History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
For you would not only become auxiliaries to these, but also enemies to us, instead of being connected by treaty; for if you come with them, we must defend ourselves against them without excepting you.
And yet you ought, if possible, to stand aloof from both parties; or if not that, on the contrary, to go with us against them; (with the Corinthians, at any rate, you are connected by treaty; while with the Corcyraeans you were never yet so much as in truce;) and not to establish the law, that we should receive those who are revolting from others.
For neither did we, when the Samnians had revolted, give our vote against you, when the rest of the Peloponnesians were divided in their votes, as to whether they should assist them; but we openly maintained the contrary, that each one should punish his own allies.
For if you receive and assist those who are doing wrong, there will be found no fewer of your allies also who will come over to us; and you will make the law against yourselves, rather than against us.
"These, then, are the pleas of right which we have to urge to you, sufficiently strong according to the laws of the Greeks; and we have the following advice, and claim on you for favour, which, being not enemies so as to hurt you, nor, on the other hand, suck friends as to be very intimate with you, we say ought to be repaid to us at the present time.