not be strong enough to sustain the war that would afterwards be brought against them; and they themselves, being regarded as the authors of all this, would be greatly admired not only by the world at large but also by posterity.