History of the Peloponnesian War

The Lacedaemonians, perceiving this stir to begin in Peloponnesus, and that the Corinthians were both the contrivers of it and entered themselves also into the league with Argos, sent ambassadors unto Corinth with intention to prevent the sequel of it: and accused them both for the whole design and for their own revolt in particular, which they intended to make from them to the league of the Argives, saying that they should therein infringe their oath and that they had already done unjustly to refuse the peace made with the Athenians; forasmuch as it is an article of their league that what the major part of the confederates should conclude, unless it were hindered by some god or hero, the same was to stand good.

But the Corinthians, those confederates which had refused the peace as well as they being now at Corinth (for they had sent for them before), in their answer to the Lacedaemonians did not openly allege the wrongs they had received; as that the Athenians had not restored Solium nor Anactorium nor anything else they had in this war lost; but pretended not to betray those of Thrace, for that they had in particular taken an oath to them, both when together with Potidaea they first revolted and also another afterwards.

And therefore, they said, they did not break the oath of their league by rejecting the peace with Athens. For having sworn unto them by the gods, they should in betraying them offend the gods. And whereas it is said unless some god or hero hinder it, this appeareth to be a divine hindrance.

Thus they answered for their old oath. Then, for their league with the Argives, they gave this answer:

that when they had advised with their friends, they would do afterwards what should be just. And so the ambassadors of Lacedaemon went home. At the same time were present also in Corinth the ambassadors of Argos to invite the Corinthians to their league, and that without delay. But the Corinthians appointed them to come again at their next sitting.