The Case for Debate

Every free society since Athens has decided its most important questions by argument: whether to go to war, whom to punish, which laws to live under. Debate is a form of inquiry that lets a polity find the truth and make those decisions informed. To keep the practice alive, it needs interlocutors who can argue well and a people honest enough to listen to both sides.

In 508 BC, the Athenian statesman Cleisthenes reorganized the citizens of Athens into ten tribes so that more of them would take part in governing the city.¹ The historian Herodotus called what followed isegoria, an equal right of speech, and credited it with the city’s strength in war: once rid of its tyrants, Athens became “by far the best of all.”² Each assembly opened with a herald asking who wished to address it, first among the men over fifty and then among every other citizen.³ The playwright Euripides had Athens’s legendary king name that question as the mark of a free city: “Who hath wholesome counsel to declare unto the state?”⁴

But a city that decides by argument is limited by how well it argues.

Debate is the means by which we search for truth. Each side presents its strongest case and refutes the other’s, so the people deciding hear both before they act.

Protagoras of Abdera, a teacher who spent most of his life at Athens, was by the biographer Diogenes Laertius’s account the first “to maintain that there are two sides to every question, opposed to each other,” and the first to hold contests in debating.⁵ In the funeral oration Thucydides gives to the Athenian statesman Pericles in 431 BC, Athens treats discussion as “an indispensable preliminary to any wise action at all” and holds that its ordinary citizens can judge public matters fairly.⁶ Aristotle later took the same practice inside a single mind: arguing both sides of a question, he wrote, lets a thinker detect the truth and the error in each more easily.⁷ A decision made after two sides have argued has been checked at its weakest points by the people most motivated to find them.

A speaker practices debate as inquiry only when he has good character and makes arguments that any listener can understand. Persuasion is a tool that can be used for good and evil, which is why the Roman teacher Quintilian, quoting the statesman Cato, required the orator to be “a good man, skilled in speaking”: without goodness, eloquence forges weapons “not for a soldier, but for a robber.”⁸ A speaker must have character that puts the truth ahead of winning. Decades before his trial in 399 BC, Socrates questioned any Athenian who claimed to be wise, and young men of the richer classes followed him; in his words, they “often imitate me, and examine others themselves.”⁹ He told the rhetorician Gorgias he was glad to be refuted whenever he said something untrue, since being refuted was the greater gain.¹⁰ At his trial he called the unexamined life “not worth living.”⁹ A speaker has to be persuadable to be persuasive. If he only asserts his case, he merely identifies the people who already agree with him.

Character asks a debater to argue exhaustively for the truth, on whichever side he is assigned. He may argue a side he would not have chosen, but he does not lie for it. Sound reasoning gives the listener grounds that he can verify. Where those grounds run out, the listener has to trust the speaker. Debates turn on questions where, as Aristotle wrote, “exact certainty is impossible and opinions are divided,” and on those questions people “believe good men more fully and more readily than others.”¹¹ Aristotle called these two proofs logos and ethos. Character also governs how a debater treats the other side. The debater should treat his opponent and his audience as intelligent people who matter. The philosopher John Stuart Mill counted it among the gravest offences in public discussion “to misstate the elements of the case, or misrepresent the opposite opinion.”¹²

A speaker of good character must also be understood. Correctness doesn’t guarantee persuasion. An idea has no voice of its own. It must be argued, and argued poorly, it loses. Aristotle held that true and just things “have a natural tendency to prevail over their opposites,” so that when judges decide wrongly “the defeat must be due to the speakers themselves.”¹³ The most basic way a speaker fails is an argument the judges cannot follow. People believe what they can understand, so clarity comes before persuasion. No one can be convinced by an argument they do not understand. For the same reason, Aristotle told speakers to meet people on the ground of their own convictions.⁷

A debater should not limit themselves to only one format. Habits built for one format only work inside the format they were made for. A debater who relies on them can win a round and still be unable to make the same case in conversation, in a speech, or anywhere else that requires communication. An argument that transcends the format has to be accessible to any listener, which takes two more of the classical disciplines. Aristotle held that a speaker must also put his hearers “into the right frame of mind,” which means speaking to what the listener already knows and cares about.¹¹ The rhetorician Isocrates, who founded a school of rhetoric in Athens, wrote against the sophists of his own day that a speech is good only if it has “fitness for the occasion,” what the Greeks called kairos.¹⁴ The best debaters are good at many formats because they build each argument from what any listener can follow. A student who learns that can argue as well in front of a jury or a board as in front of a judge.

Debate and its counterfeit were born together, in the same city and sometimes in the same teacher.

Protagoras sold the training to the sons of the rich, taught them “the tricks of their trade,” and charged a hundred minae, about ten thousand days of a builder’s pay.¹⁵ In 427 BC the Sicilian city of Leontini sent the rhetorician Gorgias to ask Athens for help against Syracuse.¹⁶ His antitheses and balanced clauses were new to the assembly, and by the historian Diodorus’s account the Athenians heard them with wonder and voted the alliance.¹⁶ Four years later the comic poet Aristophanes put the trade on stage in Clouds, with Socrates as its master and a school that teaches “two courses of reasoning, the true and the false.”¹⁷ In Plato’s dialogue named for him, Gorgias conceded that his persuasion produced belief about the just and the unjust and taught neither.¹⁸ Aristotle judged the training Protagoras sold a fraud.¹⁹

The ancient Greeks called these teachers sophists, and their practice sophistry. A sophist reasons with clever but fallacious arguments to make people believe something for a purpose outside the truth. Aristotle defined the sophist’s art as “the semblance of wisdom without the reality.”²⁰

A speaker can master reasoning, credibility, the listener’s frame of mind and the moment, and still be a sophist. The sophists had all of those tools. Without a moral foundation to guide him, a speaker finds it easy to authorize himself to use them to make a weak argument look strong, whether or not it is true.

A good argument still needs listeners who want the truth. In the summer of 428 BC, Mytilene, a city on the island of Lesbos, renounced its alliance with Athens and appealed to Sparta for aid. Athens, at war with Sparta since 431 BC, besieged the city and forced its surrender. “In the fury of the moment” the citizens’ assembly adopted a motion by Cleon, then the most powerful speaker in Athens: death for every grown man in the city and slavery for the women and children. One citizen, Diodotus, argued against the decree and lost. A galley sailed for Lesbos with the order to carry it out without delay.²¹

By the next morning most Athenians wanted to reconsider, so an assembly was called at once. Diodotus argued that the common people of Mytilene had taken no part in the revolt and had surrendered the city themselves. His motion carried by a show of hands that was nearly even. A second galley set out a day and a night behind the first and reached Mytilene as the Athenian commander “had only just had time to read the decree, and to prepare to execute the sentence.”²¹

When the position is the morally correct one, failing to persuade has real stakes.

Diodotus had such listeners on the second day and asked them to decide on the argument alone: a good citizen, he said, should win “by beating them fairly in argument,” never by frightening his opponents.²¹ Socrates faced the same city with an audience that did not care for the truth.

In 399 BC, twenty-eight years after the second galley reached Mytilene, Athens put Socrates on trial. He was past seventy and had never stood in a court before. Three men brought the charge, each with a quarrel from his own trade: Meletus for the poets, Anytus for the craftsmen, Lycon for the rhetoricians. They accused him of denying the gods of the city and corrupting the young.²² That charge was the newer of two. The older one had no accuser he could answer. It came from Clouds, the comedy Aristophanes had staged in 423, which showed Socrates as a man who taught how to make the weaker argument beat the stronger. Most of the jurors had been children then and had grown up believing it.²² Socrates told them that this rumor was the more dangerous accuser, because a rumor cannot be called to the stand and questioned.²² The jury had made up its mind before he spoke.

The accusers opened by warning the jury not to be taken in by his eloquence, so that anything he said well would count against him. Socrates answered that they had “hardly spoken a word of truth,” and that he would accept the name of eloquent only if eloquence meant “the force of truth.”²³ In other words, for Socrates, eloquence was meaningless apart from truth.²² The law gave the case a single day.²⁴ At its end the jury found him guilty, by a count that surprised him: “I had thought that the majority against me would have been far larger; but now, had thirty votes gone over to the other side, I should have been acquitted.”²⁵ The penalty came next, in a second vote. Meletus asked for death, but Socrates was entitled to propose a lesser penalty and offered a fine of one mina, which his friends raised to thirty. Between a fine of thirty minae and death, the jury voted for death.²⁵

Athens had now cast two near-even votes on the lives of people who had done no wrong: the commons of Mytilene, who in Diodotus’s words “had nothing to do with the revolt,” and a man who told the jury he had wronged no one.²⁶ The difference between the two verdicts was time. Mytilene got a second day. Socrates asked the jury for one and told them that with more days he believed he would have convinced them, but the law allowed none.²⁷ He said afterward that he had not lost for want of words: the jury had wanted him to plead “weeping and wailing and lamenting,” which he had refused to do.²⁸ Diodotus won by refusing to frighten his audience. Socrates lost by refusing to flatter his.²⁸ The city regretted its vote by the next morning. Athens came to regret the second one as well, according to a tradition written down centuries later.²⁹

Debate cannot protect the truth in a room that has already made up its mind.

The second galley reached Mytilene as the Athenian commander had only just read the decree, so the massacre was prevented.²¹ It was not a full reprieve: on Cleon’s motion, “rather more than a thousand” of the men sent to Athens as leaders of the revolt were put to death.²¹ The second debate decided the difference between a city and a thousand men.

The same stakes hold now. American public life is losing much of what a round teaches, starting with patience for the people on the other side. In 2016, 47 percent of Republicans and 35 percent of Democrats told Pew Research Center that members of the other party were more immoral than other Americans. By 2022, 72 percent of Republicans and 63 percent of Democrats said so.³⁰ Majorities in both parties called the other side more closed-minded, 83 percent of Democrats and 69 percent of Republicans.³⁰

Seeing opponents as immoral makes violence against them easier to justify. In 2021, 15 percent of Americans told PRRI that “because things have gotten so far off track, true American patriots may have to resort to violence in order to save our country.” By 2023, 23 percent agreed.³¹ Stanford psychologist Albert Bandura explained how the one leads to the other. People find it “difficult to mistreat humanized persons without suffering personal distress and self-condemnation,” he wrote, but “self-censure for cruel conduct can be disengaged by stripping people of human qualities.”³² Where that is not enough, the same restraint “can be eliminated by attributing demonic or bestial qualities” to them.³² When discussion and civil dialogue are lost, people give themselves permission to demonize the other side and to authorize violence against it.

Before contempt reaches violence, it usually passes through silence, since an opponent stripped of human qualities no longer seems to deserve a hearing. Two justices traced where that leads nearly a century ago. Justice Louis Brandeis, who modeled one sentence of his concurring opinion in Whitney v. California on Pericles’s funeral oration, wrote there that the founders knew “that fear breeds repression; that repression breeds hate; that hate menaces stable government; that the path of safety lies in the opportunity to discuss freely supposed grievances and proposed remedies.”³³ Sixteen years later, in West Virginia State Board of Education v. Barnette, Justice Robert Jackson warned that “those who begin coercive elimination of dissent soon find themselves exterminating dissenters.”³⁴ Justice Brandeis named the remedy: “more speech, not enforced silence.”³³

Above all, a free people has to be willing to talk with the people it disagrees with.