SOURCE: "The Imperialist Impulse," in Herodotus, Explorer of the Past: Three Essays, Princeton University Press, 1991, pp. 9-40.

[In the following essay, Evans discusses Herodotus 's treatment of the causes of the Persian invasion of Greece, focusing on the imperialist motives of Xerxes, the fall of Croesus, and the concepts of nomos, aitia and fate that colored Herodotus's account of the Persian Wars.]

Nine years after their defeat at Marathon, the Persians were ready once again to invade Greece. The Greeks owed a debt of gratitude to Egypt for the delay. For three years after the defeat, Darius had prepared a new assault to wipe out the disgrace, but then Egypt had risen in revolt, and in 486 b.c., Darius died; Xerxes succeeded him and the rebellion was not crushed until 484. Then Xerxes called a synod of the Persian magnates. It was a congress that Herodotus recreated with imaginative skill, but there may be a solid morsel of tradition behind it: in the romance of Esther, King Ahasuerus (Xerxes) summoned his nobles to a great festival in the third year of his reign, but in the Hebrew tradition these festivities were merely a backdrop for the fall of Vashti and the elevation of the Jewish heroine Esther in her place. For Herodotus, the feasting and the pageantry that must have accompanied a congress of this sort were of no importance: the synod is treated merely as a bit of theater for a remarkable exposition of the motive force behind Persian imperialism. Herodotus has undertaken to explain the reasons why Xerxes chose to invade Greece.

Persian despots were not given to parliamentary procedures. Herodotus reported in another context that the Persians debated questions drunk, and reconsidered them sober, or vice versa, as the case may be, but he portrayed no councils of the sort for his readers. He made short shrift of the debate that took place before Darius' Scythian expedition. "While Darius was making ready his invasion of Scythia and dispatching messengers round about with orders to some to raise troops, to others to supply ships and still others to build a bridge over the Thracian Bosporus, Artabanus, son of Hysptaspes, Darius' brother, urged him strongly not to make the expedition against the Scyths, on the ground that Scythia was a difficult objective. But good as his advice was, he failed to convince and he ceased." So much for the counsel that Darius was willing to accept before he set out against the Scyths. Cyrus did better before he advanced across the river Araxes against the Massagetae: he called a council of his "first men," and all but one advised him to allow the queen of the Massagetae to move into Persian territory and fight a decisive battle there. The exception was Croesus, who had lost the throne of Lydia and taken over the persona of a wise adviser instead. He argued that to advance was both safer and more appropriate for a Persian king: therefore Cyrus should move forward into the queen's territory and use trickery to defeat the Massagetae on their soil. The result of this strategy was, first, the capture and suicide of the queen's son, and then the death of Cyrus himself in battle. There is nothing approaching the cut-and-thrust of a full-scale debate here, but only a topos that provided an opening for a wise adviser to make a point, and for the hero of the tale, Cyrus, to make an existential choice.

In fact, if we except the famous debate of the Persian grandees on the question of the proper constitution for Persia, which is more influenced by the sophists (particularly Protagoras) than anything in the Persian tradition, there is only one other assembly in the Histories which is comparable. That is the council at Phaleron before the battle of Salamis. There the king took his seat; then the various princelings and squadron commanders took theirs in order of rank: the king of Sidon first, next the king of Tyre, and so on in order. Mardonius went around to each to put the question whether or not to fight. All voted for battle, except the irrepressible Artemisia, the only commander in the Persian force with an intelligence comparable to Themistocles', who delivered a brief address to Mardonius, and he in turn reported it to Xerxes. Dissent was handled with courtesy and decorum, and then dismissed: a stark contrast with the councils of the Greek admirals before Salamis. Xerxes accepted a majority verdict which, not surprisingly, agreed with his own inclination, and chose the wrong course of action, whereas the Greeks did otherwise.

This Persian council was the inverse counterpart of the conclaves of the Greek admirals, and it was hardly more than a little showcase that Herodotus used to parade the might-have-beens of history before his readers' eyes. He chose as his mouthpiece Artemisia, a woman, and therefore an outsider in this masculine assembly. But the speeches of Xerxes, Mardonius, and Artabanus before the Persian magnates at the king's levee are intended to reveal something of the substance of Persian imperialism as Herodotus understood it.

The king at first had not possessed any great wish to invade Greece. He did not initially feel the weight of Persia's imperial tradition, or the obligation to expand the frontiers of the empire. The chief instigator of the war was Mardonius, son of Gobryas, who had taken command of Persia's Aegean front in 494 B.C.; Herodotus implied that he owed his elevation then, at a young age, to his "recent" marriage to Artazostra, Darius' daughter. He had advanced into Europe as far as Mt. Athos, where he had lost three hundred ships and twenty thousand men in a tempest, and was wounded himself in a night attack on his camp by a local tribe, the Brygoi. Not a glorious achievement overall.

But Mardonius had not returned home before conquering the Brygoi, his wound notwithstanding, and his influence with the new king was paramount. Convinced of Persian superiority, and quite without any comprehension of the Greeks, he was to be the spokesman for aggressive imperialism, who still believed that no Greek would dare "look without flinching at Persian dress and the men who wore it," to take a phrase from Herodotus, who wrote that, before the battle of Marathon, a Greek would not have summoned the courage to do any such thing. "Indeed my lord, who will oppose you and offer war, when you bring with you the host of Asia and all your ships?" he asked.

Events are to change his mind not one iota. In his last speech before his death, he was to gloat that the retreat of the Spartans on the battlefield of Plataea demonstrated their inferiority. He pressed his advice upon the new king. Athens, he argued, had committed great crimes, and had to be punished. She had helped the king's Ionian subjects to rebel, and then at Marathon, she had humiliated Datis and Artaphrenes. Vengeance was necessary for the sake of security: Athens had to be punished so that no one in the future would dare invade the Great King's dominions.

But that was not all. Europe was beautiful: a fertile land with trees of every kind. Mardonius stood the truth as the Greeks perceived it on its head, for the contrast between Persian wealth and Greek poverty was commonplace in classical Greece. Pausanias, son of Cleombrotus, staged a tableau to illustrate this after the victory at Plataea, and at the end of the century, Xenophon was to tell his ten thousand mercenaries that they must get back to Greece to tell their friends and relatives that they were poor by their own choice, for if they migrated to Persia, they could live in luxury. Mardonius reversed the polarity that the Greeks accepted as conventional wisdom. But Mardonius also harbored an ulterior motive: he wanted to be governor of Greece himself.

He had assistance in this endeavor. The pro-Persian Aleuad family, dynasts of Larissa in Thessaly, seconded his efforts; in 479 B.C., after the defeat at Salamis, they were still to urge the Persians on to their ultimate defeat at Plataea. The deposed Pisistratid tyrant Hippias had guided the Persians to Marathon in 490 B.C., and died soon thereafter; who the new pretenders were, we do not know, but Herodotus considered the Pisistratid lobby still effective at the Persian court, and it included a kresmologos, Onomakritos, a collector and editor of oracles who provided a selection of prophecies predicting Persian success. Xerxes let himself be persuaded by a team made up of an ambitious courtier, self-interested Thessalian aristocrats, and the lobby for a discredited dynastic family driven from Athens three decades before.

Thus far, the new king of Persia had appeared in the Histories as a shallow prince, the victim of his own naivety, but no great imperialist. He was, in fact, in his mid-thirties when he came to the throne, and he had already shown himself to be more ruthless and bigoted than his father, but his portrayal by Herodotus is otherwise. Yet his speech to the Persian magnates presents a new dimension, for he proceeded to enunciate the principles of imperialism that actuated the empire which he had inherited.

First, expansionism was a Persian nomos, and not a new one. "I learn from our elders that we have never remained inactive since we took over this sovereign power from the Medes, when Cyrus deposed Astyages." It was a nomos sanctioned by Heaven, and it brought Persia greatness and prosperity. Second, there was the example of Xerxes' predecessors who had followed this nomos. Cyrus, Cambyses, and Darius had added to the empire, and so must Xerxes too. Greece still remained outside it, and, echoing Mardonius' mis-representation of the truth, Xerxes pronounced Greece as large and as rich as Persia itself: the intended victim of Persian aggression was Persia's equal. Last, there was the motive of revenge. Athens should be punished for the wrongs she had inflicted on Persia. Yet vengeance seems a secondary cause, for Xerxes' ambitions went far beyond Athens. If Europe and Asia were yoked, Xerxes could make them one country. The world would have one monarch. There would be no limits to the realm of the Great King, and hence, we may note, no boundaries left to transgress. Thus, said Xerxes, downgrading the guilt of Athens as a motive, those who were aitioi and those who were not would both be enslaved. With that, Xerxes invited debate.

The dialectic that follows is uneven. Mardonius was outclassed by the king's uncle, Artabanus, whose role as a wise adviser urging caution has already been foreshadowed: he had tried similarly to dissuade Darius from his Scythian expedition. Mardonius has less to say; his points are comments on the king's speech, and his purpose was to soften its rough edges. The Ionians living in Europe could not be allowed to make fools of the Persians: the outrages committed at Sardis and Marathon had to be avenged. Yet, Mardonius pointed out that vengeance had played no role in Persia's expansion thus far. Persia's previous victims had done her no wrong. But that made the argument for invading Greece all the stronger, for now that Persia did have a just cause for war, it would be extraordinary if she failed to exploit it. In any case, the Greeks were poor fighters and their knowledge of military tactics puerile. They would not resist, but if they did, they would discover that the Persians were the best soldiers in the world. With that, Mardonius concluded with a wry note of irony: he gave Xerxes the conventional warning against overconfidence.

One of these arguments we have met before. Aristagoras of Miletus, who was also a fomenter of war, had tried the inverse of it on the Spartans: the Persians, he said, were not valiant men, and their weapons and armor were inadequate. It was a war hawk's standard argument. Herodotus himself, on the first point, granted the Persians valor equal to the Greeks, but on the second point, he agreed with Aristagoras.

Yet a new overtone has emerged. Herodotus' judgment on the Ionians was unflattering, though we should not overemphasize, for he makes exceptions. Yet his general assessment is explicit. Of all the Hellenes, the Ionians were the weakest. Their only city of importance was Athens, and she did not like to be called "Ionian." Cleisthenes, whose reforms had started the growth of Athens to power, had established new tribes that had no counterpart among the Ionians out of contempt for them. The reason for Herodotus' assessment is another story; here we should note merely that the Persian miscalculation of the Greek will to resist was founded on their familiarity with those Greeks under Persian dominion. This included not merely the Ionians but the Dorians and Aeolians as well, though to the Persians they were all Yauna, nor did Herodotus himself think it always necessary to differentiate. They were a quarrelsome lot: those benefitting from Persian rule had been forced after the Ionian Revolt to settle their differences by arbitration rather than war, but the free Greeks settled theirs by choosing a level parcel of ground and fighting it out. In any event, Xerxes had no fears that the Ionians would be anything but obedient subjects until his defeat at Salamis, after which it occurred to him that they might instigate the Greek fleet to sail to the Hellespont and destroy the bridges there. The stature of the Ionians led the Persians to underestimate all the Greeks. In any assessment of the causes of Xerxes' invasion, the poor reputation of the Ionians had something to answer for.

Only one Persian dared to present the opposing view: the king's uncle, Artabanus. He is a dramatic figure whose ultimate archetype is Cassandra. More than a wise adviser, he is almost a seer whose accurate vision of the future introduced a note of dramatic irony. The Greeks were valorous, he said, shifting the gaze of the magnates from the subject Ionians to Athens: at Marathon, the Athenians alone had vanquished the great army of Datis and Artaphrenes. Suppose the Greeks defeated the Persians on sea and then destroyed the bridge over the Hellespont? He cited Darius' Scythian expedition as a parallel: when Darius was forced to retreat, all that stood between him and disaster was the resolve of one Greek, Histiaeus of Miletus: for a few hours, the future of Persia had rested upon the shoulders of this one man. Therefore Xerxes should not act rashly; he should reflect at leisure, and Artabanus seemed confident that reflection would result in inaction.

He went on, developing an argument that Solon had put to Croesus at the height of his power. "My lord Croesus," Solon had said, "I know that all Heaven is jealous, and loves to create mischief and you ask me about the fortunes of men!" Heaven loved to smite the great, warned Artabanus, unconsciously drawing the parallel with the Lydian king, and God endured presumption in no one but Himself. He concluded with nothing less than a confident wager on a Persian defeat: let him and Mardonius both stake their children's lives on the outcome of the expedition! If it was a success, Artabanus' line would be wiped out.

The king replied wrathfully, full of dynastic pride. The war was a necessity; vengeance had to be exacted from the Athenians. "I know well that if we remain at peace, they will not; they are sure to invade our country!" The expedition had become a preemptive strike: Persia must attack or herself be attacked. There was still, of course, the example of the past, though Xerxes dredged Greek mythology for a specious parallel: if Pelops the Phrygian could conquer Greece, could not the Great King too, who counted the Phrygians among his slaves?

The story is quickly concluded. At night, Xerxes did rethink, and decided that Artabanus was right. His anger, as he was to explain to the Persian council the next day, was the hot temper of youth. Then Xerxes was visited twice in dreams by a phantom: a tall, handsome man, who also visited Artabanus. The message was always the same: Xerxes would countermand the expedition at his peril. The penalty for remaining at peace would be the loss of his royal status. "Be, then, very sure of this," said the phantom, on its second visit, "if you do not launch your war at once, this shall be the outcome: just as a brief span of time raised you to be great and mighty, so shall you speedily become humble again." The reader may note that the apparition failed to promise victory, though even Artabanus imagined that a successful outcome was implied. But the message was unavoidable: Xerxes had to invade Greece or face an unpleasant alternative.

Years ago, Macan remarked that the analogy between Xerxes' dream and the deceitful dream sent to Agamemnon in the Iliad has "often been pointed out." But though Herodotus has borrowed the literary device, he has shifted the emphasis. The dream in the Iliad is a simple case of a mischievous god playing with the overconfident Agamemnon, exploiting a weak point in his character by promising him victory without Achilles' help. The dream of Xerxes was not explicitly deceitful, for it did not presage a Greek defeat, though it left that impression. Instead it emphasized the danger of trying to reverse what was destined to be. It was Xerxes' position as king of Persia, the descendant of a line of Achaememid imperialists who had increased the size of the empire during their several reigns, that circumscribed his freedom of action. All. the reasons Mardonius had given for invading Greece and Artabanus' rebuttals did not matter. Xerxes seems to be caught, all unknowing, in a dilemma of fate and free will, quite as much as the protagonist of Sophocles' Oedipus Tyrannus. Xerxes was intended to invade Greece, and the dream intervened when he seemed on the point of falling short of what Bernard Knox, in his study of Oedipus, calls "the divine intention." But it is fair to ask why there should be any such "divine intention" at all. What forces were there at work that forestalled Xerxes' impulse to draw back from disaster?

THE NECESSITY OF REVENGE

One thinks naturally of vengeance and retribution. The concept appears frequently in the Histories. Retribution (tisis) was a way of evening up the score, or paying off someone to whom an obligation was due, and it served the function of enforcing a kind of equilibrium in a macrocosm of contrapositions. Its near synonym, timoria, could mean "assistance" as well; in the Hippocratic writings, it might mean simply "medical aid." Xerxes told the assembled magnates that tisis and timoria were among the by-products of his expedition; the mention is casual, but as he went on, he elaborated. The vengeance-motive centered around the twenty ships that Athens sent to help the Ionians in their revolt against Persia; Herodotus calls them the "beginnings of evils for the Greeks and the barbarians." The phrase has the Homeric echo that Herodotus liked to evoke, but it was almost a cliché, and we should not give it undue significance: the aid that Athens and Eretria sent the rebels was a provocation which reawakened Persia's aggressive instincts, but it was not the real cause of her expansionism. Mardonius referred to the vengeance motive, but with a cynical twist: Persian imperialism had developed and progressed thus far without it, he said, for the various peoples whom the Persians conquered had done Persia no wrong; but now, when the Persians did possess a vengeance motive, it would be too bad if they failed to exploit it! Vengeance was a good reason for imperial expansion if there were grounds for it, but if there were not, the impulse that drove imperial aggression could make do without it.

As an alleged cause of action, the importance of vengeance in the Histories cannot be denied. It could hardly be otherwise. Retribution was part of the moral and intellectual baggage that Herodotus had inherited from the epic and the whole tradition of Greek mythopoeia. "Famine and blight do not beset the just," wrote Hesiod. Zeus exacted great penalties from proud men who worked evil. On the level of popular theology, Herodotus was not far removed from that view. He recorded that, in the general opinion of the Greeks, Cleomenes, king of Sparta, went mad as retribution for sacrilege (the Spartans were the exception: they attributed his madness to heavy drinking). But Herodotus himself thought his insanity was retribution for his unjust treatment of Demaratus. Talthybius exacted retribution for the Persian heralds whom the Spartans killed in 491 B.C., and the whole story of the Trojan War, reflected Herodotus, as he compared the Egyptian account of it with Greek legend, was a revelation of how the gods exacted great penalties for great wrongdoing.

This theological mindset left its mark in the world of diplomacy as well. "You started this war," the Spartans told the Athenians in the spring of 479 b.c., when Mardonius tried to entice them into a separate peace, "and we had no wish for it. The struggle began as a war for your territory and now it involves all Greece." In the Spartan view of things, the Athenian intervention in the Ionian Revolt began the war. It was a starting point, which led directly to Xerxes' invasion. But nowhere does Herodotus suggest that Persian aggression would never have taken place if the Athenian contingent of twenty ships had not set sail for Ionia in the first year of the revolt!

Alleged causes might serve very well as justifications, but they were not necessarily real causes. Darius remembered the Athenian part in the Ionian Revolt: he assigned a slave the task of reminding him of it, but Herodotus labels it a prophasis: a prior injury that can be put forward to justify revenge. It was only his ostensible motive for the dispatch of Datis and Artaphrenes to Marathon; his real intention was to conquer all of Greece that had not surrendered to him by giving earth and water. And finally, Herodotus states his own view of the matter, which by implication rejects vengeance for the twenty ships as the cause of the war. The expedition of Xerxes, he says, was nominally against Athens, but in fact its objective was to subjugate all of Greece. The Athenian intervention was never more than a provocation, and when such provocations were available, Persian imperialism might exploit them as pretexts, but when they were not, it continued on its course equally well without them. Herodotus does not display the cynicism about allegations of prior wrongs used to justify aggression that Thucydides evinces, but he seems merely to have included them among the tactics of war.

Darius' Scythian expedition is a case in point, which illustrates how useful a tactic the prophasis of vengeance could be. Darius' motive for the expedition against Scythia was revenge for an ancient wrong, but in the same breath Herodotus adds the economic argument for expansion: Asia was full of wealth and population: hence the time was ripe to put this casus belli to practical use. The Scyths, faced with the invasion, sent envoys to their neighbors to seek help. They argued that the Persian motive for aggression was not revenge but simple appetite for conquest: otherwise the attack would have been directed against the Scyths alone, and Darius would have ignored the Getae and the Thracians whom he swept up along the way. The reply was mixed: some agreed to help but more rejected the Scythian argument, replying that the Persians were really reacting to an unprovoked wrong, the Scythian conquest of Asia that had lasted twenty-eight years. A god had presided over the Scythian rule of Persia as long as he had ordained it, and now the same god presided over the interaction of vengeance and countervengeance. These neutrals felt confident that they would suffer no harm from Darius if they did him none. "However," they added, "if he enters our land and starts doing us wrong, we shall not put up with it."

This exchange is close to a parody of the diplomatic efforts that the Hellenic League made to find allies against Xerxes, and on one point it twists historical accuracy. It was the Medes, not the Persians, whom the Scyths had conquered. Herodotus pretends that the neutrals saw Darius' attack within the larger context of chronic strife between Europe and Asia, a premise that makes the parallel between the Scythian expedition and Xerxes' invasion all the closer. And in the answer of the neutrals to the appeal of the Scyths for help, there is an echo of the debate in Greece over the responsibility for the Persian attack. Darius could allege vengeance, though he had to delve back into history and distort it a bit to find a wrong that merited retribution, but this vengeance motive served well enough to justify his attack that it partially aborted the Scythian effort to form an alliance against him.

But it is affluence that Herodotus puts forward as the premier cause. "For, as Asia was at its flower in numbers of men, and great wealth was coming in, Darius conceived the desire to take vengeance on the Scyths." This is not Herodotus speaking as a modern economic historian, nor is it an example of a tragic pattern, where koros leads to blindness, and blindness to a fall. Darius returned safely from Scythia, having established Persian authority in the north Aegean area. Rather, Herodotus is stating simply that the possession of power, measured in population and revenue, is a stimulus to imperial expansion. The Scythian act of aggression that Darius decided to avenge was not pure fiction: alleged causes rarely are. Their purpose is to shift the blame away from the perpetrator of the aggressive act, and they would serve it poorly if they were patently false. But they mask the true reason.

Miltiades, after the victory of Marathon, led an attack on Paros, and he had a well-founded prophasis: Paros had contributed a trireme to the fleet of Datis and Artaphrenes. But he also had a private motive, which Herodotus is careful to point out. Aryandes, satrap of Egypt, dispatched an expedition against Cyrene, and his pretext was vengeance for the murder of Arcesilaus. Yet Herodotus considered it merely an excuse to conquer Libya, for it was full of tribes and most of them paid Darius no attention.

Vengeance, therefore, was a respectable justification for aggression, and Heaven deemed it satisfactory, as the neutral neighbors of the Scyths reminded them. It was equally acceptable in the Athenian law courts, where the strict relevance of what was being avenged was not required. But ostensible causes were not to be confused with real ones. Xerxes might retort wrathfully to Artabanus that Persia must attack or be attacked, but he forgot the point once his anger had cooled. The dream that visited Xerxes did not tell him that he had to avenge wrongs inflicted by the Athenians on the Persians; it stressed instead the consequences if he did not. Xerxes' mission went beyond vengeance. As he told his magnates, he wanted to subdue both the aitioi and anaitioi to slavery.

This conclusion, that on the level of international politics, vengeance served more as an alleged cause than as a real one, is all the more remarkable because in two other spheres Herodotus did regard vengeance as a causal agent. On the divine level, he believed that the gods exacted retribution. The Persians under Artabazus' command who were drowned by an unusually high tide as they assaulted Potidaea, suffered retribution for desecrating Poseidon's temple. So the Potidaeans said, and Herodotus agreed. The Aeginetans who put down the uprising of Nicodromus and killed the rebels who sought asylum in the temple of Demeter, suffered vengeance before they could obtain divine mercy: they were driven from their homes in the first year of the Peloponnesian War. Divine vengeance fell also upon the Pelasgians for murdering and raping Athenian concubines.

But this was popular theology that was generally accepted, and Herodotus did not dispute it, for it made sense out of what would otherwise be irrational. In instances such as the madness of King Cleomenes of Sparta, there might be a difference of opinion about the particular sin for which the sinner suffered retribution, but Herodotus had no doubt that his madness was retribution from the gods. But vengeance on this level fell within the province of Heaven, and could be recognized clearly only after it had taken place. Then men might look back and discern (or think they discern) the offense for which the gods had meted out condign punishment. But the reasons why men acted as they did, and the motives that impelled them, belonged to the human space.

The other level, where Herodotus recognized the working of vengeance, is what we may call the realm of natural science, which had engrossed the Presocratics. The winged snakes of Arabia that guarded the frankincense bushes would have overwhelmed mankind but for the design of divine providence. The female killed the male after he had impregnated her, and suffered retribution for it, for her offspring avenged their sire by chewing their way out of her womb, thus killing her. In this way, divine providence prevented the snakes from growing too numerous and overwhelming their enemy, mankind. This is vengeance operating as a natural force to maintain balance within the sphere of biology, and to our eyes, it seems completely amoral; but perhaps not to Herodotus or his contemporaries, for whom the universe itself was a moral construct, and thus we cannot make a sharp distinction between natural science and the divine. The vengeance that controlled the population growth of the winged snakes seems to be the same sort of retribution to which Heraclitus referred when he said that the sun would not overstep its measures, for if it did, the Furies would find it out, and before Heraclitus, Anaximander of Miletus had seen the same force as a law of nature. The earliest, and perhaps the most lasting influence upon Herodotus was the thought-world of Ionia, and when Xerxes crossed the Hellespont, the reader of the Histories must sense that the natural boundary between Europe and Asia that was defined by the logioi of the proem has been overstepped. For Herodotus, even the geographical space within which human action occurs is commensurate and balanced, evidently reflecting in some way the mandate of justice. But did some inexorable law of nature demand that Xerxes avenge the outrages that Persia had suffered at Sardis and Marathon, thereby making him overstep the natural limits of Asia and opening him in turn to retribution?

Herodotus avoided any such conclusion. The dream of Xerxes merely warned him of the consequences that he would suffer if he canceled his expedition. It was Artabanus who thought it promised success: he had imagined that Xerxes would have a happy reign if he remained inactive, but "since there is some divine impulse, and some destruction sent from Heaven has fallen upon the Greeks, I of myself change my mind and abandon my view." But Artabanus assumed more than the dream told him. The divine message was simply that Xerxes could not turn aside from what had to be.

The restricted choice of Xerxes resembles the choices that Sophocles allows Oedipus, but is the force that restricts it an iron law that demanded vengeance upon the Greeks? The evidence seems to point in another direction: whatever the directing power of vengeance might be in the dark workings of fate and destiny, on the human level of everyday international affairs, it was neither a natural force nor a divine law. Rather, it was a debating point: a justification for a policy that recommended itself for other reasons.

This was the conclusion of a shrewd observer of his own times, who saw the contemporary world without illusions. Vengeance as justification for imperialism was a leitmotiv of the fifth century. Revenge on the Medes was the advertised purpose of the Delian League: for that we have Thucydides as witness, though Herodotus, following another tradition that fitted his detached cynicism better, attributed Athenian imperialism to an innate desire for hegemony that antedated Xerxes' invasion. An outside observer might have seen a chain of vengeance and countervengeance continuing from the Ionian Revolt right down to the date of publication of the Histories, following a kind of Hegelian dialectic that saw the opposition between the Persian Empire and the Hellenic League replaced by one between the centers of power in Greece itself. In public discussion retribution served as a respectable motive for aggression; thus, in the winter of 432-431, Sparta put together a list of grievances perpetrated by the Athenians to justify the Peloponnesian War. But it was not the guiding force of imperialism. When Cyrus undertook to extend his empire to annex the Massagetae, his motives did not include revenge. Rather, Herodotus suggests two: first, his birth, which made him superhuman in men's eyes, and second, his success in war. The first had to do with the psychology of kings, and the second with the psychology of empire: the reputation of Persia as a successful imperialist power, which Cyrus had created and which now drove him forward. The satrap Oroetes killed Polycrates of Samos out of wounded pride: his fellow satrap Mitrobates had taunted him with failing to bring Samos into the Empire. Polycrates had done Oroetes no wrong, and Oroetes sought no vengeance. He slew Polycrates to prove himself a worthy expansionist of the empire in the Persian tradition.

It is instructive to make a comparison with Thucydides. The Athenian envoys in Sparta who addressed the assembly of the Peloponnesian League in 432 B.C. made an attempt to state the reasons for Athenian imperialism. "We did nothing surprising nor contrary to human custom," they said, "if we accepted the rule (arche) that was given to us, and do not let it go, for we are conquered by overwhelming motives: honor, fear and profit." The persona of the Persian king did not admit fear, but what of profit? Thucydides assumed that imperial exploitation for gain was a fact of nature. But Greece was poor, and in Greek eyes, Pausanias, the son of Cleombrotus, made the defintive judgment on the profit motive: Xerxes' passion to add what few possessions Greece had to the wealth of Persia was proof of his utter lack of sense. The Persians had well-developed acquisitive instincts. Atossa told Darius that she wanted to add women from the leading states of Greece to her attendants, and Mardonius extolled the fertility of Greece, and its variety of trees. But both really acted from personal motives.

For the most part, Herodotus saw the economic causes of expansionism working in a different way. For him, the increasing resources of the imperialist power itself, resulting from growth of population, prompted it to look beyond its borders, and the wealth of the people it proposed to subjugate was unimportant, to the extent that Pausanias could make no sense out of it. Thus, power grew avid for more power, and in Herodotus' view, the profit motive seems to play only a small role in Persian expansionism. But the third motive—honor—was a different matter.

The king's pride and honor were constant factors, along with the requirement that he appear a restless and ambitious man of energy. This was the reputation of Cyrus and of the Medes before him. They would not keep still. "It is not proper, my lord, for the Athenians, who have done the Persians many wrongs, not to pay retribution for their deeds," said Mardonius, urging his logos timoros upon the still-reluctant Xerxes. But he developed his argument with a point that deserves particular attention. "Invade Athens, so that you may have a good reputation among men, and anyone in the future will have a care before he makes war upon your land." The king had to maintain his reputation. "I formed the opinion," said Artabanus, admitting his error to the king, "that if you kept still, in the eyes of all men you would be happiest." But Xerxes could not be a lesser man than his predecessors, for he had to maintain the integrity of the Great King's persona as a competent ruler who could not be challenged with impunity. Contempt of a ruler led to rebellion, as Aristotle was to point out: the dignity and reputation of Xerxes defended both his empire and his own position as king, and both might suffer if he allowed a wrong to go unavenged. To that extent, Xerxes was governed by the vengeance motive, but this was no iron law of retribution that directed his actions: rather, it was a simple axiom of statecraft. A king had to sustain his prestige if he was to maintain his status.

NOMOS AS EXPLANATION

Xerxes began his speech to the Persian magnates with a significant statement: "Men of Persia, this nomos I set before you is not one that I am the first to put forward; it is because it has been handed down to me that I make use of it." For Thucydides, imperialism was part of human nature; it was natural for the strong to exploit the weak. For Herodotus, expansionism was a nomos, and therefore, if we want to understand it, we should look at an empire's nomoi. Imperialism, therefore, fell within the field of ethnology, which was Herodotus' initial interest.

Nomoi, which Havelock once translated correctly, if somewhat awkwardly, as "custom-laws," bulk large in the Histories, and we should define what we mean by the word. First, what it is not: it is not the antithesis of physis. In one instance, Herodotus could couple the two concepts in one breath: those Greeks were ignorant, he states, who accepted the silly myth that told how Heracles, upon his arrival in Egypt, was led out to be sacrificed, and at the altar turned on his captors and slew them in vast numbers. The purveyors of this tale knew nothing of the physis and nomos of the Egyptians, and anyway, it was contrary to nature (physis) for a single mortal to kill such great numbers. It was not that Herodotus thought of physis and nomos as synonyms; rather, the nomoi of a nation were the outgrowth of its physis. A report could not be authentic if it failed to conform to the nomoi of the people it purported to portray, for their nomoi were rooted in their nature, and thus possessed an integrity that could not be disregarded.

Physis was in no sense a technical word: it might refer to the appearance of the hippopotamus, the life cycle of the crocodile, or the physical stature of man—all qualities over which man (or the crocodile or hippopotamus, as the case might be) has no control. There is also such an entity as human physis: the "nature of man," which defined human competence, as Cambyses discovered to his cost. He slew his brother Smerdis because, in a dream, he saw a messenger come from Persia to tell him that Smerdis was on the throne, and then he learned of the revolt of the magos by the same name, and realized that he had acted with greater haste than wisdom, "for it is not in the physis of mankind to turn aside what is going to be." The natural condition of mankind was constrained by limits that were beyond the power of even kings to change.

Yet those limits did not rule out choice. Before the battle of Salamis, Themistocles told his sailors that in the nature and constitution of men (physis and katastasis), there were some qualities that were better and some that were worse, and he urged them to choose the better. What Themistocles wanted his men to choose was the quality that would drive them forward into battle, and that quality might be expressed as a nomos. At least we may conclude as much from the discourse of Xerxes with the exiled king of Sparta, Demaratus, who equated the nomos that required the Spartans to take up arms with the royal power that compelled the Persian troops to fight.

Thus, though men might not alter their physis, within the limits it set, they could make choices, and their nomoi were based on a choice, or a series of choices that they, or their ancestors had made. Herodotus has broken almost completely with the ancient view that nomoi were ordained by Heaven. To be sure, he reported the tradition that Lycurgus took the Spartan nomoi from Delphi, but the Spartans themselves said that he borrowed them from Crete, and there is the implication that the Spartans were the weightier authority. Gyges explained the origin of nomoi to Candaules: mankind had found out in the past by trial and error what was lawful and unlawful. In much the same way, Hippocrates explained how primitive man discovered by trial and error what was good to eat and what was not: he experimented with all sorts of foods, raw and cooked, and learned to avoid those that made him ill. In like manner, the Lydians had discovered that viewing another man's wife naked was not lawful, and Gyges begged Candaules not to insist that he do it. But Candaules was bound by an evil destiny. And when Cambyses in Egypt laughed at Egyptian nomoi, Herodotus saw it as a symptom of madness.

For nomoi possessed authority. Every people preferred its own, and if given a chance to choose, would not exchange them for those of another people. Yet it was a mark of wisdom to respect alien nomoi, and recognize their authority. Herodotus quotes a gobbet of Pindar which is later quoted more fully by Plato. "Nomos is king of everything," but quite out of context. Pindar spoke of nomos as justification for the right of the powerful to use violence against those who were weaker. Callicles in the Gorgias used the quotation to support the argument that Xerxes acted in accordance with the nomos based on nature that allowed the strong to seize the possessions of the weak. But Herodotus wanted only to show that nomoi exercised quasi-despotic power. Xerxes, bedazzled by the sheer bulk of his host, summoned Demaratus and asked if the Greeks would dare resist. Demaratus would speak only for the Spartans whom he knew, but they at least would fight, even though they had no despot to force them. "For though they are free," he said, "they are not free in everything, for nomos is over them as master, which they fear in their hearts more than your people fear you." Xerxes, like Cambyses, laughed.

There is a degree of irony to the failure of Xerxes to understand the import of what Demaratus had to say, for the Persian borrowed alien customs most readily of all men, and yet their kings failed to comprehend the authority of nomoi. Cambyses' reaction was laughter, while Xerxes dismissed Demaratus with tolerant amusement. At Marathon, the Persians thought the Greeks were mad when they charged them; at Thermopylae Xerxes was angered by their impudence and suicidal folly; and at Artemisium, the Persian captains considered the Greeks demented. Before Salamis, Xerxes had come to realize that his great host had failed to live up to his expectations, but he believed the reason was that he himself had not been present to inspire his men. This failure of the Persians to comprehend the nomos that commanded the Greeks to resist is a leitmotiv which continues as far as their defeat at Plataea, where Mardonius led his men in a disorderly pursuit of the Spartans, imagining that they were running away!

Yet the Persians themselves were actuated by a nomos too—one that forbade them to remain inactive. "Men of Persia," Xerxes said to the assembled Persian notables, "I am not myself setting up this nomos among you to follow, but it is one I have inherited, and I shall use it. I learn from our elders that we have never remained inactive since we took over this sovereign power from the Medes, when Cyrus dethroned Astyages. It is a god who leads us on." An imperial regime never remained still; it was always stirring with ambition. Nitocris had recognized this quality in the Medes, the Babylonians recognized it in Cyrus, and years later, on the eve of the Peloponnesian War, the Corinthians are to point it out as the disposition of imperial Athens. An ancestral nomos directed the Persians always to push on and maintain the momentum of expansion. Xerxes thought that they were led by a god, but he was wrong: nomoi in the Histories evolve on the human, not the divine level, and the nomos that brought Persia her empire was based on deliberate choice quite as much as any other custom. Xerxes' conviction that the nomos of expansionism had divine sanction was myopic. It was a symptom of blindness.

There are two pertinent stories in the Histories that make clear how the Persians acquired and maintained their nomos of imperialism. The first tells how Cyrus persuaded the Persians to revolt from the Medes. He summoned an assembly of Persians and set them to work clearing a parcel of land overgrown with weeds. The next day, he gave them a sumptuous banquet. Then he asked which they preferred: the toil that was the lot of a subject, or the good life of a ruler. They chose the latter.

The second story concludes the Histories. The Persians have made their choice, and have acquired the nomos of imperialism and an empire to go along with it. A Persian noble named Artembares suggested to Cyrus that the Persians leave their own rocky and infertile native land, and choose another from among their dominions, where life would be easier. Cyrus allowed his Persians a choice. But first he taught them a percept borrowed from the Hippocratic school of medicine: soft lands breed soft men, better fitted to be subjects than rulers. The Persians chose to rule, and remained where they were. This nomos of imperialism was a harsh master, and the story of Cyrus that ends the Histories has palpably ironic overtones, for by the fifth century, the Persians had long since abandoned the hard life, but the nomos of imperialism still drove them forward.

After the defeat at Salamis, Mardonius, the war hawk at the meeting of the magnates, continued to remain faithful to this nomos. He carried on where Xerxes left off, all the more determined because he had urged the expedition upon a disinclined Xerxes in the first place, and hence would have to bear some responsibility for its failure, if it should come to that. He was by no means pessimistic: "his judgement actually inclined him to think that he would subdue Greece," to quote Grene's translation of Herodotus' cautious, ironic Greek. At Plataea, he was still eager to push forward and start the fight: in the council before the battle, he was uncompromising, urging his commanders to pay no attention to the negative omens produced by their sacrifices made according to Greek rites, but instead to abide simply by the Persian nomos and attack.

His last words were charged with irony. He was full of overconfidence: the Spartans had seemingly fled and he would make them pay for the wrongs they had committed. The Persian nomos of never keeping still but always pushing forward led him in the end to disaster. He was already a marked man; Xerxes had appointed him to make amends for Leonidas' death (which Delphi had demanded), and at Plataea the ironic purport of that appointment becomes clear: it was Mardonius, not the Spartans, who had to pay for the wrongs that had been done.

Some two decades ago, I wrote an article which examined the connection between the role of nomos and causation in the Histories. In his proem, Herodotus states a two-fold purpose: he had the praise-poets' concern to impart renown to the exploits of the warriors in both camps, and the philosopher's concern to find the reason for the conflict. I concluded that the reason (for which Herodotus uses the equivocal word aitia) could not be discovered among Persian nomoi, but that the nomoi of a people did expalin their course of action, and consequently understanding nomoi was a mark of wisdom. In any given situation, one might expect a people to behave according to its nomoi. I have not abandoned that view, for nomos does serve as an explanatory principle, but I gave insufficient weight to nomos as a governing force. The nomos of ambition and restlessness that Xerxes inherited from his forebears exercised a directing influence over his policies which is akin to the "divine intention" in the Oedipus Tyrannus. It did, therefore, supply a reason why he had to attack Greece.

Perhaps Xerxes might have paid no attention to this nomos of expansionism, and adhered to the decision he had reached upon reconsideration. But the weight of tradition was against him: it was appropriate for a Persian king who was young and master of great wealth to achieve something worth notice, as Queen Atossa had told Darius in a bedroom conversation that led to Persia's first expedition to Europe. The cost of refusing to invade Greece would have been great. The apparition that appeared to Xerxes threatened him with loss of this throne. It did not promise victory, although Xerxes and Artabanus inferred it. Rather, its message was that there was a high price to be paid if Xerxes failed to follow this nomos of imperialism which the Persians had chosen years before, when Cyrus had given them a choice—and then it had been a free choice. Herodotus did not treat imperialism itself as an expression of human nature, as Thucydides did, but rather as a nomos that is elected freely, but once chosen, cannot be abandoned without cost. The Persians had followed their chosen nomos with good fortune thus far, and now Xerxes was governed by it.

The Greeks were equally directed by nomos. Wisdom and nomos were the basis of the courage with which they resisted both poverty and despotism. Demaratus' attempt to explain this to Xerxes proved futile, and yet the nomos that directed the Greeks to fight possessed as much authority as the Great King himself. But Xerxes could not understand. The power and glory of Persia's monarchy had brought her kings to the point where they found the nomoi of other people at best amusing. This incomprehension was a kind of blindness, and, as the outcome of the Persian Wars was to prove, it was a dangerous state of mind.

THE CONCEPT OF GUILT

Any reader of the first sentence of Herodotus' proem must wonder what part he assigned to war guilt as a factor working its way through the strands of history, for he concludes with a statement that he was looking for the aitia of the conflict. The word aitia, or in the Ionian Greek of Herodotus, aitie, occurs fifty-one times in the Histories, Twenty-two times, the meaning is fault, blame, or the sort of charge a plaintiff might launch in a court of law, and an equal number of times it can be translated simply as "cause," though the cause can imply a degree of blame. There are a few remaining instances, but they do not help to resolve the ambiguity. What, for instance, can we make of Herodotus' tale of the bond that existed between Cleomenes of Sparta and Cleisthenes' rival, Isagoras? "Aitia had Cleomenes going into (i.e., having sexual intercourse with) the wife of Isagoras." Aitia here is an accusatory morsel of gossip, not, to be sure, without moral connotations, which people suggested as the reason for the claim Isagoras had upon Cleomenes.

Or let us take another example: the aitia of Cambyses' attack on Egypt. "Cambyses, son of Cyrus, made an expedition against Amasis … for an aitia of such a kind as this." Aitia here, Powell assures us, means "the reason why." Then follows the story of how Cambyses demanded Amasis' daughter as wife, which he did at the instance of an Egyptian eye doctor whom Cyrus had demanded from Egypt. The verb "to demand" is aitein, and there may be a play of words here between the aitia that means "the reason why," and the demands that brought about this reason: the aitia of the Persian invasion was the response of the pharaoh to Cambyses' demand, and hence by reciprocation this demand develops into a cause. Yet at the same time, the aitia was a charge that Cambyses brought against the pharaoh.

Finally, there is the use of the word in the proem. It carries the suggestion that someone was to blame for the war, and the debate of the logioi develops upon that assumption. Yet, at the same time, it looks forward to the common usage of aitia among the philosophers of the fourth century B.C., where it is the synonym of the Latin causa, meaning "reason," "motive," or "inducement."

Guilt is closely tied to vengeance, and it may be argued that the two concepts should not be separated. But in a Greek court, guilt had to be established before punishment could be applied, and, to quote Arthur Adkins, "In Greek there can be no phonos (violent death) without someone being aitios phonou (guilty of murder). The same should be true of the supreme act of violence, war. Some person or thing should be guilty of it, and ordinarily the guilty party should be the one that initiated the war. Thus, as I have argued, it was to shift guilt to the targets of aggression that invaders alleged retribution.

Given the opening sentence of the Histories, we might be excused for imagining that the concept of war guilt bulked large in his thought. But this was not so. Herodotus gives first a Persian story of how strife between Europe and Asia began, and this story is marked by a pronounced distinction between being "guilty" and "greatly guilty." The Phoenicians incurred guilt first by kidnapping Io, but the Greeks were guilty to the second power by mounting a military expedition, the Trojan War. The Phoenicians have a gloss to add to the story, but that is all. Then Herodotus dismisses this speculation and the logic that went along with it, and chooses his own starting point: the imperialist action of the king of Lydia, Croesus.

His existence was solid enough: there were his dedications at Delphi to attest it. He was more than a mere aggressor. Earlier Mermnads had attacked the Greeks, but Croesus established a polity that exacted tribute from them, thus fitting the definition of empire. Upon succeeding his father to the throne, Croesus moved first against Ephesus, and then against the other Ionian and Aeolian cities one by one, putting forward various aitiai, the best he could find, though some of them were trivial indeed. Nevertheless, Herodotus imagined that Croesus sought to assign some guilt to the Greek cities to justify his aggression: "He brought different aitiai against various cities: important ones when he could find them, but against others he brought aitiai that were truly slight." These aitiai were accusations: hardly more than stratagems to shift the burden of guilt, and they did nothing to explain the real motive of Lydian imperialism. Herodotus himself preferred to present Croesus within a tragic framework: he was a great king whose imperialism was the outgrowth of his wealth and prosperity: his consequent power and affluence resulted in blindness, which in turn allowed him to blunder into fatal error. He attacked a people toughened by a hard life, whose poverty could add little to his wealth even if he were victorious. Herodotus has sunk his teeth into a traditional tale here, but it sets a pattern, and his aim in telling it is moral as much as it is historical.

The story of Croesus seems to present the rise and fall of empire in parvo: a sort of paradigm of imperial development that suggests comparison with the career of Xerxes. But it leaves us little wiser about the aitia of the Persian Wars. The reason for Croesus' fall, according to Delphi, was bound up with moira; Croesus was expiating Gyges' sin after five generations, which was the portion of time allotted to his dynasty. According to Herodotus, whose view does not quite tally with Delphi's, "great nemesis overtook Croesus, as one would guess, because he thought himself the most blessed of all men." So Croesus had fallen for two reasons: moira, because he had reached the end of an allotted span established before he was born, and nemesis, for which he bore some guilt himself: he considered himself more fortunate than a mortal should.

These are two separate concepts that are uneasily coupled here. Just how uneasy the coupling is, becomes apparent in another instance: the men of Paros consulted Delphi on the proper punishment for the priestess Timo, who had attempted to betray them to Miltiades, and received the reply from the Pythia that she was blameless, for Miltiades was doomed to a bad end, and Timo was only the instrument of his fate. Similarly, Apollo did not accept any blame for Croesus' fall. Indeed, he went so far as to argue that Croesus himself was blameworthy. The oracle had warned him that he would destroy a great empire if he attacked Cyrus, but he had failed to ask which empire was meant. Croesus had taken care to test the reliability of the oracles, but when it came to the central issue, his astuteness was clouded by his egocentrism and overconfidence. So much for Delphi's view of Croesus' guilt.

At whose feet, then, should the guilt for the Persian Wars be laid? I have already argued that the motive of revenge did not account for Persian imperialism. Their conquests took place equally well with or without it. Herodotus was as skeptical of Persia's aitiai as he was of those that Croesus put forward. But the conventional wisdom which no logios could ignore without provoking comment from his audience had it that Athens had incurred guilt by intervening in the Ionian Revolt, thus committing an unprovoked wrong. Given the Greek concept of guilt, followed (when proven) by retribution, it was arguable that Athenian guilt caused the Persian attack. Quite unfairly, punishment that should have fallen on Athens alone involved all Greece. That, at least, was how the Spartans viewed the matter: they were innocent bystanders, whereas Athens had stirred up the war.

Herodotus thought that Darius, angry as he was with the Athenians for their part in burning Sardis, nonetheless used their intervention in the revolt only as a pretext, and the war hawk Mardonius refers almost cynically to the guilt of the Greeks as he develops his case for Xerxes' invasion. Yet on the actual question of guilt, Herodotus seems to lean toward conventional wisdom. The twenty ships that Athens sent to help the Ionians were the beginning of evil in the sense that they started a fresh chain of events which led directly to Xerxes' invasion. Herodotus found it quite possible to accept that point of view, and at the same time, recognize that they were not the real reason for the onslaught. The Ionian Revolt deserved faint praise, and the Athenian decision to intervene showed how easily a democracy could be gulled by an adventurer like Aristagoras. But as Herodotus saw it, the troubles (which began with Naxos and Miletus, and expanded into a revolt thanks to Aristagoras and Histiaeus) served to revive the restless expansionism of Persia, and the twenty ships that Athens sent to help the rebels channeled it in the direction of Greece. To that extent, Athens was aitios. She made Greece an immediate objecive of Persia's imperialism. Thus, Herodotus did not altogether reject the Spartan view of the matter even though he was at pains to point out that Xerxes' expedition was only ostensibly directed against Athens; in fact, its object was all Greece.

The search for who or what was to blame for the war, which Herodotus announced in his proem, runs to ground. To take him literally, the primal aitia for which he could vouch, belonged to Croesus, who was the first to wrong the Greeks by making them tributary, which was the mark of empire. But Croesus' legacy was taken over by Persia, which followed its own imperative, and whatever interlinked chain of causes Croesus started, it mattered little as a reason why Xerxes invaded Greece. His aim was to subdue guilty and guiltless alike, and although Athens might be guilty in the limited sense that she attracted the attention of a king who had already expanded into Europe, the expedition of Xerxes was within the tradition of Persian expansionism.

There was, therefore, little purpose in asking who was to blame for the war. Blame might serve as a debating point or as a gambit in diplomacy, or as a satisfactory notion to give point to a story illustrating a historical pattern, but it did not explain the motive force behind Persian imperialism. A keeper of tradition might assign guilt for the war to this party or that, sometimes with a degree of justification, but guilt did nothing to explain the motive force behind Persian imperialism.

I suspect that this was a verdict which Herodotus reached not without hesitation, first because a good portion of Greece thought otherwise, and second because Herodotus shared the Greek attraction to tragic patterns in history. His story of Croesus is a case in point. The primal aitia was Candaules' wayward resolve to display his wife, naked, to Gyges, and from this aitia a chain of cause and effect led to Croesus' final expiation of an ancestors' forgotten wrong. Yet the causes and effects did not become apparent until after Croesus' fall, when the underlying pattern at last became clear. This was the sort of moral template that Herodotus' listeners expected him to use in his reconstruction of what happened when Persia expanded into Europe: an act of violence, in this case war, implied a guilty party that was to blame for it. The Greeks were familiar with the pattern, both in the theater and in the lawcourts. One feels that Herodotus would have been not unhappy if he had found some such design in Persian history. It would have provided easy explanations. But in fact, Herodotus made no consistent effort to discover who was guilty of causing the war, in spite of his announced intention in his proem, for it had no bearing upon the fundamental cause of Persian expansionism.

THE FATE OF THE PERSIAN EMPIRE

Finally, there is the question of fate. To what extent was Persian imperialism and its consequences governed by fate? It needs little imagination to discover tragic patterns in the Histories that compare with those we find in Oedipus Tyrannus or the Antigone, and crossfertilization is more than possible: the friendship of the two men is documented well enough. Herodotus makes more than the occasional obeisance to the dark workings of necessity. Candaules commanded his bodyguard Gyges to view his wife naked, because it was necessary for things to turn out badly for him. Candaules was a foolish king; yet it was necessity that decreed his false step. It was not merely the consequence of his own lack of wisdom. At the end of the Histories, Herodotus said very much the same about a royal scion as unwise as Candaules, Xerxes' daughter-in-law, and niece, Artaynte. Things were bound to turn out badly for her and her house. She acted foolishly, but her action conformed to a foreordained pattern.

There are other examples scattered throughout the Histories. The Naxian expedition that served as prologue to the Ionian Revolt was a failure because Naxos was not fated to fall to the Persians at that point in time. It fell later to Datis without a blow because the Naxians remembered the futility of their earlier resistance! Fate accomplished the dethronement of Demaratus, king of Sparta. Skylas, the Scythian king who was initiated into the Dionysiac rites, was fated to end badly. His adoption of Greek rites was a prophasis that served to explain why the Scyths revolted from him; but at a deeper level, fate directed events. The pharaoh Apries, whose subjects rebelled after his defeat in Cyrene, was also a casualty of fate: the disastrous attack which he launched against Cyrene, took place so that fate could work itself out. Miltiades, the victor at Marathon, was destined to come to a bad end. Finally, Herodotus appears to make an explicit acknowledgment of the omnipotence of fate. He related a story told by Thersander of Orchomenos, who attended a banquet given by the Theban medizer, Attaginus, for Mardonius and fifty Persian nobles before the battle of Plataea. The Persian who shared Thersander's couch told him in tears that few of the banqueters would survive. Men could not turn aside what God had decreed. Many of the Persians—so said Thersander's companion—knew what the outcome would be, but they were bound by necessity. "Thus, out of the darkness, the hand of divine superiority guides the destinies of humanity, the will and behaviour of men, according to its own purposes."

The quotation comes from Erwin Rohde's Psyche, and refers to the fates of Deianeira in the Trachiniae and Oedipus in Oedipus Tyrannus. Fate as inexorable as any that dogged Oedipus seems to close in upon Mardonius at the end of the Histories, so much so that Sir John Myres once argued that it is he who should be seen as the tragic hero of the last three books. Herodotus, who professed trust in oracles, used them skillfully to show how Mardonius was trapped by necessity. He discovered an oracle which predicted that the Persians would plunder Delphi and then perish; therefore the Persians would not plunder Delphi, and nothing would prevent their victory. But Mardonius had misunderstood; the oracle did not refer to the Persians at all. However, the oracles had not been silent, for there were prophecies of Bacis and Musaeus that Mardonius overlooked, which did foretell the Persian defeat. Mardonius, who more than any other Persian embodied Persia's imperialist impulse, could not for all his acumen escape his destiny.

Finally, we return to the dream of Xerxes. He assumed that he was free to launch an invasion of Greece or not, as he saw fit. Then, out of the dark, of night, he was told that he was not a free agent, and even Artabanus, after seeing the vision, withdrew his objection, imagining that some daimonie horme awaited the Greeks. Was there a "hand of divine superiority" behind the imperialist thrust of Persia?

The question is fair to ask, and the answer cannot be an easy one. Herodotus, who disagreed with the creeping cynicism of his day about oracles that we find in Thucydides, held up a prophecy of Bacis as an example of oracular accuracy. This oracle attributed the Persian defeat to "divine Dike" which quenches Koros, the son of Hybris. There is a close parallel in the second stasimon of the Oedipus Tyrannus: there Hybris begets Koros, and the result is disaster. Sophocles' chorus here portrays the traditional unrighteous man who is the victim of Hybris, Koros, and Ate. Guilt which is described in this Aeschylean fashion does not sound like the involuntary guilt of a man who has acted in ignorance. The oracle of Bacis which Herodotus quotes does not suggest any such thing, and since Herodotus held up this oracle as an example of divine prescience, I do not think he saw it that way either. At some point, the Persians had made a choice.

In fact, what must impress the reader of the Histories is the number of times that individuals are presented with choices that they must make. The clearest of these are placed in the Histories before the battles of Marathon and Salamis, and they are introduced with the same words. "It lies in your hands, Callimachus, whether to enslave Athens or keep her free," said Miltiades before Marathon; and before Salamis, Themistocles put the choice equally sharply to Eurybiades: "It lies in your hands to save Greece." In both instances, men who deserved the label "makers of history" approached relative nonentities and told them that the choice was theirs. They could decide whether or not Greece would be free. But these are only the most dramatic choices. The Ionians who guarded the Danube bridge for Darius on his Scythian expedition had a choice to make, and they could make it freely without incurring guilt, for they had done their duty and remained at their post for as long as they had pledged. Their leaders debated the question, first supporting Miltiades and then switching their support to Histiaeus, after he had pointed out to them where their own interests lay. Thus, the Ionians chose servitude.

Once again, before the battle of Lade, the Ionians faced a similar choice. Dionysius of Phocaea put it to them with a flourish borrowed from Homer: "Our affairs are on the razor's edge." The consequence of the choice was important: there could be no doubt of it, and the Ionians repeated the response they had made at the Danube bridge. They rallied at first to the cause of freedom and then they changed their minds.

Before Cyrus launched his Persians on the path to empire, he showed them the advantages both of servitude and imperial power, and let them choose. They chose imperialism. Even Gyges, who brought a curse upon the Mermnads that destroyed Croesus' empire after five generations, was given a choice. The queen summoned him and laid before him the alternatives. "There are two roads before you, Gyges, and I give you your choice which you will travel." It was a grim choice: Gyges might kill his king and usurp the throne, thereby incurring guilt, or die himself. But it was a choice nonetheless, and Gyges chose to survive and become king.

These situations where men are faced with alternatives are analogous to the tragic choices of Aeschylus: Pelasgus in the Suppliants faced such a choice, and the plot of the Agamemmon hung upon a choice made by Agamemnon at Aulis ten years before the story represented by the play began. "In Aeschylus," writes Bruno Snell, "the hero's choice becomes a problem whose solution is contingent on nothing but his own insight, but which is nevertheless regarded as a matter of compelling necessity." The choice once made might be hard to unmake, or it might not. Athens judged it natural enough that Sparta should fear that she might accede to the overtures which Mardonius made her in the spring of 479 B.C., but the Athenians themselves believed there was only one answer they could give. Yet in all these cases, the act of decision seems to be entirely within the human sphere of action.

The situation in which Xerxes found himself when he chose to invade Greece appears to differ. He first announced his resolve to undertake the expedition, confident that he could choose to make it or not as he pleased, and Artabanus gave his counsel in the belief that Xerxes could countermand it. Then an apparition in a dream warned Xerxes that his choice was limited, and when the same apparition visited Artabanus, it threatened him with punishment for trying to turn aside "what had to be." Similarly, before the battle of Plataea, Mardonius appears to have a choice: he may have urged his officers to attack, following the Persian nomos, but he had the option of yielding to the counsel of Artabazus and the Thebans, and withdrawing to Thebes, a plan that seemed more sensible to Herodotus. Yet Mardonius too was moving toward a predestined end. He was to render dike for the murder of Leonidas, as the oracle had predicted.

We need not expect from Herodotus any solution to the dilemma of predestination and free will. They exist in uneasy partnership throughout the classical world and the problem passes into Christian theology unresolved. But here we are looking at the narrower question of why Xerxes' freedom to choose between an imperialist policy and a nonaggressive one was so restricted. If Dionysius of Phocaea, Miltiades, and Themistocles could all propose free choices, why should Xerxes have been deprived of one before he took the fateful step of invading Greece? For though he was not left absolutely without choice, the apparition made it clear that the penalty attached to countermanding the expedition was such that no Persian could endure it and survive.

We may find part of the answer in Sophocles. The what extent were Oedipus and Antigone free agents? They made free choices, but when the pattern of events was finally revealed, their choices appear to have directed them to an end that was determined before they were born. They were unwittingly working out the ancient curse of the Labdacids. In the case of Xerxes, it was not an ancient curse that directed his decisions; instead, he was governed by a choice that Cyrus had put to the Persians before he was born. The Persians had elected the nomos of imperialism when they chose for themselves the life of masters rather than subjects, and the choice that they had made freely under Cyrus so restricted the options of Xerxes four generations later that, for practical purposes, he had to invade Greece. The alternative involved penalties that he could not contemplate.

Xerxes was not the only player in the Histories who was governed by an ancient choice. Lycurgus chose laws for the Spartans, and as Demaratus was to tell Xerxes, their law ruled them as firmly as the Persian king ruled his subjects. The Medes, gathered in an assembly, chose Deioces as king; thereafter they were constrained by their choice and lived under a monarchy with all its trappings. Gyges chose to kill Candaules, and Croesus' fate was governed by that ancient choice made five generations before his time.

The Persians had chosen the nomos of imperialism under Cyrus, and by the time of Xerxes it had attained the status of ancestral law. Time had increased its insistence on obedience. Cyrus attacked the Massagetae because he set his heart on conquering them. Darius invaded Scythia because Asia was overflowing with population and wealth. Both kings conformed to policies that were in line with the nomos of imperialism, and hence no conflict arose. Yet there is no hint that they acted under compulsion. But Xerxes wavered between what Thucydides might have called apragmosyne and polypragmosyne, and discovered that there was a penalty he must pay if he transgressed this nomos. He was in the grip of a dark, ambivalent force that was driving him on to overstep the natural boundaries of his empire, and that force obtained its power from a free choice which the Persians had made long before Xerxes was born: their decision to be rulers rather than subjects, and to possess the good things of an imperial people rather than the toil and sweat of servitude. It was a choice with consequences quite as much as the choice that Agamemnon made at the bay of Aulis, and they reach their consummation with Xerxes. Cyrus might have restrained his hunger for more subjects before he attacked the Massagetae, and Darius might perhaps have held back before he invaded Scythia, but under Xerxes the empire was at such a pitch of wealth and extent that obedience to the nomos of expansionism had to take him beyond the natural boundaries of Asia.

THE IMPERIALIST IMPULSE

During the years that Herodotus researched his Histories, the Persian Empire, grown soft and luxurious, was in decline and another empire, that of Athens (which, like Persia, exacted tribute), had come to dominate the Aegean world, and showed the same restless ambition that marked the Persians under Cyrus. It was a remarkable peripeteia, which seemed to corroborate Herodotus' dictum that in the course of time, great cities became small and small ones became great, and good fortune is forever inconstant. Persian expansionism seemed to have ceased. It was time to ask what had been the nature of the impulse behind it?

Joseph Schumpeter once remarked that the Hellenic world found the reason for Xerxes' campaign utterly baffling. Schumpeter himself explained Persian expansionism as the manifestation of a warrior nation's essence: the Persians had acquired a warlike disposition, and the social organization that went along with it, before their energies could be absorbed by the peaceful exploitation of the land they had settled. They undertook conquest as a manifestation of their ethos, and they introduced imperialism into the Greek world, although Herodotus thought that Croesus had taken the first step. Before the Persian Wars, warfare had been a common state of affairs in Greece; but wars to acquire empires were not—not even the Trojan War, which was a constant comparison. Achaemenid Persia's effort to make Greece a tribute-paying province was the first attempt at empire in the Greek experience, and after Persia, Athens had taken up her legacy.

The conventional wisdom in the Greek world judged the causes of war in terms of provocation, guilt, and vengeance, and behind them all, the working of fate. Herodotus, who had an audience to consider (unlike Thucydides), chose not to ignore conventional wisdom. Thucydides may have been cranky and unjust to refer to the Histories as a prize essay designed for the taste of the immediate public—almost certainly he had Herodotus in mind—but nonetheless Herodotus knew the sort of reasoning with which his audience was familiar. He knew what they would expect. The search for who or what was to blame for the wars was the stock-in-trade of the logioi: the oral chroniclers whom Herodotus in his proem imagines in a debate on the cause of the Persian War. Aristophanes ridicules their logic, but is nevertheless witness to the popularity of this sort of reasoning: retribution fell upon the aitioi, or at least it should in a just world.

Herodotus puts a modicum of distance between himself and all that sort of speculation; instead, he will proceed dealing equally with cities great and small, for the world was changing ceaselessly. For individual changes there might be individual causes, some of which could entail guilt, and in retrospect, the past might disclose tragic motifs, such as tales of divine jealousy following upon great success, and calamity falling upon the overconfident. Foretime was a vast deposit of tragic themes and motifs for poets to mine. But flux was the underlying condition of mankind. For Herodotus, human fortune was by nature inconstant. But the specific problem for which he sought an answer was: why did the Persians choose to attack Greece? For that, tragic story patterns did not supply an answer.

In the end, his explanation was not far removed from Schumpeter's. Imperialism was a nomos: the word embraces Schumpeter's "disposition," but it meant more than that. It was a law that required obedience. However, the Persians had chosen it freely. Cyrus allowed them to taste both the hardships that subjects endured and the good life of a ruling people, and though ancient imperial conquests were not generally motivated by economic concerns, Herodotus imagined the Persians making their choice out of self-interest, but their decision was taken with deliberate intent and it was binding. It took a tough people of the sort which a hard land produced to acquire and maintain an empire, and yet the luxuries that an empire provided its rulers made them soft and eventually unfitted to rule. There was an internal dynamic to the rise and fall of empires that forced them to conform to the ebb and flow of history.

Under Xerxes, Persian expansion reached its zenith. He had inherited the nomos of imperialism. Chosen freely under Cyrus, it had become an expression of Persian nature by the time Xerxes reached the throne. Xerxes could not transgress it with letting go his power. The apparition that came to him in his dream warned him rightly of the consequences of his refusal to invade Greece: he would lose his throne. The abandonment of imperialism would have meant changing the nature of the Persian Empire, and the king himself could not expect to survive so fundamental an innovation.