The Sophists

Born in Abdera in Thrace (the same city that produced Democritus, who was a generation younger), Protagoras was by ancient consensus the first and greatest of the Sophists. Plato has Protagoras say of himself: 'I admit that I am a sophist and that I educate people' (Protagoras 317b) — a frank avowal of an identity others tried to conceal. He spent much of his career in Athens, where he was closely associated with Pericles, who commissioned him to draft the constitution for the Panhellenic colony of Thurii in southern Italy (444/443 BCE). He was reportedly the first to charge fees for instruction — enormous sums by some accounts, though Protagoras himself offered a remarkable alternative: the student could, upon completing the course, go to a temple, swear an oath as to how much the teaching was worth, and pay that amount instead.

His most famous doctrine is the 'man-measure' thesis, preserved as the opening sentence of his work Truth (also called Refutations or Throwing Arguments): 'Of all things the measure is man, of things that are that they are, and of things that are not that they are not' (DK 80 B1). The meaning is intensely debated. On the individualist reading (favoured by Plato in the Theaetetus, 152a), each person's perceptions constitute truth for that person — the wind is cold for me if I feel it as cold, warm for you if you feel it as warm, and there is no further fact of the matter. On a minority communal reading defended by some modern scholars, 'man' means the human species or the community — things are as they appear to human beings collectively, not as they might appear to gods, animals, or abstract reason. Either way, the thesis eliminates any appeal to a mind-independent reality that could adjudicate between competing appearances.

Plato's Protagoras (320c–328d) presents Protagoras delivering a 'Great Speech' — partly myth, partly argument — defending the claim that virtue (aretē) can be taught. The myth tells how Zeus distributed justice (dikē) and shame (aidōs) to all humans equally, unlike the specialized crafts which are distributed to a few; this is why every citizen has a right to speak on political matters and why political virtue, unlike shoemaking or medicine, is everyone's business. The argument that follows emphasizes that societies punish wrongdoing not for retribution (which would concern the past) but for deterrence and reform (which concern the future) — proof that they implicitly believe virtue is teachable. This is one of the earliest consequentialist theories of punishment.

Protagoras was also famous for the art of antilogic — arguing on both sides of any question. His Antilogiae (Opposing Arguments) reportedly demonstrated that on every issue there are two logoi (arguments) opposed to each other. This does not necessarily imply that both are equally true; it may mean that every position faces genuine objections, and the skilled speaker must understand both sides. The technique was pedagogical: students learned to argue for and against any thesis, developing the intellectual flexibility needed for democratic deliberation.

On religion, Protagoras opened his work On the Gods with a declaration that cost him dearly: 'Concerning the gods I am not in a position to know either that they exist or that they do not exist, or what they are like in form. For there are many obstacles to knowledge: the obscurity of the matter and the brevity of human life' (DK 80 B4). This is not atheism but a principled agnosticism grounded in epistemological humility — the same brevity of life and obscurity of subject matter that limits all human knowledge. Ancient sources report that this declaration led to a prosecution for impiety and that his books were burned in the agora, though the details are variously reported and some scholars doubt the historicity of the trial. He reportedly drowned at sea while fleeing Athens, around 420 BCE.

Born in Leontini in Sicily, Gorgias was reportedly a student of Empedocles and lived to an extraordinary age — ancient sources give figures between 105 and 109 years. He arrived in Athens in 427 BCE as part of an embassy from Leontini seeking military aid against Syracuse, and his rhetorical display on that occasion reportedly electrified the city: Athenians had never heard prose of such power, with its elaborate antitheses, balanced clauses (isokola), rhyming endings (homoioteleuta), and hypnotic rhythms. He stayed to teach, accumulating enormous wealth — enough to dedicate a gold statue of himself at Delphi.

Gorgias's philosophical reputation rests on a lost work known as On Not Being, or On Nature (Peri tou Mē Ontos ē Peri Physeōs) — its title a direct inversion of Parmenides' On Nature. Two paraphrases survive, in Sextus Empiricus (Against the Mathematicians VII.65–87) and in the pseudo-Aristotelian treatise On Melissus, Xenophanes, and Gorgias (MXG). According to later paraphrases (especially Sextus and MXG), the work presents three theses: (1) nothing exists; (2) even if something exists, it cannot be known by humans; (3) even if it can be known, it cannot be communicated to another person. Whether this is serious metaphysical nihilism, an elaborate parody of Eleatic reasoning, a demonstration of rhetorical skill, or an epistemological argument about the limits of language remains one of the most debated questions in the history of philosophy. The third thesis — that communication fails because words and experiences are incommensurable — has attracted particular interest from modern philosophers of language.

The Encomium of Helen survives complete and is Gorgias's masterpiece. It defends Helen of Troy against blame by systematically eliminating the possible causes of her departure: fate and the gods (against which mortals are powerless); physical force (the weak cannot resist the strong); the persuasion of logos (speech); or the power of erōs (love/desire). The argument about logos is the philosophical core: 'Speech is a powerful lord that with the smallest and most invisible body accomplishes the most divine works. It can stop fear and remove grief and instill pleasure and enhance pity' (DK 82 B11.8). Logos works on the soul as drugs work on the body — altering its state without the subject's rational consent. This analogy between rhetoric and pharmacology runs throughout the text and establishes a theory of persuasion as quasi-physical causation.

Gorgias refused to claim that he taught virtue — unlike Protagoras. In Plato's Meno (95c), Gorgias is reported to have laughed at other Sophists for promising to teach aretē; he offered only the ability to speak persuasively. This modesty (or this limitation) made his contribution more focused: not a complete education but a single, devastating skill. His theory centered on kairos — the opportune moment, the right word at the right time — rather than on fixed rules. This made his rhetoric situational, adaptive, and resistant to systematic codification, in contrast to the handbooks (technai) that later proliferated.

His influence was immense. Isocrates, the most successful educator of the fourth century, began as his student. Through Isocrates, Gorgias's model of rhetorical education — centered on prose composition rather than dialectical argument — became the dominant form of higher education in the Hellenistic and Roman worlds, competing with and eventually largely displacing the philosophical model of Plato's Academy. Aristotle's Rhetoric systematically engages with Gorgianic theory. Cicero, Quintilian, and the entire Roman oratorical tradition descend from his innovations.

Born in Chalcedon (modern Kadıköy, on the Asian side of the Bosphorus), Thrasymachus was primarily known in antiquity as a rhetorician and prose stylist rather than a philosopher. He developed innovations in prose rhythm, emotional appeal, and the 'middle style' — a mean between the elevated grandeur of Gorgias and the plain simplicity of Lysias. Aristotle's student Theophrastus credited him with the invention of the 'periodic sentence' (the complex syntactic structure that builds to a climax). Dionysius of Halicarnassus studied his work as a model of forceful expression.

His philosophical fame rests entirely on Book I of Plato's Republic, where he bursts into the conversation with characteristic aggression: 'I say that justice is nothing other than the advantage of the stronger' (Republic 338c). The claim has multiple layers. At the descriptive level, it asserts a sociological fact: in every political system, the ruling group makes laws that serve its own interests and calls obedience to those laws 'justice.' The democratic majority legislates for its advantage and calls that justice; an oligarchy does the same; a tyranny does the same. 'Justice' is simply the name that power gives to its own interest. At the normative level, Thrasymachus may also be arguing that this is how things should be — that the naturally strong have a right to exploit the weak, and that conventional justice is a constraint that benefits only the rulers who impose it.

Socrates presses Thrasymachus through a series of analogies (the doctor, the pilot, the shepherd) to concede that genuine expertise serves the interest of the subject, not the expert — the doctor aims at the patient's health, not the doctor's profit. Thrasymachus's response is revealing: he insists that the 'real' ruler — the ruler qua ruler, in the precise sense — never makes mistakes and always successfully pursues his own advantage. The perfectly unjust man — the successful tyrant — is happier than the just man. Injustice is 'virtue and wisdom'; justice is 'noble simplicity' (Republic 348c–d). Thrasymachus thus combines a cynical sociology of law with an immoralist ethics.

Outside the Republic, we know little of Thrasymachus's views. A fragment from a political speech (DK 85 B1) expresses disillusionment with both oligarchy and democracy and calls for a return to 'the ancestral constitution' (patrios politeia) — a moderate position that sits uneasily with the extremism of his Republic persona. Scholars have debated whether Plato's portrayal captures the historical Thrasymachus's views or transforms a competent rhetorician into a philosophical strawman. The blush that Socrates notes at Republic 350d — Thrasymachus reddens when refuted — may suggest Plato recognized a gap between the man's provocative posture and his actual convictions.

His rhetorical innovations were taken seriously. Cicero (Orator 40) credits him with pioneering the use of rhythmic prose (specifically the paean — a foot of one long and three short syllables — for sentence endings). His ability to arouse and calm emotions at will was proverbial: Plato's Phaedrus (267c–d) reports that Thrasymachus 'was best at making people angry by his speeches, and then soothing them when they were angry' — the oratorical equivalent of the pharmacological power Gorgias attributed to logos.

Hippias of Elis was the great polymath of the sophistic movement — a man who prided himself on knowing and doing everything. Plato devoted two dialogues to him (Hippias Major on the nature of beauty; Hippias Minor on whether voluntary wrongdoing is better than involuntary), and in both, Hippias is presented as boastful but intellectually limited. The portrayal is hostile, but even through Plato's lens the range of Hippias's competence is astonishing.

At the Olympic Games, Hippias appeared wearing nothing he had not made with his own hands: his ring, his oil flask, his strigil, his shoes, his cloak, his tunic, and his belt — each crafted by himself (Plato, Hippias Minor 368b–d). He offered instruction in arithmetic, geometry, astronomy, harmonics, mnemonics, grammar, rhetoric, history, painting, sculpture, and metalwork. He composed tragedies, dithyrambs, epics, and various prose works. He developed a mnemonic system — an art of memory — that reportedly allowed him to repeat fifty names after hearing them once. He compiled the first list of Olympic victors (the Olympionikai), which became a fundamental chronological tool for Greek historians.

Philosophically, Hippias is most significant for the distinction between nature (physis) and convention (nomos) — specifically, for privileging nature over convention. Plato's Protagoras (337c–d) has Hippias declare: 'I regard you all as kinsmen and family and fellow-citizens — by nature, not by convention. For by nature like is akin to like, but convention, which is a tyrant over human beings, forces many things contrary to nature.' This appeal to natural kinship across conventional boundaries — treating all Greeks (and perhaps all humans) as naturally related regardless of political divisions — represents a cosmopolitan position with radical implications. If convention is a 'tyrant' that forces things contrary to nature, then conventional distinctions (between Greek and barbarian, citizen and foreigner, free and slave) lack natural justification.

Hippias also contributed to mathematics. Proclus credits him with the discovery of the quadratrix — a curve that can be used to trisect any angle and to square the circle (though the latter application may be due to Dinostratus, a generation later). If the attribution is correct, this is one of the earliest examples of a transcendental curve in mathematics — a curve that cannot be defined by a polynomial equation — and represents a genuinely original contribution to geometry.

His mnemonic system may have had philosophical implications. If one can master all knowledge through proper technique, then the distinctions between disciplines are less fundamental than they appear — all knowledge is ultimately one, accessible to the trained mind. This encyclopedic ideal — the unity of knowledge — reappears in Aristotle's ambition to map the entire domain of human understanding, and may owe something to Hippias's practical demonstration that a single individual could master the whole range of Greek learning.

Born on the island of Ceos in the Cyclades, Prodicus combined two distinctive intellectual pursuits: an extraordinary precision in distinguishing the meanings of near-synonymous words (what the Greeks called synonymics or the correctness of names), and a naturalistic theory of the origin of religion. He visited Athens repeatedly as an ambassador from Ceos and supplemented his diplomatic income by giving public lectures and private instruction. Socrates reportedly attended his one-drachma lecture (the budget option — the fifty-drachma version was reserved for wealthier students) and occasionally professed to be his student, though with characteristic irony.

Prodicus's synonymics — his insistence on precise verbal distinctions — was famous in antiquity and was treated by both Plato and Aristotle as his signature contribution. He distinguished, for example, between 'desire' and 'longing' and 'erōs'; between 'joy' and 'delight' and 'gladness'; between 'courage' and 'boldness' and 'daring'; between 'being' and 'becoming' and 'existing.' Plato parodies this tendency in several dialogues (Protagoras 337a–c, 340a–b; Laches 197d; Meno 75e; Charmides 163d), having Prodicus interrupt arguments to insist on terminological precision. But the project was philosophically serious: if different words have genuinely different meanings, then conceptual confusion arises from treating synonyms as interchangeable, and philosophical clarity requires scrupulous attention to language. This anticipates the ordinary-language philosophy of the twentieth century and connects to the broader sophistic interest in the 'correctness of names' (orthoepeia).

Prodicus's most celebrated composition was the allegory of the Choice of Heracles, preserved in Xenophon's Memorabilia (II.1.21–34). In this moral fable, the young Heracles sits at a crossroads and is approached by two women: Vice (disguised as Happiness) offers a life of easy pleasure; Virtue offers a life of hard but genuinely rewarding labor. Virtue's speech is one of the great documents of Greek moral thought — arguing that genuine goods require effort, that pleasure without achievement is empty, and that honor among gods and men comes only through excellence. The story became enormously popular: it was discussed by Cicero, painted by Renaissance artists, set to music by Handel and Bach, and became a standard topic of moral education for two millennia.

On religion, Prodicus advanced a naturalistic theory that the gods originated from human gratitude for useful natural phenomena: 'the ancients regarded as gods the sun, moon, rivers, springs, and in general everything useful for life — just as the Egyptians deified the Nile.' He reportedly argued that agriculture produced the cult of Demeter; wine, the cult of Dionysus; water, the cult of Poseidon; fire, the cult of Hephaestus — each god originating as the personification of something beneficial. A second stage then deified the discoverers of these goods: Demeter was originally the person who taught agriculture; Dionysus the person who introduced wine. This two-stage theory (natural phenomena first, benefactors second) was influential in antiquity and anticipates modern anthropological theories of religion.

Sextus Empiricus and other sources suggest that Prodicus's naturalism was taken to imply atheism: if the gods are merely projections of human gratitude, they do not exist as independent beings. Whether Prodicus himself drew this conclusion or merely offered a genetic account compatible with conventional piety is debated. Philodemus (On Piety) preserves a tradition that Prodicus was executed for corrupting the youth, but this may be confused with Socrates or simply invented.

Antiphon is one of the most important and most elusive of the Sophists. The fundamental scholarly problem is whether Antiphon the Sophist (author of On Truth, On Concord, and other philosophical works) is the same person as Antiphon of Rhamnus (the orator and oligarchic politician who masterminded the coup of the Four Hundred in 411 BCE and was executed after its collapse). Ancient sources disagree: Hermogenes and the Suda distinguish two Antiphons; Thucydides' famous eulogy of the politician (VIII.68) — 'second to none in virtue of any Athenian of his day' and 'best able both to devise and to express a plan of action' — may or may not describe the same man who wrote radical philosophical critiques of law. The majority modern view (Pendrick 2002, following Wilamowitz) is that they are the same person, but certainty is impossible.

Antiphon's philosophical masterpiece is On Truth (Peri Alētheias), known primarily from two Oxyrhynchus papyrus fragments (POxy 1364, published 1915; POxy 1797, published 1922). The work presents the most radical surviving formulation of the nomos–physis antithesis. Its central argument: 'the dictates of the laws are adventitious, but those of nature are necessary. The dictates of the laws are the result of agreement, not of natural growth, whereas those of nature are the result of natural growth, not of agreement' (DK 87 B44). The practical consequence is devastating: 'a man would use justice to his greatest advantage if he regarded the laws as important in the presence of witnesses, but the dictates of nature as important when alone and unwitnessed. For the dictates of law are imposed, but those of nature are necessary; and the dictates of law are the result of agreement, not of natural growth, whereas the things of nature are natural growths, not the result of agreement.'

This is often read as a practical contrast between legal and natural constraint: legal penalties depend on detection, while natural consequences do not. The 'injunctions of the laws' are external constraints with no binding force beyond the threat of punishment; the 'injunctions of nature' are necessities that harm you regardless of whether anyone is watching. The position is not amoral chaos — it is a rational calculation about which norms actually matter.

The second papyrus fragment contains a remarkable passage on human equality: 'we revere and honour those born of noble fathers, but those who are not born of noble houses we neither revere nor honour. In this we have become barbarians to one another, since by nature we are all constituted alike in all things, both barbarians and Greeks' (DK 87 B44B). This is followed by an empirical argument: all humans breathe through mouth and nostrils, eat with hands, see with eyes — the biological facts make no distinction between Greek and barbarian, noble and base. The conventional hierarchies that structure Greek society have no foundation in nature.

Antiphon also wrote On Concord (Peri Homonoias), which apparently took a more constructive view of social harmony, and he reportedly practiced a form of proto-psychotherapy: he 'set up a booth in Corinth near the agora and advertised that he could cure those in distress by means of speeches, and by inquiring into the causes of their condition he consoled those in grief' (A6) — the first known 'talking cure.' His other interests included dream interpretation, mathematics (he attempted to square the circle by inscribing polygons), and natural science.

Critias was one of the most extraordinary and most troubling figures of the late fifth century — a man who was simultaneously philosopher, poet, dramatist, prose writer, Socratic associate, and ultimately leader of the most violent oligarchic junta in Athenian history. He was born into one of the most distinguished Athenian families: he was a relative of Plato's mother Perictione (the exact relationship is debated — variously reconstructed as cousin, uncle, or great-uncle), and the family traced its ancestry to Solon. He was part of the Socratic circle — Xenophon and Plato both depict him in conversation with Socrates — and his transformation from intellectual to tyrant became one of the most damaging arguments against Socratic education in the popular imagination.

Critias's philosophical significance rests primarily on a fragment from his satyr-play Sisyphus (DK 88 B25), traditionally attributed to Critias though occasionally reassigned in modern debate. In it, Sisyphus describes the invention of religion: 'There was a time when the life of men was disordered, bestial, and subject to brute force; when there was no reward for the good and no punishment for the bad. Then, I think, men established laws as punishers, so that justice might be ruler and hold violence as its slave. But still, while they restrained men from open deeds of violence, they committed them in secret. Then, I believe, some shrewd man, wise in counsel, invented for mortals the fear of the gods — so that there might be a deterrent for the wicked even when they act or speak or think in secret. He introduced the divine: there is a deity, flourishing with deathless life, hearing and seeing with his mind, thinking and attending to all things, bearing a divine nature — who will hear everything spoken among mortals and can see everything that is done.'

The passage is remarkable: it presents religion as a deliberate political invention — a 'noble lie' designed by a 'shrewd man' to extend social control into the private sphere where law cannot reach. The gods function as omniscient surveillance mechanisms, deterring wrongdoing by making secrecy impossible. This is not a theory about the gradual evolution of religious belief (like Prodicus's) but about its conscious fabrication for political purposes. If true, the gods are instruments of power, not realities.

Whether Critias endorsed this view (as a statement of his own atheism) or merely put it in the mouth of a dramatic character (Sisyphus is, after all, a notorious trickster being punished in the underworld) is debated. His political career suggests the former: as leader of the Thirty Tyrants (404–403 BCE), Critias showed no regard for divine sanction or moral constraint. Xenophon (Hellenica II.3–4) records his reign of terror: confiscation of property, summary execution of opponents, eventually the murder of 1,500 Athenians — including his fellow oligarch Theramenes, whom he had arrested during a meeting and executed without trial. He was killed in the battle of Munichia (403 BCE) when the democrats under Thrasybulus retook Athens.

As a literary figure, Critias was considerable. He wrote elegies praising Spartan discipline, prose works on the constitutions of Thessaly and Sparta, tragedies, and philosophical dialogues. Plato named a dialogue after him (the Critias, which describes Atlantis) and made him a prominent speaker in the Timaeus. His prose style was admired in antiquity for its clarity and force. The combination of intellectual cultivation with political brutality made him a cautionary figure — proof, for Plato's enemies, that philosophy could produce tyrants rather than just men.

Lycophron is one of the most tantalizingly obscure of the Sophists — known primarily from a handful of references in Aristotle that suggest positions of considerable philosophical originality. Almost nothing is known of his life; he is sometimes identified as a student of Gorgias, though the evidence is thin. His dates are uncertain, but his ideas appear to engage with late fifth-century debates.

Aristotle preserves Lycophron's most famous doctrine in the Politics (III.9, 1280b10): 'Lycophron says that law is a guarantor of men's just claims upon one another, but is not able to make the citizens good and just.' This is a contractarian or minimalist conception of the state: the political community exists to prevent mutual injustice, not to promote virtue. Law guarantees rights — it is a 'covenant' (synthēkē) rather than an educational institution. Citizens associate for mutual protection and commercial exchange, not for the cultivation of excellence. Aristotle objects that this reduces the polis to a mere alliance and ignores its proper function as a community aimed at the good life. But Lycophron's position anticipates liberal political theory: the state exists to protect individual rights, not to make citizens virtuous.

Aristotle also reports (fragment 91 Rose) that Lycophron rejected the significance of noble birth: 'the nobility of good birth is obscure, and its dignity a matter of words. It has no visible form; its distinction rests on mere opinion.' Birth-status is purely conventional — a matter of words (logōi) and opinion (doxēi), not of nature (physei). This is the nomos–physis distinction applied directly to aristocratic privilege: if nobility is merely verbal — a social convention without natural basis — then the entire hierarchical structure of Greek society rests on nothing but agreement.

A third Aristotelian reference (Physics I.2, 185b27) mentions Lycophron in a logical context: he reportedly eliminated the copula 'is' from predication, saying not 'Socrates is wise' but 'Socrates wise' — apparently to avoid the implication that the subject 'is' (exists as) the predicate. This suggests engagement with Eleatic logic: if 'is' carries existential force, then 'Socrates is wise' seems to identify Socrates with wisdom, generating paradoxes of the one and the many. By removing the copula, Lycophron may have been trying to solve (or dissolve) the problem of predication that Plato addresses in the Sophist.

These three positions — contractarian politics, rejection of nobility, and linguistic reform — share a common thread: the reduction of apparent substance to mere convention. Noble birth seems real but is only words; the state seems natural but is only a contract; predication seems to assert identity but needs not. In each case, Lycophron strips away the conventional appearance to reveal either nothing or something much thinner than tradition assumed.