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.
“Alcidas, and you who, like myself, are present here as commanders of the Peloponnesian forces, it seems to me that we should sail to Mytilene before our approach becomes known, without a moment's delay.
For in all probability we shall find that men who have but lately come into possession of a city are very much off their guard. At sea, indeed, they will be altogether so, where they have no expectation of any possible hostile attack and our role is chiefly to act on the defensive;[*](Or, “while on our side it is just here that our strength lies.”) and on land also their forces are probably scattered among the houses all the more carelessly because they believe that they are victors.