History of the Peloponnesian War

Now as many of us as have already had any dealings with the Athenians require no warning to beware of them; but those who live more in the interior, and not in the high way of communication, ought to know, that if they do not defend those on the coast, they will find the carrying down of their produce [for exportation] more difficult, and the procuring again of those things which the sea affords to the mainland; and they ought not to be indifferent judges of what is now said, as though it did not affect them, but to consider that some time or other, if they should sacrifice the towns on the coast, the danger would reach even to them; and that they are now consulting for themselves no less [than for others].

And for this reason they ought not to shrink from passing to war instead of pence For it is the part of prudent men, indeed, to remain quiet, should they not be injured; but of brave men, when injured, to go from peace to war; and when a good opportunity offers, to come to an understanding again from hostilities; and neither to be elated by their success in war, nor to brook injury through being charmed with the quiet of peace.

For he who shrinks from this course for love of pleasure, would most quickly be deprived of the delights of indolence, for which he shrinks from it, should he remain quiet; and he who in war becomes grasping through success, does not reflect that he is buoyed up by a confidence that cannot be trusted.