History of the Peloponnesian War

For if we enter into a war and call in these men, who are apt enough to bring their army in uncalled, and if we weaken ourselves at our own charges and withal cut out for them the dominion here, it is likely, when they shall see us spent, they will sometime hereafter come upon us with a greater fleet and attempt to bring all these states into their subjection.

"Now, if we were wise, we ought rather to call in confederates and undergo dangers for the winning of somewhat that is none of ours than for the impairing of what we already have; and to believe that nothing so much destroys a city as sedition, and that Sicily, though we the inhabitants thereof be insidiated by the Athenians as one body, is nevertheless city against city in sedition within itself.

In contemplation whereof, we ought, man with man and city with city, to return again into amity; and with one consent to endeavour the safety of all Sicily: and not to have this conceit, that though the Dorians be the Athenians' enemies, yet the Chalcideans are safe, as being of the race of the Ionians.

For they invade not these divided races upon hatred of a side, but upon a covetous desire of those necessaries which we enjoy in common. And this they have proved themselves in their coming hither to aid the Chalcideans.