Does censorship make sense in a democracy? Athens in the fifth century BC, the cradle of democratic thought, became the intellectual and cultural epicentre of the Greek world. The Funeral Speech delivered by Athens’ leading citizen Pericles in 430 BC, as reported by the historian Thucydides, is a paean of praise to the city’s values, reflecting the way Athenians prided themselves on their democratic institutions and the fostering of intellectual and political freedoms. Foremost among those were principles of free and equal speech – in Greek parrhēsia – the licence to say anything without fear of tyrannical repression – and isēgoria, the democratic privilege of all citizen classes being allowed to speak equally.

These freedoms constituted a notable innovation in the Greek political landscape, introduced after Athens’ democratic constitution was created following the overthrow of the tyrant dynasty that had ruled Athens for more than half a century. In the following 50 years Athens was to become the leader of an empire, promoting and implementing innovations in disciplines ranging from rhetoric, mathematics, philosophy and music, to warfare, architecture and medicine. Despite this intellectual efflorescence, ancient sources report intermittent clashes between free speech and political authority, particularly in relation to religious expression. That authority was wielded both by individuals such as Pericles and by the Athenian people themselves, the dēmos, who voted en masse for laws to be passed, and who supplied the juries for law court trials such as that of Socrates in 399 BC.

Athens’ encouragement of openness and experimentation brought explicit benefits for the city. At the beginning of the Peloponnesian War in 431 BC a Corinthian envoy explained the advantage of Athens’ innovativeness to the Spartan leaders:

‘In politics as in technology (tekhnē) the latest ideas must always prevail over the old. Established traditions may be best in a settled society, but when rapid change demands a response there should also be innovative thinking. This is the experience of the Athenians, and the reason their systems have undergone more reform than yours.’

Despite this rapid change, Athens was not immune to censorship and attempts at repression when philosophical or rhetorical ideas threatened the stability of the state, or when public opinion offended powerful individuals. Athens had welcomed non-Athenian thinkers, such as Protagoras from Abdera in northern Greece and the Ionian Anaxagoras, one of Pericles’ close advisers and friends, as well as other so-called sophists, itinerant teachers mainly from outside the city. Episodes of alleged censorship in the period involved both these major intellectual figures.

Anaxagoras was one of the first philosophers to introduce rational explanations for natural phenomena: he claimed that the sun was a fiery rock (he estimated it to be the size of the Peloponnese) and that the moon’s light was a reflection of the sun’s. Such assertions ran counter to traditional religious beliefs, which held celestial bodies to be divine beings (sun and moon were worshipped as Helios and Selene). Religion in fifth-century Athens played a fundamental role in public life, so perceived challenges to the divine order were viewed by an overwhelmingly traditionalistic demos as a potential danger to Athens and an attack on the city’s moral and political structures. ‘We do not intellectualise about the gods’, warns the prophet Teiresias in Euripides’ tragedy (written c. 408 BC), the Bacchae.

Anaxagoras’s rationalist cosmology was said to have led to the accusation of impiety (asebeia), a charge used to target those whose ideas were felt to threaten the religious and civic order. The philosopher was allegedly put on trial for his doctrines during the height of Pericles’ influence in Athenian political life. Since Anaxagoras was close to Pericles as his friend and adviser, the charges may mask political feuding between the populist Pericles and embittered right-wing rivals; but we are told that the Athenian demos was persuaded that the philosopher was a real and present danger, and voted to expel him from Athens.

Protagoras, a prominent sophist and contemporary of Anaxagoras, was author of the famous assertion ‘Man is the measure of all things’. One of his books also began: ‘Concerning the gods, I have no means of knowing whether they exist or not.’ His relativism and religious agnosticism posed a challenge to traditional Athenian values. According to later accounts Protagoras’ teachings were banned (probably in the 440s) and his books were publicly burned in the Athenian agora. The account may be a later misapprehension: among other things, books at this time were a rare commodity, and were not influential in shaping public opinion. The idea that Protagoras was exiled from Athens is also suspect, since Plato’s dialogue Protagoras presents him as an important and respected thinker who remained in Athens until his death. The reports indicate, however, that a historical memory of public unease about Protagoras’ doctrines lingered, and that an official response that included imposing censorship and even burning books did not seem out of the question.

The political and social pressures on free expression in Athens during the period are more clearly illustrated in the case of Pericles’ passing a law against slander to protect himself and his wife Aspasia. Aspasia, a foreign-born woman from Miletus in Asia Minor, became the beloved companion of Pericles from around 445 BC until his death in 429. Depicted in Plato’s dialogue Menexenus as a skilled rhetorician and teacher of both Pericles and Socrates, she was undoubtedly an unusually capable intellectual. Her relationship with Pericles and her supposed influence on his decisions in peace and war made her a target of continuing public slander and political attacks. Comic poets, who wielded considerable influence in shaping public opinion, lampooned Pericles, his policies, and his personal relationships. In some plays Aspasia was presented as running a brothel and using Athenian women as sex-workers for Pericles’ gratification. This was clearly ‘fake news’, but it will have been widely believed at the time (surprisingly, it has often been taken at face value by modern historians).

Pericles’ response, some time in the 430s BC, was to propose a law aimed at preventing comic poets from slandering living individuals. Given the timing, this initiative can be connected to the severe criticism Pericles himself faced following controversial military actions on Samos in 440-439 BC, in which he committed sacrilege in the treatment of his enemies. The instigation of that conflict was popularly blamed on Aspasia, whose home-city Miletus was a military and commercial rival of Samos. The law introduced by Pericles (and passed by public vote) aimed to curb public critiques by comic playwrights, and it represents one of the few recorded instances of explicit legal censorship in Athens. It was short-lived: its repeal (again by public vote) a few years later suggests that any attempt to suppress comic criticism was destined to be ineffective: comedy was after all a genre that specialised in making fun of politicians, both living and dead.

The episode leaves a curious echo in Pericles’ Funeral Speech, which, allegedly, Aspasia helped him to compose. There he urges that the women of Athens who have lost husbands in time of war are ‘best not spoken of, whether for praise or for censure’. Since it is not clear how blame might be attached to war widows, it may be that it hints at the way that Aspasia still came in for censure, not least for allegedly driving Pericles to initiate the Peloponnesian War supposedly because (as the comic poet Aristophanes depicted it) allies of Sparta had abducted two of her sex-workers! Pericles’ censorship law suggests the possibility that in democratic Athens, even as the city prided itself on maintaining its open, deliberative culture, tensions between political power and free expression could arise.

Athens was not always a democracy: in 404 BC the city was defeated, and the victorious Spartans imposed a puppet government, the so-called Thirty Tyrants. Led by the aristocrat Critias, a former associate of Socrates, the junta sought to control the political and intellectual life of Athens. Critias specifically targeted Socrates, requiring that he stop instructing young men in ‘the art of speaking’. For a regime concerned with maintaining its authority, rhetoric – the art of persuasive speech – could indeed have been a powerful tool for destabilising their legitimacy; and Socrates’ method of questioning authority and encouraging critical thought among those he taught might have been felt as particularly dangerous by the Thirty.

The fact that Socrates avoided death at the hands of the Thirty did him no favours when the regime was shortly afterwards overthrown and the democratic constitution restored in 403 BC. In 399, Socrates was brought to trial by democratic accusers on ostensibly moral and religious charges – corrupting young men, failing to honour the city’s gods, and introducing new kinds of gods. Socrates’ association with individuals who were linked to the oligarchic regime, including Critias and Alcibiades, positioned him as an opponent of democracy, a charge he was at pains to refute. But in a society that placed importance on maintaining civic order through religious observance, Socrates’ insistent questioning was perceived as subversive. He was found guilty by a majority of the jury of 500 and sentenced to death by drinking hemlock.

Socrates may have been a convenient scapegoat for a society that had been recently racked by deadly civil strife. But his trial, and the other cases of censorship in Athens, reflect an enduring anxiety about the power of speech, whether used for good ends or bad. Speech in these instances was seen not just as a form of personal expression, but as a force capable of shaping minds, challenging authority, and destabilising the state. The very ideas that have come to symbolise intellectual freedom today – critical inquiry, the questioning of power, and the pursuit of philosophical truth – were seen as threats to be neutralised in the name of public safety or political expediency.

These historical episodes confront us with the question: is the suppression of ideas ever justifiable for the survival of a society? Did Athenian attempts at censorship betray the principles of parrhēsia and isēgoria it claimed to uphold? The Athenian experience reminds us that censorship is often a tool wielded not just by tyrants, but also by democracies when they feel threatened. Societies that value freedom must grapple constantly with the uncomfortable reality that open discourse can lead to dissent, disruption, and the widespread belief in falsehoods. The alternative – a society in which speech is curtailed in the name of stability and truthfulness – comes at a potentially greater cost. It silences the voices that push societies forward, that challenge established norms, and that serve to expand our understanding of truth, justice, and human welfare.