Thucydides on the national character of the Athenians: 
'The Congress of the Peloponnesian Alliance' (1.67-78)
(prompted by the conflict between Athens and Corinth over Potidaea and Corcyra)
The Athenians and Peloponnesians had these previous grievances against each other: the complaint of Corinth was that her colony Potidaea, with Corinthian and Peloponnesian citizens in it, was under siege; that of Athens against the Peloponnesians was that they had incited a town of hers, a member of her alliance and a contributor to her revenue, to revolt, and had come and were openly fighting against her on the side of the Potidaeans.
For all this, war had not yet broken out, and there was still truce for a while; for [the battle at Potidaea] was chiefly a matter for Corinth alone. But the siege of Potidaea drove the Corinthians to take the diplomatic initiative: she had men inside the besieged city, and she feared it would fall. Immediately summoning the allies to Lacedaemon, she came and loudly accused Athens of breaking the treaty and of aggression against the Peloponnesians. With her, the Aeginetans, though formally unrepresented from fear of Athens, in secret proved to be urgent advocates for war, asserting that they had not the independence guaranteed to them by the treaty. After extending the summons to any of their allies and others who might have complaints to make of Athenian aggression, the Lacedaemonians held their ordinary assembly, and invited them to speak. There were many who came forward and made their several accusations; particularly the Megarians, in a long list of grievances, protested that they were excluded from the ports of the Athenian empire and the market of Athens in defiance of the treaty.
Last of all the Corinthians came forward, and having let those who preceded them inflame the Lacedaemonians, now followed with a speech to this effect:
[Speech of the Corinthians: Stability breeds complacency]
'Lacedaemonians! because you are so trusting in your own constitution and social order, your are inclined to receive any complaints we make against other powers with a certain scepticism. From this confidence comes moderation, but also the rather limited knowledge which you betray in dealing with foreign politics. Time after time we have raised our voices to warn you of the blows about to be dealt us by Athens, and time after time, instead of taking the trouble to determine the truth of our claims, you simply suspected the speakers of serving their own interests. And so, instead of calling these allies together before the blow fell, you have delayed until the damage is already done. Among such allies we have the best right to speak, since we have the greatest complaints to make, complaints of Athenian outrage and Spartan indifference.
'Now if these assaults on the rights of Hellas had been made in the dark you might be unacquainted with the facts, and it would be our duty to enlighten you. As it is, we do not need to make long speeches to prove our point, since you see servitude already imposed upon some of us and theatening others--our own allies, in particular--and the aggressor is already well prepared against the hour of war. Or what, do you suppose, is the meaning of their taking sides with Corcyra by fraud, and their holding it against us by force? What of the siege of Potidaea?--Two strategic places: one the gateway to Thrace; and the other possessing a very large navy, which the Peloponnesians could have used?
'For all this you are responsible. It was you who first allowed them to fortify their city after the Persian war, and afterwards to erect the long walls. You who, then and now, are robbing of their freedom those whom Athens has enslaved, and who have as yet been your allies. For the party who is truly to blame for the subjugation of a people is not so much the immediate aggressor, as the power that tolerates aggression when they can prevent it; particularly if that power aspires to the glory of being the liberator of Hellas. We are at last assembled. It has not been easy to bring us together, nor even now are our objectives clearly defined. We ought not to be still inquiring into the fact of our wrongs, but into the means of our defence. For the aggressors, who have far advanced their plans in the face of our indecision, have now cast threats aside and betaken themselves to action. And we know what are the paths by which Athenian aggression travels, and how insidious is its progress. Athens has gained a degree of confidence from the idea that you were too slow to notice; but that confidence is nothing compared what she will show when she realizes that you see [what is going on] but do not care to interfere.
'You alone, Lacedaemonians, of all the Hellenes keep still, and defend yourselves not by doing anything but by looking as if you would do something; you alone wait until the power of an enemy is becoming twice its original size, instead of crushing it in its infancy. And yet the world used to say that you were to be depended upon; but in your case, we fear, it is so in word more than in truth. The Persians, we know, had time to come from the ends of the earth to your very borders, without any force of yours worthy of the name advancing to meet him. But this was a distant enemy. Well, Athens at all events is a near neighbor, and yet Athens you utterly disregard; against Athens you prefer to act on the defensive instead of on the offensive, and to make it an affair of chances by deferring the struggle until she has grown far stronger than at first. And yet you know that on the whole the rock on which the barbarian was wrecked was himself, and that if our present enemy Athens has not again and again annihilated us, we owe it more to her blunders than to your protection. Indeed, relying on you has before now been the ruin of some whose faith induced them no to prepare for the worst. 'We hope that none of you will consider these words spoken in hostility rather than honest complaint. Men make complaint with friends who go wrong; for their enemies they reserve condemnation. Besides, we consider that we have as good a right as any one to point out a neighbor's faults, particularly when we contemplate the great contrast between the two national characters; a contrast of which, as far as we can see, you have little perception, having never yet considered what sort of antagonists you will encounter in the Athenians, how widely, how absolutely different from yourselves.
 'The Athenians are addicted to innovation, and their designs are characterized by speed, both in planning and execution; you have a genius for keeping what you have got, accompanied by a total reluctance to make any change, and when forced to act you never go far enough. Again, they are adventurous beyond their power, and daring beyond their judgment, and in danger they are sanguine; your inclination is to attempt less than your could achieve, to mistrust even what your own judgment tells you is so, and to imagine that there is no escape from danger. Further, there is readiness-to-act on their side, against procrastination on yours: they are (always involved in some undertaking), never at home; you are never away from home. For they hope by their absence to extend their gains; you fear by your advance to endanger what you have left behind. They are swift to follow up a success, and slow to recoil from a reverse. Their bodies they exhaust ungrudgingly in their country's cause; their intellect they jealously husband to be employed in her service. A scheme they have not carried out is with them an outright loss, a modest success is a comparative failure. Whatever they lose ... is soon filled up by fresh hopes; for they alone are capable of regarding a thing that they hope to achieve as a thing they have already got, so quick are they to act on their decisions. Thus they toil on in trouble and danger all the days of their life, with little opportunity for enjoying, being ever engaged in getting: their only idea of a holiday is to do what the occasion demands, and to them laborious work is less of a bother than peace and quiet. To describe their character in a word, one might truly say that they were born into the world to take no rest themselves and to give none to others.
'Such is Athens, your antagonist. And yet, Lacedaemonians, you still delay, and fail to see that peace stays longest with those, who are not more careful to use their power justly than to show their determination not to submit to injustice. On the contrary, your ideal of fair dealing is based on the principle that if you do not injure others, you need not risk your own fortunes in preventing others from injuring you. Now you could scarcely have succeeded in such a policy even against a neighbor like yourselves; but your disadvantage is all the greater in the struggle ahead, inasmuch as your habits are outmoded by theirs. It is the law in politics, just as in technology, that innovation ever prevails; and although unchanged practices may be best for settled communities, where action is a constant necessity, it must be accompanied by constant improvement in methods. So it is that the diverse experience of Athens has carried her far ahead of you on the path of innovation.
'Here, at least, let your procrastination end. For the present, assist your allies and Potidaea in particular, as you promised, by a speedy invasion of Attica, and do not sacrifice friends and kindred to their bitterest enemies, and drive the rest of us in desperation to ally with anyone who will help us. Such a step would not be condemned either by the gods who received our oaths, or by the men who witnessed them. The breach of a treaty cannot be blamed on the people who are compelled by their losses to seek new allies, but the blame rests with those who fail to support their allies. But if you will only take action, we will stand by you; it would be unnatural for us to change, and never should we meet with such a congenial comrade. For these reasons choose the right course, and endeavor not to let Peloponnesus under your supremacy degenerate from the prestige that it enjoyed under that of your ancestors.'
Such were the words of the Corinthians. There happened to be Athenian envoys present at Sparta on other business ....They thought themselves called upon [to speak in defense of their city] to show on a comprehensive view that [the question of war or peace] was not a matter to be hastily decided. They also desired to call attention to the great power of Athens and to remind old and young alike [of Athenian triumphs]. . .
[Speech of the Athenians]
'The purpose of our coming here was not to argue with your allies but to attend to the matters for which we were sent by our city, but the violence of the outcry against us has prevailed on us to come forward. It is not to combat the accusations of the cities against us [that we speak out], but to prevent your taking the wrong course on matters of great importance by yielding to readily to the persuasions of your allies. We also wish to show on a review of the whole indictment that we have a fair title to our possessions and that our country deserves fair consideration. We need not refer to ancient history...but to the Persian War and recent history. In our action in that war we ran great risk to obtain certain advantages: you had your share in the solid results, so do not try to rob us of all share in the good that the glory may do us. However, the story shall be told not so much to plead against hostilities as to testify against them, and to show, if you are so ill-advised as to enter into a struggle with Athens, what sort of an antagonist she is likely to prove. We assert that at Marathon we were at the front and faced the barbarian single-handed. When he came the second time [under Xerxes], unable to cope with him by land we went on board our ships with all our people and joined battle at Salamis. This kept the enemy from taking the Peloponnesian states one-by-one...The best proof of this was given by the invader himself: defeated at sea, he considered his power to be no longer what it had been, and retreated as quickly as he could...
'Such then was the outcome and it was clearly proved that the fleet of Hellas was her salvation. To this we contributed three essential elements: the largest number of ships, the ablest commander, and the most unhesitating patriotism. Our contingent was almost two-thirds of the whole four hundred ships; in command was Themistocles who was chiefly responsible for the strategy of fighting in the straits, which proved the salvation of us all; ...and for our valor we had no rivals. Receiving no reinforcements by land, seeing all around us already conquered, we had the spirit to abandon our city, sacrifice our property, throw ourselves into our ships and face the danger... We claim then that we contributed (at least) as much as we received, for you still had possession of your land to fight for...but we left behind a city that was a city no longer and staked our lives for a city that had an existence only in desperate hope, and so we bore full responsibility in your deliverance and our own. ...
'Surely, Lacedaemonians, neither by the patriotism that we displayed at that crisis nor by the wisdom of our counsels do we merit the resentment against us among the Hellenes, not at least for our empire. That empire we acquired by no violent means but because you were unwilling to prosecute the war to its conclusion and because the allies voluntarily joined us and asked us to assume command. The very nature of events first compelled us to raise our empire to its height, fear being our principal motive, though honor and self-interest came into it. And at last when almost all hated us, when some had already revolted and had been conquered, when you had ceased to be the friends you once were, ...it appeared no longer safe to give up our empire. especially since all who seceded from us would join with you. And no one can quarrel with a people for making the best provision in its own interest in matters of [survival].
'In any event, you, Lacedaemonians, have used your hegemony to manage the cities in the Peloponnesus as you please. And if [in the aftermath of the Persian war] you had persevered in your command, undoubtedly you would have been as hateful to the allies and would have been forced to choose between strong authority or more hazardous leniency. Therefore it is no wonder nor anything out of the ordinary practice of mankind that we accepted the empire when it was offered to us and have refused to give it up, under force of three of the strongest motives--fear, honor, and self-interest. It was not we who set the example, but it has always been so, that the weaker should submit to the stronger. And we believed that we deserved the authority we held and thought that others regarded us as worthy--until now, when considerations of self-interest have made you take up the rallying cry of 'justice' (a moral standard that no one ever put in the way of his own ambition...).
' Respect is due to those who, if not so superior to human nature as to refuse power, yet have more regard for justice than their position makes necessary. So we believe that our own fairness would be best demonstrated if others were put in our position. But even our pursuit of fairness has earned us condemnation rather than approval. [Because we relinquish any unfair advantage in contract disputes with our subjects, but require that cases involving our citizens and our allies be tried at Athens], we have gotten the reputation of being litigious. [And no one bothers to consider the unequal jurisdictional rules that other imperial powers impose on their subjects.] Our subjects are so habituated to associate with us as equals, that any reversal whatever offends their sense of right... Men's indignation, it seems is more excited by a legal imposition than a violent wrong! A legal defeat feels like being cheated by an equal, while a forceable wrong seems like being compelled by a superior. In any case, [some of those who condemn us, managed to put up with much worse when they submitted to Persian domination]. . . .
' This at least is certain: if you were to succeed in overthrowing us and in taking our place, you would quickly lose the popularity which opposition to us has given you, if your present policy were to follow the example of your brief hegemony against the Persians. For the rules and values you observe in your own country are unlike those of other Hellenes [and your character is therefore unsuited to rule over them]; and, what is more, when your leading citizens campaign abroad, they [are easily corrupted] and neither obey your rules nor those recognized by the rest of Hellas. Deliberate upon this momentous decision, therefore, with all due consideration, and do not be persuaded by the views of others to bring hardship upon yourselves, but weigh the vast uncertainty of warfare before you venture into it. War all too often becomes a matter of chance, and Chance cannot be evaded by any of us. In going to war, men commonly go on into disaster before they consider [how to extricate themselves from it]. ...
' Accordingly, while we can still make decisions rationally, we urge you not to dissolve the treaty or break your oaths, but to have our differences settled by arbitration, as stipulated in the agreement. Otherwise, we call upon the gods who heard those oaths to bear witness, if you make a beginning of hostilities, whatever strategy you use, [with all our will] we shall oppose you.' [The Athenian speech only served to provoke greater resentment, and the majority of the allies agreed that Athens was the aggressor and war must be declared against her. The Spartan king Archidamus, to the contrary, spoke in favor of caution and restraint, foreseeing a long and exhausting war, doubtful of success--"Never let us be carried away by the fatal delusion that the war can be quickly won [by laying siege to Athens and plundering her territory]. I fear rather that we may leave it as a legacy to our children [i.e. that the war will continue into the second generation], so improbable is it that the Athenian spirit will be slave to their land..."
[Nonetheless the vote is for war, and Thucydides assesses the motives: "not so much because they were persuaded by the allies as because they feared the growing power of Athens, which already dominated most of the Greek world." ]