In English, the term sophist is most often used pejoratively, for one who argues with devious abuses of logic. The Greek Sophistês took on a similar sense in the fifth century BCE., but its original meaning is simply expert or wise person.
In the study of Greek philosophy, the sophists denote a group of teachers and intellectuals of the fifth and fourth century BCE (the term is also used for later practitioners of their profession; this soon comes to be interchangeable with rhetoric or public speaking, as in the so-called Second Sophistic movement of the second century CE).
The sophists are perennially ambiguous and controversial figures, and it has long been debated whether they should be deemed philosophers. Two central points seem clear: First, the sophists did not constitute a philosophical school with a shared set of metaphysical and ethical positions; second, a number of them did develop serious, innovative, and influential ideas and arguments on a wide range of topics, and so demand inclusion in the history of ancient philosophy.
The sophists are best seen as an intellectual movement, comparable to the philosophies of the eighteenth century or the progressive thinkers of Victorian England (some of whom, such as George Grote, were champions of the ancient sophists). As always with such movements, it is debatable who should be counted as a member, and membership is in any case more a matter of shared interests and tendencies than common doctrines.
The leading figures of the sophistic movement so understood include Protagoras, Gorgias, Hippias, Antiphon, and Prodicus. Gorgias was primarily a rhetorician (i.e., an expert in and teacher of public speaking), but the two professions must have overlapped widely, and his surviving texts are among the most important for reconstructing sophistic ideas.
Socrates was often counted among the sophists by his contemporaries, and is used to represent the whole movement in Aristophanes’ Clouds; in a number of dialogues Plato aims to show that he differs from them radically.
Sophistic ideas have also come from some important anonymous texts, such as the Dissoi Logoi and the Anonymus Iamblichi (a long discussion of virtue, apparently of sophistic origin, inserted by the Neoplatonist Iamblichus in his Protrepticus), or of contested authorship (notably the fragment on religion from the satyr play Sisyphus, attributed to both Critias and Euripides).
They can also be found in contemporary historical and medical texts (e.g., Thucydides’Melian Dialogues, the Hippocratic On the Art), as well as comedy and tragedy (especially Euripides). So there is no firm dividing line between sophistic thought and the broader fifth-century Greek culture around them, which was marked by a vigorous questioning of tradition and empirical, naturalistic researches into many subjects (historiê).
Sociologically, the sophists were professional teachers, the first in Greece to offer a higher education in the liberal arts. Sophists (who came from all over the Greek world) traveled from city to city presenting themselves to prospective students through public displays; this could involve giving a set speech (epideixis), performing feats of memory, undertaking to answer any question the audience might pose, or offering question-and-answer refutations of others.
This practice of refutation, usually given the pejorative name eristic, is formally identical to the Socratic elenchus; to differentiate the two, Plato emphasizes that Socrates argues in pursuit of the truth and moral improvement, whereas sophists argue for victory and for money. Some sophists gave displays at the Olympic games, and the sophistic practices themselves were intensely agonistic.
Plato’s Protagoras gives a vivid depiction of a gathering of sophists engaged in argument, banter, and competitive intellectual showing-off. Such sessions served as advertisements to the wealthy young men who made up the audience, encouraging them to sign on for further teaching.
This would be an expensive proposition: The sophists (and above all Protagoras) seem to have charged far more than any other contemporary professionals, and became enormously rich from their teaching. Sophists also served on embassies for their native cities, drafted laws, and wrote books; they were famous and influential—and bitterly controversial—public intellectuals as well as teachers.
Most sophists are said to have claimed to teach virtue (arête), but their curricula and teaching methods varied. In the Protagoras, Protagoras chides Hippias for forcing students to study subjects like mathematics and astronomy; he himself claims to teach them good judgment (euboulia), enabling them both to manage their private affairs and to succeed in politics, and accepts that this amounts to the teaching of virtue.
He also claims that the greatest part of education is the ability to analyze and criticize poetry. So the sophistic teaching of virtue was not a matter of moralistic indoctrination; rather, the sophists taught their students to reflect on traditional values, to analyze and criticize the literary texts that discussed them, and to apply this learning in a political career.
In practice, their teaching seems to have centered on rhetoric or public speaking (hence the blurriness of the line between rhetorician and sophist), which was the key skill for a political career. The connection between teaching rhetoric and teaching virtue is easier to understand if we bear in mind the traditional, Homeric sense of arête as excellence—that is, the skills and personal qualities that make a gentleman successful in his career and a valuable asset to his community.
By teaching the arts of political success, the sophists were teaching virtue in a quite traditional sense. In doing so they prompted debate about just what virtue or excellence really consists in, and in particular about the status of qualities such as justice, dikaiosunê, which seem to benefit the community at the expense of their possessor.
The evidence for sophistic ideas is uneven and very defective. There are several brief, but substantial, works by Gorgias (On Not Being; Defense of Helen), and a few pages worth of Antiphon’s On Truth; but for Protagoras, the leading figure of the movement, only a handful of brief fragments (that is, trustworthy-looking quotations in later authors) survive.Moreover, many of our texts are ambiguous or difficult to interpret.
For instance, both the Dissoi Logoi and Antiphon’s discussion of justice seem to argue for contradictory conclusions; perhaps they are exercises in antilogikê, opposing arguments, a sophistic genre associated with Protagoras. Gorgias’s On Not Being and the Defense of Helen both seem to be exercises in defending the indefensible; whether they also have serious philosophical agendas is still debated.
A further difficulty is posed by the all-important evidence of Plato, who fixed forever the stereotype of the Sophist. Plato vividly depicts sophists in a number of dialogues (Protagoras, Gorgias, Republic [Thrasymachus], Hippias Major and Minor, and Euthydemus), and the Sophist is devoted to defining their nature.
But Plato’s evidence is not consistent: For instance, the Protagoras and the Euthydemus give very different pictures of sophistic argument, and the Protagoras and Theaetetus seem to give conflicting accounts of Protagoras’s ethical views.
Moreover, Plato’s presentation of the sophists is sometimes warped by hostile prejudice (though, as Grote  and T.H. Irwin  have noted, he is not as uniformly hostile as scholars sometimes assume), and by his anxiety to distinguish them as sharply as possible from Socrates.
Unsurprisingly, given the focus of their teaching, sophistic thought seems to have centered on ethical and political topics. However, sophistic interests varied greatly; in some cases they were very broad, and several sophists are associated with ideas in mathematics or natural science.
So the traditional scholarly contrast between the sophists and the pre-socratics, with their researches into natural science, is probably misguided or at least overstated. The sophists also were founders of what are now called the social sciences; they offered theories of the origins of human institutions such as law and religion, and took a particular scientific interest in language and the norms applicable to it.
Here in the social realm, the closest thing to a unifying pattern in sophistic thought is found—their concern to distinguish phusis and nomos (i.e., the natural and the merely conventional or, as one might now say, socially constructed).
Surviving sophistic texts analyze a wide range of human institutions and values—above all, justice—in these terms, with the assumption that nature represents a deeper or more binding norm than convention. Combined with the sophists’ recognition of the differing norms of various cultures (see the Dissoi Logoi) and their skepticism about traditional religion, this privileging of the natural could be seen as undermining the authority of moral tradition.
However, hostility toward the sophists probably had less to do with their particular theories than with their teaching to all comers the ability to speak persuasively, and with it the power to manipulate both political assemblies and legal proceedings.
It is now generally recognized that it is wrong to describe the sophists collectively as moral skeptics, immoralists, or relativists (Bett 1989, 2002). Protagoras is presented as a relativist in Plato’s Theaetetus, but not in his earlier and probably more historically accurate Protagoras. The Dissoi Logoi presents a wealth of evidence for the cultural relativity of values, but argues against relativistic conclusions as well as for them.
Sophistic uses of nomos and phusis were often in the service of conflicting ethical and political theories, and attempts to pin the sophists down to any common moral theory are doomed by the sheer diversity of sophistic thought.
If anything, the sophists (as one would expect given the competitive character of their profession) tended to take up positions in opposition to each other—even if the battle lines are often now blurred by the incompleteness of evidence available.
On matters of natural science, metaphysics, and epistemology, it is still more difficult to identify shared sophistic positions. Antiphon’s On Truth seems to have offered a complete cosmogony on natural science: Aristotle, in Physics, reports him as claiming that the true essence of a wooden bed is wood because if planted it would reproduce a tree rather than another bed.
Presumably the force of the scientific part of the work was to spell out this kind of distinction between the underlying natures of things (the realm of phusis) and merely superficial human arrangements and projections, (nomos).
Gorgias’s On Not Being seems intended to support a skeptical conclusion, at least as a critique of metaphysicians like Parmenides. His main criticism was: If beings do have a real nature independent of humans, it can neither be known or communicated.
Plato’s Theaetetus attributes a sophisticated relativism or subjectivism in epistemology (and ethics) to Protagoras: its slogan, “Man is the measure of all things,” must go back to Protagoras’s work Truth, but how much of the detailed theory presented by Plato that is genuinely Protagorean is uncertain.
Even setting aside other sophistic views (where evidence is even scantier), the most these positions could be said to share is a critical orientation—a tendency to diagnose beliefs and perceptions (both everyday and scientific, or philosophical) as irreducibly subjective.
In keeping with their activities as teachers and writers, and their interest in the analysis of human conventions, the sophists were noted for their researches into language. Prodicus was celebrated for drawing fine distinctions in the meanings of words. It is thought that Protagoras analyzed the parts of speech, and claimed that the words for wrath and helmet, feminine in Greek, were properly masculine.
|feminine in Greek|
The sophists are often associated with claims that falsehood and contradiction are impossible, but the evidence for this is unclear and confusing, and these claims are hard to square with the eristic practice of inducing contradictions in others.
One might suspect that distinctive views about the nature of truth were entailed by Protagoras’s Measure Thesis, and lay behind his practice of argument on both sides of a question (antilogikê); but attempts to reconstruct sophistic ideas on these questions are highly speculative.