Did Thucydides Accurately Report the Mytilene Debate?
Thucydides’ Mytilene debate underscores his broader reliability rather than undermines it.
One of the oldest and most important questions about Thucydides’ History of the Peloponnesian War concerns the speeches he includes—did he reproduce what was actually said as closely as possible, or did he feel free to invent arguments and even entire orations? Scholars have long debated this, yet no consensus has emerged. The answer shapes how we interpret both Thucydides’ method and the reliability of his account.
Thucydides himself explicitly addresses this issue in Book I, chapter 22, where he explains how he handles the words delivered by major figures in assemblies and negotiations. But interpretations of this passage vary widely. Some read it to mean Thucydides scrupulously set down the arguments and overall sense of each speech as best he could remember (or find out). Others assert that he composed them more freely to serve the dramatic or thematic purpose of his narrative, sometimes even inventing entire speeches that were never delivered as such.
This debate has not been purely abstract. The positions scholars take directly influence how they treat critical passages—foremost among them the Mytilene debate of Book III, where the Athenians must decide how to punish the city of Mytilene after it revolts. If Thucydides wrote his speeches in near-invented form, the stirring exchange between the demagogue Cleon and the more moderate Diodotus is more a window into Thucydides’ personal reflections than evidence of what was actually said. If instead he truly strove to capture the substance and style of real orations, the Mytilene debate becomes a historical record of an actual clash in the Athenian assembly.
Below, we explore Thucydides’ statement in Book I, the longstanding criticisms of it, and how the Mytilene debate itself clarifies (rather than undermines) his declared method. In the end, we see strong reasons to believe Thucydides did attempt to report actual speeches accurately—at least in what he took to be their essential arguments and thrust.
Thucydides’ Method in Book I, Chapter 22
Thucydides famously writes that capturing exact words is “difficult,” both for him and his sources, so he uses his judgment in reconstructing the sense of what each speaker argued. This is the passage often paraphrased as: he recorded the speeches “as closely as possible to the overall meaning of what was truly said.” The key phrase is sometimes translated “the general sense” or “the overall argument.” Some readers have emphasized that Thucydides claims a measure of creativity (where he says he has reconstructed what each speaker “would most appropriately have said on those occasions”). Others highlight that he also promises closeness to what was actually spoken—pointing out he is trying to be accurate, not merely imaginative.
Skeptics such as Eduard Schwartz tried to nullify the explicit claim of accuracy. They argued that Thucydides was more interested in the “intentions” or “practical purpose” behind each oration than in the literal content. Yet many have observed that such a stance essentially erodes Thucydides’ own words, which consistently emphasize that he was recording real speeches or, at minimum, close approximations. Schwartz and others even declared certain speeches (for instance, the Athenian address at Sparta in Book I) to be outright fictions, contrary to Thucydides’ statement that these envoys truly spoke.
A crucial counterargument came from A. W. Gomme, who maintained that Thucydides’ text in I. 22 should be taken at face value. Gomme systematically dismantled the idea that Thucydides engaged in open invention. He instead emphasized that Thucydides was fully capable of shaping, editing, and giving rhetorical form to real arguments without abandoning the fact that these speeches were truly delivered. Gomme’s central point—still highly relevant—was that ignoring Thucydides’ own claim to authenticity (and calling entire orations mere creative writing) undermines the historian’s general credibility. Thucydides’ insistence on excluding “the fabulous element” would become empty if he populated his history with speeches that never happened.
Others concede that maybe Thucydides began with close fidelity but changed his mind midway through the writing process. They try to explain perceived discrepancies by positing “earlier” and “later” strata of composition. According to this notion, he might have intended accurate reproduction in the early books, but, as time went on, he allegedly allowed himself more imaginative latitude. Yet no strong evidence supports this. Book I appears carefully polished, so it hardly looks like a primitive draft he would have revised out of all recognition. Moreover, Thucydides provides no notice he is abandoning his principle of accuracy for a freer approach. If we took that seriously, we would have to call his reliability into question generally.
So if we trust the straightforward reading—that Thucydides in fact tried to record actual speeches as well as he could—how do we square that with the obvious artistry in the text? The speeches do often present sweeping generalizations about politics, human nature, and empire. They shape the structure of the History, setting out philosophical arguments or moral dilemmas in a way that seems more cohesive than random. But, as many historians note, real politicians do sometimes rise to broad reflections, especially in a major crisis. Thucydides may well have selected which speeches to include out of many that were delivered. He also compressed or paraphrased them, thus giving them a conceptual unity, but that would not mean he invented them wholesale.
Sophie
The Mytilene Debate in Historical Context
The Mytilene debate, in Book III (36–50), provides a revealing test case. Thucydides tells how, in 427 BCE, Athens faced a dangerous situation: Mytilene, on the island of Lesbos, had revolted, despite enjoying a privileged alliance status. The Athenians were enraged. They had expected to be secure behind their walls and navy, believing the war would end quickly. Yet by 427, money was running short, a destructive plague had raged, and the Spartans had just sent a fleet into the Aegean, nearly inspiring further revolts. The fall of Mytilene back under Athenian control might have felt like a near-miracle, and the Athenians—suffering fear and fury—voted initially to punish the city harshly.
At a first meeting of the assembly, Cleon son of Cleaenetus proposed executing all the adult male citizens of Mytilene and enslaving the women and children. His motion prevailed. But overnight, second thoughts prompted a new assembly the next morning, at which the Athenians reconsidered. Thucydides recounts the second meeting in direct discourse, framing it as a debate between two main orators: Cleon (again) and Diodotus, who opposed the mass execution. The tension is extreme: a first trireme had already sailed to Mytilene with instructions to begin the slaughter. If the assembly reversed that decision, a second trireme must depart immediately to overtake the first.
Thucydides describes Cleon as “the most violent of the citizens,” newly powerful with the people. Cleon’s main argument: justice and necessity demanded punishing Mytilene to deter all future revolts. The notion of differentiating oligarchs from the general populace was impossible—everyone participated in the rebellion, and leniency would only breed more defiance. Implicitly, Cleon also attacks the mild, Periclean approach to empire that had allowed Mytilene’s privileged status. He rails against pity, mercy, and the Athenian love of “fine speeches”—accusing the demos of gullibility and weakness.
Diodotus, the principal opponent, avoids sentiment. Rather than appealing directly to compassion, he insists that executing the entire population is unwise from the standpoint of Athenian self-interest. Terror seldom works as a deterrent: prospective rebels hope to succeed, and if they know that surrender means a guaranteed massacre, they have every reason to fight to the last. Far better, says Diodotus, is a more measured response—punishing the actual instigators but preserving the general population, so that future rebels will at least hope they can negotiate a surrender and survive. Diodotus thus defends the traditional Periclean line: do not provoke the demos in other cities into total hostility. Keep them from uniting behind oligarchs by offering the possibility of “mild” terms if they capitulate early.
So the arguments clash, both claiming to serve Athenian interests. Finally, Diodotus narrowly wins the vote. A second trireme rushes off to Mytilene—arriving just in time to forestall mass killings. However, more than a thousand alleged ring-leaders are ultimately singled out and executed on Cleon’s motion, presumably without further debate. While no complete exoneration of Mytilene, it avoids exterminating the entire citizen body.
Sophie
Authentic or Invented? Why the Debate Fits the Historical Reality
The Mytilene debate has often provoked skepticism because it feels extremely dramatic and includes broad reflections on human nature, deterrence, and empire. Critics ask whether an Athenian assembly could be swayed by such “abstract” arguments. Moreover, Cleon’s harsh rhetoric—condemning democracy as unsuited to empire—strikes some as extreme, as though it might be Thucydides editorializing.
Yet these concerns fade when we recall the actual context of 427. The Athenians were desperate after setbacks. The plague had eroded morale. Many might welcome a drastic measure against Mytilene, while others might be horrified by the idea of executing thousands of fellow Greeks. That very tension sets the stage for an impassioned debate, replete with anger, fear, and theoretical arguments. It is quite plausible that Cleon—known for aggression—openly indicted the Athenian demos for softness or rhetorical self-indulgence. We have no ground to say it was “too extreme” or “too philosophical” to be real. Emotions ran high, and the stakes were existential.
Similarly, Diodotus’ argument from expedience, rather than moral pity, makes perfect sense in context. The prior day’s discussion likely brought out pleas for mercy. Cleon had clearly preempted them by insisting that an appeal to humaneness was naive or borderline treacherous. Diodotus, forced to craft a position that might persuade a fearful, angry audience, avoids praising compassion and frames the milder course in hard strategic terms. There is strong internal logic here for a real public debate. Indeed, historians note that Mytilene’s position as an “ally” with semi-autonomy must have been a flashpoint—some Athenians favored standardizing the empire, forcing all states into direct tribute-paying subjection. Others thought preserving the existing arrangement with only partial interference had worked well enough. Cleon represents the break from moderate policy; Diodotus stands for continuity of Periclean traditions.
Also worth noting: Thucydides references how close the final vote was, and how it occasioned an immediate dispatch of a second trireme—details that ring distinctly historical, rather than invented for rhetorical neatness. The last-minute rescue is a dramatic flourish, yes, but it is also plausible. The Mytilenean debate itself, then, shows every sign of being an authentic reflection of actual arguments, shaped by Thucydides’ editorial compression and style. The substance of the speeches is consistent with the bigger strategic divides in Athens.
Thucydides’ Larger Artistic Vision: Selection, Not Fabrication
The Mytilene debate also illuminates Thucydides’ literary artistry. Clearly, he included only two speeches. In reality, multiple orators spoke across two assembly meetings. We see, for example, that prior arguments about guilt and innocence—whether the Mytilenean demos was forced into rebellion—surfaced before Diodotus and Cleon gave their final addresses. Yet Thucydides arranges the scene to highlight the most extreme clash: a policy of terror (Cleon) versus a policy of calculated leniency (Diodotus). These positions dramatize Athens’ internal dilemma and stand in for broader approaches to empire.
Such editorial shaping does not require the speeches to be fictional; it simply explains why Thucydides selected them. In other words, the “art” lies in deciding which speeches to record in detail, not in concocting them from scratch. Thucydides might have transcribed them soon after, or gleaned them from eyewitnesses—he was probably in Athens at the time. He compressed them (real political speeches would take far longer). The orators might well have diverged in tone or content more than we see, but we can assume Thucydides faithfully captured their essence and principal lines of reasoning.
Moreover, the Mytilene debate exemplifies how a single crisis can lay bare fundamental questions of rule, punishment, deterrence, and the ethical dimension of empire. Thucydides, as a historian with philosophical inclinations, used it to illustrate how Athens struggled between humane or prudent moderation and harsh, fear-based control—an issue resonating throughout the war. He might have refined, reorganized, or slightly recast words for clarity, but the main ideas presumably come from actual arguments made on the assembly floor.
Conclusion: The Mytilene Debate as a Real Exchange
The speeches at Mytilene are consistent with Thucydides’ declared objective in Book I: to convey the core arguments really used by historical figures, shaped by his own editorial judgment and memory. While some scholars suspect invention because of the elevated rhetoric or how neatly each viewpoint is laid out, a closer look at the historical moment reveals that such powerful, wide-ranging arguments were plausible, even likely. Athenian assemblies could indeed reward (or at least allow) articulate oratory with references to deeper truths about human nature, justice, and expediency. Cleon’s attacks on rhetorical indulgence and pity, along with Diodotus’ pragmatic appeal to Athenian self-interest, reflect genuine possibilities in a crisis overshadowed by fear and fury.
Thus, Thucydides’ Mytilene debate underscores his broader reliability rather than undermines it. We see no compelling evidence that he invented entire speeches. Instead, the artistry of the History lies in Thucydides’ method of selecting and shaping what he found important: the rhetorical and philosophical heart of these assemblies. He used them to expose a real fissure in Athenian policy—and, more widely, an enduring tension in imperial rule between benevolent moderation and the logic of terror. His account remains a masterpiece of historical reporting that artfully arranges genuine events and speeches.
If we accept Thucydides’ statement in Book I, chapter 22, at face value—and if the Mytilene debate indeed matches the historical context—then we can read his entire work confident that he aimed for accuracy in reporting what was truly said. He chose particular orations that vividly illustrate the moral, strategic, and emotional conflicts at play. On that basis, the Mytilene debate stands as one of the History’s finest examples of Thucydides’ fusion of historical detail, political insight, and literary craft—yet without requiring him to invent arguments wholesale or contradict his strict promise of truthfulness.
