In order to understand the meaning and scope of the challenge that the sophists present to us, we must clear the field of all ambiguities and prejudices. All too often the sophist is only taken into consideration as a polemical target, as a counterpart to the philosopher: whereas the philosopher argues in order to seek the truth, the sophist only tries to win an argument; and whereas the philosopher concerns himself with problems in all of their complexity, the sophist instrumentally focuses on fashionable topics that might interest his public of potential pupils (in other words, people willing to pay him). These contrasts are repeated not only in relation to the future, which is to say to Plato and Aristotle, but also, retrospectively, in relation to the so-called ‘Presocratic philosophers’. As a consequence, the sophists find themselves in a sort of no man's land, and their activities appear to mark a break in the history of philosophy, interrupting its toilsome and earnest progression from myth to reason.
Like all schematic reconstructions, the one just provided gives rise to some serious misunderstandings. One initial misunderstanding concerns the very concept of ‘philosophy’: up until the end of the fifth century there was no discipline of ‘philosophy’, possessing a distinctive epistemological status and opposed to other literary genres such as history or rhetoric. Heraclitus – to quote but one figure among those whom we regard as philosophers – uses the term to mock Pythagoras and Hesiod, accusing them of knowing many things without really understanding any at all (22B35 D.-K. = Her. 40D L.-M.). As a non-polemical term of praise, the historian Herodotus calls the poet and politician Solon a ‘philosopher’, commending his thirst for knowledge (1.30.2); along much the same lines, Pericles goes so far as to claim that all Athenians are philosophers (Thuc. 2.40.1). Philosophy, as we understand it, which is to say as an independent discipline, is a later invention by Plato and Aristotle: what we find in the fifth century, rather, are many prose writers (including the sophists) and poets engaging in an all-round debate that touches upon authors ranging from Homer to Parmenides, from Anaxagoras to Simonides. (It is important to remind ourselves that the same kind of openness is also displayed by Plato, Aristotle, and many other ancient philosophers.)
Only by setting out from a correct historical contextualization can we address the delicate question of the sophists’ contribution to the history of ancient thought. The sophists were no doubt interested in language and all the issues related to the problem of language (argumentative techniques, rhetoric, poetry, and literary criticism), since this was the topic which most interested their public, especially in democratic Athens. However, this is not to say that they did not also deal with other ‘philosophical’ problems which the Presocratics had investigated and which Plato and Aristotle were to take up again – quite the contrary.
The vagueness of the concept of ‘Presocratic’ has often led to the misguided attempt to draw a clear-cut distinction between natural philosophers and sophists, spawning the cliché that the former only discussed nature, and the latter the human world. Like all clichés, this one contains both an element of truth and an element of falsehood. It is true that the Presocratics’ investigations chiefly focused on physis (nature), while the sophists concerned themselves with what more specifically pertains to humanity. But it is just as true that the Presocratics made some very important contributions to the study of language and human psychology, and that the sophists also dealt with the problems of physis and human's relationship with the world. In other words, what changes is the perspective, not the topics discussed: the Presocratics searched for the elements of continuity between human beings and reality, while the sophists were interested in the issue of what distinguishes humankind. The change of perspective, however, does not depend on any lack of interest of the latter towards the former: it is the consequence of a critical engagement.
Ancient sources repeatedly bear witness to the sophists’ interest in the Presocratics’ physis. The most significant example is provided by Gorgias’ treatise On Nature or On Not-Being, which from its very title sets out to overthrow the theses of Melissus and Parmenides (Gorgias, after all, was a pupil of Empedocles: see 82A3, 10 D.-K. = 32P4–5 L.-M., and Kerferd 1985). Protagoras (80B2 D.-K. = 31D7, R2 L.-M.), Lycophron (83.2 D.-K. = 38D1 L.-M.), and probably Xeniades (81.1 = 39R1 L.-M.) also polemicized against Parmenides and Zeno. Cicero states – unfortunately, in a very succinct way – that Prodicus and Thrasymachus, too, investigated the nature of things (De natura rerum, 84B3 D.-K. = 34D2 L.-M.; and 85A9 D.-K. = 35D4 L.-M.); and Aristophanes describes Prodicus (and the sophist Socrates) as a ‘meteorosophist’ (which is to say, an ‘expert on celestial phenomena’: 84A5 D.-K. = Dram.T22–4 L.-M.).Footnote 1 Finally, recent studies have quite rightly emphasized the relationship between Antiphon and Democritus; and the former's relationship with Anaxagoras is yet to be fully investigated.Footnote 2 This succinct outline is enough to bring out an evident yet largely overlooked fact: the sophists were not interested in the thought of the natural philosophers in general (this category being so broad as to prove generic); rather, as one would expect, they focused on the more recent natural philosophers, starting from Parmenides and the Eleatic school. By and large, the investigations conducted by many sophists constitute a response to the great challenge of Parmenidean monism and an attempt to defend the multiplicity of our world – although many details are yet to be clarified. In this respect, the sophists’ reflections run parallel to and intersect with those of the so-called pluralists: Empedocles, Anaxagoras, and Democritus.
In the following pages, I will endeavour to assess the importance of this engagement. But before proceeding any further, it is necessary to get back to a crucial point, namely the fact that the sophists do not constitute a homogeneous school: just as they argued with their predecessors, they heatedly argued with one another. As we will see, many of Antiphon's theses gain significance in opposition to Protagoras, and much the same probably holds true for Gorgias, Xeniades, and Lycophron. This also confirms the richness and liveliness of the debate, which gave rise to some fundamental philosophical positions that Plato and Aristotle were bound to engage with.
Protagoras’ truth: the epistemological interpretation
One of Protagoras’ most famous treatises was entitled Truth. In itself, this title is revealing of the ambitions that lay behind it: ‘truth’ was a key term for the Presocratics (Detienne 2006);Footnote 3 in choosing it, Protagoras clearly sought to enter into the debate by challenging a long-established tradition. The first sentence of the treatise fully confirms its author's provocative intentions: ‘Of all things the measure is man: of those that are, that they are; and of those that are not, that they are not’ (80B1 D.-K. = 32D9 L.-M.; for the sake of convenience, in the following pages this sentence will be abbreviated as ‘man-measure’).Footnote 4
‘Man-measure’ is one of the few authentic Protagoras fragments to have been preserved, and many ancient sources confirm that the statement was originally formulated precisely in these terms. The problem, however, is its opacity: even in antiquity there was intense debate concerning what Protagoras really meant, and modern readings have only increased doubts about its content. As a matter of fact, it cannot be ruled out that a certain degree of ambiguity was intentional. Truth was not a scientific treatise but, in all likelihood, an epideixis, the text of a public performance. In opening his speech, Protagoras sought to capture the attention of his audience (or reader) by making a striking and allusive claim – at the expense of exactness and precision – and putting aside all caution and hesitation (which are hardly the most valuable qualities for a public performance). There is nothing strange in any of this, since a desire to capture the audience's attention was quite typical of the sophists, as is confirmed by many other sources.Footnote 5
This is not to say that the ‘man-measure’ thesis had no specific meaning. Simply, it is a matter of dealing with potentially ambiguous elements. In particular, it is necessary to clarify the notion of man: that is, whether ‘man’ refers to each individual or to humanity in general; in discussing this issue, the meaning of the other terms that make up the sentence will also become clearer. In turn, this will help us assess the underlying meaning of Protagoras’ statement and its field of applicability, so as to determine whether it is an epistemological thesis (a thesis concerning knowledge) or whether it also carries practical or political implications. By way of anticipating my argument, I note here that the sentence can be read on different levels, in line with the archaic logic according to which there is no need to clearly distinguish the different meanings possessed by a term.
There are three main sources for the ‘man-measure’ thesis: Plato, Aristotle, and Sextus Empiricus (a second-century ce sceptic). All three understand the phrase – at any rate at a primary level – as though ‘man’ referred to ‘each individual’. The most interesting testimony is in all probability that of Plato, who repeatedly engages with Protagoras’ thought in his dialogues, especially the Theaetetus and Protagoras. In the Theaetetus, Socrates and the young mathematician Theaetetus extensively discuss the ‘man-measure’ thesis, regarding Protagoras as an early empiricist thinker. The Protagorean phrase is equated with the claim that ‘knowledge is sensation’, and paraphrased as follows: ‘just as each thing appears to me, so too it is for me, and just as it appears to you, so too again for you’. Thus, if the wind appears warm to me, it is warm for me; and if it appears cold to another person, it is cold for him or her (Theaetetus, 152a = 80B1 D.-K. = 31R5 L.-M.). In other words, ‘man-measure’ means that each person is the measure of his or her own sensations, and Protagoras emerges as a staunch supporter of an empiricist epistemology that grounds knowledge in sensory data.
Plato's testimony is crucial and his reconstruction is also taken up by other authors (see 80A16 D.-K. = 31R28 L.-M. and 70B1 D.-K.). In and of itself, however, it is a reductive interpretation that risks proving misleading, as far as the meaning of ‘man’ is concerned. The limits of Plato's testimony become quite evident if we consider the underlying aim of the Theaetetus, which is not to accurately report the theses of Plato's opponent, but to show their philosophical limits. According to Plato, the ‘man-measure’ thesis is a muddled one; the only way to make it clear is by assuming that Protagoras was only speaking of sensations; and since (according to Plato) it is impossible to base knowledge on sensations alone, it follows that the thesis is fallacious. In other words, the discussion on Protagoras is intended to be a refutation of his thesis. The point here is not to evaluate the legitimacy of Plato's criticism (who anticipates or inaugurates one of the most important problems in the history of philosophy, namely the clash between rationalism and empiricism). What matters is the fact that a strict empiricist reading stems from a polemical interpretation, which may be philosophically legitimate but is not historically reliable: clearly, Protagoras was not speaking of sensations alone. Remarkably, Plato himself suggests that Protagoras’ phrase had a broader meaning between the lines of the Theaetetus, in certain passages where it emerges that ‘man-measure’ also concerned all opinions and judgements (see 157d and 170a–171a). Aristotle and Sextus Empiricus further confirm the need for a broader interpretation: what are at play are not just sensations but more generally all opinions and judgements (and especially value judgements). ‘Man is the measure of all things’ means that each individual is the ultimate arbiter of all of his or her own judgements – that the wind is warm or cold, but also that performing a given action is right or wrong.Footnote 6
The point just made is crucial in order to reconstruct the overall meaning of Protagoras’ position. The transition to a broader conception of human activities (not only sense-perceptions but human judgements as a whole) brings out one aspect of the thesis that scholars have all too often overlooked. Usually it is taken for granted that Protagoras’ thesis concerned problems related to human knowledge and that these problems were addressed in abstract terms, by examining the general ways in which the process of knowledge acquisition unfolds – in other words, by investigating what happens to a subject X who at a given moment t experiences sensation f (let us think of the example of the wind). Yet this is not correct. It is certainly true that Protagoras’ thesis was concerned with human knowledge. However, it is not true that it focused on it in an ‘abstract’ way, as though humans were ‘automata’ that can be stimulated from the outside so as to study their reactions at given moments and in specific circumstances. This approach might work in the case of the wind, but not in that of judgements concerning what is good or bad. ‘Man’ refers to the individual, yet not to an abstract subject: Protagoras has concrete, historically well-defined people in mind, with their ideas and prejudices. What is meant by ‘man’, therefore, is each person with his or her own personal history, experiences, and expectations: that is, people for whom some options are possible while others are not, and whose judgements largely reflect their individual experience – people who are responsible for the opinions they have and for what they do. When I claim that a certain thing or action is good (or beautiful or unjust), I do so on the basis of a series of ideas and opinions that I have acquired over the course of my life and that I have continued to put to the test through my engagement with facts – in other words, on the basis of my experience, which is different from that of other people. The true measure, then, is not ‘man’ in the abstract sense but rather each individual's experience.Footnote 7 The ultimate purpose of Protagoras’ statement is to re-evaluate human experiences; as we shall soon see, it also carries a polemical undertone with respect to the previous tradition.
Having clarified the meaning of ‘man’, we can now turn to consider the second part of the phrase, ‘of those that are, that they are; and of those that are not, that they are not’. Essentially, it is a matter of clarifying what ‘things’ means and in what sense man ‘measures’ them. Based on what has been noted so far, we can reasonably claim that what Protagoras meant by ‘things’ was not just material objects and entities (things that can be perceived by the senses, such as wind): ‘things’ are to be understood in their broadest possible sense as ‘facts’ – for example, the wind, but also an event such as performing a certain action, and all that happens to man. In this respect, the term chosen by Protagoras is highly revealing. Chrema derives from the verb chraomai, meaning ‘to treat’, ‘to use’, ‘to entertain a relation with’: according to its original meaning, the term describes not so much ‘things’ in themselves (for in this case Protagoras could have used onta or pragmata), as in their relation to us; the emphasis is on the way in which we relate to things, use them, judge them, and so on. ‘Things’, then, means everything which human beings enter into contact with: material objects but also events and occurrences – in other words, facts.
As far as the notion of measure is concerned, it is clear that man is the measure not of the existence of things (such as the wind or the occurrence of a certain action), but rather of the way in which things present themselves (for example, as warm/cold or good/bad). The expression, that is, must be understood not in an existential sense (in which case it would be difficult to understand what it means for man to be the measure of the non-existence of the things that are not), but rather in a modal-predicative sense. Protagoras is not denying the existence of the external world, but only limiting the possibility of knowing it to the way in which it presents itself to our experience (hence, if I judge the wind to be warm, I am the measure of the fact that it is warm and not of the fact that it exists; if I judge the wind not to be warm, I am measure of the fact that it is not warm and not of the fact that it does not exist). Things in themselves do not possess any predetermined truth or any intrinsic value: they simply exist, they are what surrounds a person, what happens to him or her. What matters is the way in which we relate to them: each individual, according to his or her experience, is the judge of these facts, insofar as he or she assigns them a degree of consistency or value.
This initial reconstruction also enables us to evaluate Protagoras’ position with respect to the previous intellectual tradition: ‘man-measure’ emerges as a polemical response to the enquiries on physis conducted by many Presocratics, and in particular to Parmenides’ monism.Footnote 8 Protagoras’ interest in critically engaging with the Eleatic school is confirmed by other sources: in particular, Porphyry (a third–fourth-century ce Neoplatonist) informs us that Protagoras wrote a treatise On Being (regrettably lost) against those who ‘uphold the uniqueness of being’ – clearly, Parmenides and his disciples (80B2 D.-K. = 31D7, R2 L.-M.); a polemic with Zeno is also attested.Footnote 9 The same polemical intentions are suggested by Plato's Theaetetus, which presents Protagoras and Parmenides as the leading exponents of two opposite ways of conceiving reality, namely as becoming and as being.
Once again, although Plato's testimony is crucial, it must be examined with great caution, so as to avoid pushing our interpretation of Protagoras too far. The Theaetetus ascribes a sort of radical Heracliteanism to Protagoras that presents reality as the constant flow of all things, a flow so incessant that we should speak not of ‘being’ but only of ‘becoming’. On the opposite side of the spectrum, according to the dialogue, stands Parmenides, the philosopher of the stability of being. This thesis, however, is conditioned by the empiricist interpretation, whose limits I have already highlighted: if we only speak of sensations, it is clear that what we have in mind is a world exclusively made up of material objects (since sensations are only engendered starting from material things, such as a table or the wind); and if sensations vary (in the sense that the wind will appear warm at one time and cold at another), this occurs because material reality varies, changing constantly. In other words, the notion that Protagoras supported a fluxist interpretation of reality rests on the assumption that he was referring to sensations alone. But this, as we have seen, is a reductive interpretation. Significantly, Plato referred to this thesis as Protagoras’ ‘secret doctrine’ (Theaetetus, 152c), thereby revealing that it was not a thesis openly upheld by the sophist, but rather a position that in his view could legitimately be inferred from his claims.Footnote 10
Protagoras’ engagement with Parmenides does not actually take place on the ontological level. His main interest was not to oppose a different (and truer) world to that of Parmenides (the world of becoming to the world of being, as Plato would have it) – a cosmology capable of accounting for the multiplicity of natural entities.Footnote 11 In this respect, Protagoras differs from the so-called ‘pluralist’ philosophers Empedocles, Anaxagoras, and Democritus, who, in response to Parmenides, had sought to ‘save the phenomena’. Protagoras rather set out to ‘save man’: his challenge was a more radical one, and it targeted the very assumptions on which Parmenides’ reflection rested. For Parmenides (like many other natural philosophers), terms such as ‘man’ and ‘opinion’ were synonymous with error, by contrast to the truth and being: in his view, the purpose of philosophy was to investigate the universal and absolute first principles. Even the multifaceted world of humankind was to be investigated with the same perspective, by identifying its points of contact with being and subordinating what is relative or contingent within it. In other words, Parmenides (a) had drawn a clear line between the true world of being on the one hand and the world of appearances and becoming on the other, while (b) asserting the possibility of a privileged form of knowledge that moves beyond the illusory world surrounding us in order to reach true reality (the truth of being), and (c) discrediting ordinary human knowledge (unfounded opinions).
Protagoras opposed all these assumptions: (b) because nobody enjoys privileged access to these alleged higher ‘realities’; (a) because no-one can ignore the reality that surrounds us, and which is our one and only world; and (c) because it is not true that the world that surrounds us is helplessly muddled and corrupt, since through our judgements we are capable of ‘measuring’ it and giving it an order – which is to say, of knowing it. There are no wise men and ignorant people, then: each man can legitimately express his own opinions and judgements. Protagoras reverses Parmenides’ perspective, reappraising the uniqueness of human experience, which is always relative and contingent: this relativeness and contingency is not a limit but rather the condition on the basis of which we relate to things. Instead of developing hypotheses on the nature of the all, we should shift our focus back to our everyday life in order to solve the problems affecting it. This was the programmatic (and polemical) message conveyed by the first sentence of the treatise on Truth, as discussed by Versenyi:
The things we are concerned with are chremata, i.e. things we are decisively related to; thus there is no point in speaking in a grand manner about what things may or may not be in themselves; what we have to take into account and concentrate on is what they are for us, in the world we live in, in a world in which our relationship to things, our living in the world, is decisive.Footnote 12
Protagoras’ position has been described in many different ways. Much emphasis has been placed on his ‘subjectivism’, stressing the importance of the subject for the sophist; yet interpreters have also spoken of ‘objectivism’, noting once again that the ‘man-measure’ thesis presupposes a real and concrete relation with reality.Footnote 13 Other scholars have spoken of phenomenalism, stressing the fact that reality always presents itself as a phenomenon, as that which appears. Like all ‘-isms’, these classifications are valid as long as we remember that they are merely tools that may help identify the important aspects of Protagoras’ thesis, and not formulas that miraculously explain everything. Given this caveat, the category that probably best describes the particularity and originality of Protagoras’ thought is that of relativism.Footnote 14 Knowledge always depends on the existing circumstances and the knowing subjects, which is why it makes no sense to speak of a single and absolute truth: truth is the relationship which each person establishes with surrounding reality. There is no one absolute truth, only as many truths as there are perceiving and judging subjects.
Protagoras’ truth: the practical and political consequences
The thesis that man is the measure of his own judgements faces two serious objections: the charge that it is self-refuting and the charge of solipsism. Protagoras was at least partly aware of these two difficulties, and clarifying them will help us bring out the richness and significance of his thesis.
The charge of being self-refuting (or peritrope, as the ancients called it: literally, the charge of ‘tripping up’) was apparently formulated for the first time by Democritus (80A15 D.-K. = 68A114 D.-K. = 31R22 L.-M.) and then further developed by Plato (in the Theaetetus and Euthydemus) and Aristotle (in the fourth book of the Metaphysics). In brief, this accusation states that, if all judgements are true (this being the implicit meaning of the ‘man-measure’ thesis), then the judgement that ‘man-measure’ is false is also true; hence, ‘man-measure’ is false. Protagoras had further claimed that ‘it is not possible to contradict’ (80A19 D.-K. = 31R10 L.-M.) and this led Plato and Aristotle to add that the sophist denied the principle of non-contradiction, suggesting another version of the peritrope charge: Protagoras claims that all judgements are true (let us call this thesis P) and his opponent that Protagoras’ claim is false (non-P); but, according to Protagoras, contradiction is impossible and therefore non-P is compatible with P. But in this case, non-P is true; hence, P is false.Footnote 15
The soundness of this criticism has been the object of a heated scholarly debate, yet no shared solution has been reached.Footnote 16 Protagoras could nonetheless resort to a few arguments to defend his views. The accusation omits the qualifiers ‘for me’ and ‘for you’, which are crucial to the ‘man-measure’ thesis. By introducing these qualifiers, Protagoras could reformulate the peritrope charge in such a way as to neutralize it: if what I judge is true and I judge that Protagoras’ thesis is false, it does not follow from this that Protagoras’ thesis is false in an absolute sense, but only that it is false ‘for me’. And the fact that it is false ‘for me’ does not prevent it from being true for other people: it remains true, for instance, for Protagoras, who can thus avoid the charge that he is tripping himself up (as well as denying the principle of non-contradiction).
This defensive strategy, however, is potentially open to an even more serious charge, that of solipsism. This risk is clearly present in the aforementioned thesis that it is ‘impossible to contradict’. The thesis in question is fully compatible with ‘man-measure’, for if each individual is the measure of his or her own world of sensations and judgements, contradiction can only be apparent: each individual entertains a relationship with things whose truth-reality cannot be contradicted or disputed by others. Still, it is just as evident that people differ, since some maintain what others deny. But how can we deal with these divergences and oppositions, if everyone is right? If this is how things stand, what follows is a radical (and intolerable) form or solipsism, whereby the fact that each person is his or her own judge makes it impossible to decide things with others. The price that Protagoras must pay in order to defend the consistency of his doctrines seems far too high.Footnote 17
In this case, too, Protagoras has a number of good arguments on his side. Up until this point, the discussion has centred on the problem of ‘truth’, a concept the importance of which can hardly be disputed. However, no matter how central it may be, truth is not the only criterion that governs human thoughts and actions. Alongside truth there are other, equally important criteria. One is ‘what is useful’: all judgements are true, but some are more expedient than others. And this is what matters the most for Protagoras. To exploit a compelling formula, Marcel Detienne described the Presocratic thinkers as ‘masters of truth’; Protagoras (along with all sophists) might instead be called the ‘master of usefulness’.
Once more, with regard to what is useful, the most important testimony comes from Plato.Footnote 18 As we have seen, the main object of the Theaetetus is knowledge, and it is in relation to this problem that Plato introduces, discusses, and criticizes Protagoras’ thesis. However, the dialogue also features a lengthy digression that, while it does not directly touch upon epistemological problems, nonetheless helps to clarify Protagoras’ perspective in all of its complexity: this is the so-called ‘Apology of Protagoras’ (166a–168c), a lengthy speech that Protagoras would have delivered, had he had the opportunity to take part in the dialogue (the dialogue of the Theaetetus takes place in 399 bc, the year of Socrates’ trial, by which time Protagoras had already died). In his fictional reply, Protagoras accuses Socrates of playing the sophist and of intentionally deceiving his interlocutors by playing on the affinity between the words ‘to know’/‘to have knowledge’ and ‘to be wise’/‘to have wisdom’. But, the sophist continues, the truth-value of a type of wisdom is one thing, the value of its contents another: if we are to reason correctly, we must not confuse these two things. Unlike the former, which is changeless, the latter varies: from the point of view of knowledge and truth, every individual is a measure, and the fact that each person is a measure depends on his or her relationship with the things that surrounds him or her – this is a fact. But from the point of view of the value of the contents (of wisdom), it cannot be ruled out that some people are capable of showing the individual how to establish a more expedient relationship with reality.
Socrates puts the following words into Protagoras’ mouth:
For I myself say that the truth is just as I wrote it: each of us is the measure of the things that are and of those that are not, but one person differs enormously from another precisely inasmuch as things exist and appear to be something for one person, something else for another. As for wisdom (sophia) and the wise man (sophos), I am very far from saying that they do not exist; but I also call the man wise who, by transforming things, makes them appear to be good and be good for someone to whom they appeared to be bad and were bad.
(Theaetetus, 166d = 80A21 D.-K. = 31D38 L.-M.; transl. after L.-M.)Thus, to a sick person food will appear bad and be bad: it would be meaningless to argue that the sick person is wrong to say that food tastes bitter to him or her. However, there is someone, namely the doctor, who can help the sick person build a more expedient relationship with reality, by ensuring that food will taste sweet, not bitter, to them. Protagoras’ aim is not merely to abolish the idea of truth, which is shattered into an endless number of private truths; his aim is to replace this criterion with another, more effective criterion – that of what is useful. It is by reflecting on the issue of what is useful that the sophist, while respecting everybody's opinion, shows his wisdom. For, ultimately, what is useful varies from one situation to the next (80A22 D.-K.), and the sophist's task is to identify what is truly expedient in each case. Therefore, just as the doctor helps the patient's body, so the sophist can help his patient build a better, more expedient relationship with reality: relying on his experience, the sophist can help his pupil evaluate his or her beliefs and whether he or she regards them as being truly important, or whether they are merely values that he or she has passively inherited from tradition. The sophist can verify whether the pupil's system of values is consistent, or whether it includes contrasting beliefs. Finally, the sophist can give the pupil advice on how to set out to achieve his or her goals. In brief, we may conclude that Protagoras teaches only one, fundamental thing: how to judge well on the basis of the existing circumstances.Footnote 19
By focusing on the criterion of what is useful, Protagoras can thus justify his teaching within a context in which the space for truth has been substantially limited: the wisdom he claims to possess does not stem from any privileged access to an imaginary higher realm of ultimate truths from which other people are barred. Rather, his wisdom is based on his experience and his capacity to master arguments and problems: it is a human form of knowledge that is never conclusive but nonetheless has its usefulness, insofar as it can help the pupil understand what is best for him or her and how to achieve it. Protagoras’ teaching takes the form not of a transmission of data and information, but of a means to establish a more effective relationship with reality.
The significance of Protagoras’ wisdom emerges even more clearly in relation to political problems, the field in which he most flaunted his competences. In a famous passage from another Platonic dialogue, the Protagoras, the sophist claims that what he teaches is essentially how to make the best decisions with respect not only to private matters but also (and especially) to the affairs of the city, noting immediately afterwards that this is the ‘political art’ (politike techne).Footnote 20 The object of politics is the contrast between the potentially conflictual values of different people: everyone has his or her own ideas, values, and aims. However, these values and aims often differ or even clash, and this creates the premises for conflict. Here is where the opportunity arises for the sophist to intervene. Like everyone else, Protagoras cannot claim to objectively know what is good or expedient in absolute terms. But, unlike many other people, he possesses certain practical competences and knows how to foster a critical reflection among citizens to help them reach an agreement on what is best for everyone – to help them identify those values (which are not absolute values, but ones that can always be reappraised) that make it possible to establish a better relation among the individuals of the community, as well as with reality. The sophist can do so not only in those rare cases in which he can directly participate in the political life of a city, but also indirectly, by teaching his pupils to become good politicians, which is to say politicians capable of building a consensus that will defuse the risk of conflict. In both cases, Protagoras’ wisdom proves crucial for the life of the polis, and in particular for that of a democratic polis such as Athens.Footnote 21 Protagoras’ wisdom is not divine but human and, most importantly, political.
To conclude, we can reappraise the overall meaning of the ‘man-measure’ thesis. The introduction of the criterion of what is useful entails a significant shift of perspective. The thesis undoubtedly concerns the problem of knowledge, but it is important to stress that it is not limited to epistemological issues; rather, one might argue that Protagoras is chiefly concerned with the problem of knowledge in relation to its practical consequences. The problem of truth is not just an epistemological problem, but also a practical one. Consequently, the term ‘man’ acquires a different meaning as well. The object of ‘man-measure’ is not just individuals but humans in their mutual relations. Protagoras’ statement therefore implies increasing degrees of complexity, leading from the individual to the polis (understood as a human community): if I am the measure of my own judgements, then we as members of our community are judges of our own decisions. In this sense, it is possible to note that ‘man’ stands not just for every individual but for human beings in general, who in the absence of absolute truths jointly establish those values which will enable them to live together in the best possible way.
A detailed analysis of the available sources thus reveals the significance and richness of the ‘man-measure’ thesis, which fully confirms the programmatic value that Protagoras sought to assign to it by employing it as the opening sentence of Truth. The statement has different, mutually compatible, interpretative levels, which reveal the complexity of the human dimension. The ‘man-measure’ thesis tackles the problem of human knowledge – of what humans can know and how; in this respect, it upholds the importance of each individual's experiences, in open opposition to the previous philosophical tradition. The thesis, however, also concerns practical matters: not just what we can know and how, but how we can act. As we will see later on, political reflection arguably constitutes the most interesting aspect of Protagoras’ speculation. What is important to note at this stage is that the political aspects of his thought, of which he was so proud, closely depend on his ontological and epistemological theses, in the light of which he defines the human experience.
Gorgias: the dialectic of not-being
Even more provocative than Protagoras’ Truth was Gorgias’ text On Not-Being or on Nature (82B3 D.-K. = 32D26 L.-M.). ‘Nature’ was a key term for Presocratic thinkers, who used it to describe reality as a whole. Nature, in other words, coincides with total reality, with that which is: with being, as the Parmenidean Melissus had concluded by entitling his treatise On Nature or On Being. If, as would seem to be the case,Footnote 22 the title was indeed chosen by Gorgias himself, what we have is a paradoxical equating of reality with nothingness.Footnote 23 Gorgias’ treatise represents the complete ‘overturning’ of the Presocratics’ grand investigation of nature, or rather its negation: in typical fashion, the sophist's argument rests on an intellectual tradition in order to overthrow it.Footnote 24
Regrettably, the original text is lost – and with it, in all likelihood, many of the subtleties of Gorgias’ style and arguments. Still, the sources at our disposal give us a good enough idea of the content of this treatise and of the genuine tour de force that Gorgias imposed on his public.Footnote 25 As far as we can tell, the text consisted of a tight sequence of arguments in defence of three paradoxical theses: ‘Gorgias says that nothing is; and if [sc. something] is, it is unknowable; and if [sc. something] both is and is knowable, it cannot be indicated to other people’ (M.X.G. 979a12–13 = D26 L.-M.). What were Gorgias’ more general aims? In order to answer this question, we need to examine the arguments used in support of each of the three theses. In favour of the first thesis, according to which nothing exists, Gorgias put forward two series of arguments, by developing some personal arguments and by dialectically exploiting his opponents’ theses (the anonymous author of M.X.G. explicitly mentions Melissus and Zeno: 979a22–3). In ‘Gorgias’ own argument’, the chief topic of discussion is the crucial contrast between being and not-being (979a25–33); in the dialectical demonstration, what Gorgias investigated was instead some of the fundamental properties of being, such as the fact of being generated or ungenerated, one or many (979b20–980a8).
The aim of the first argument is to demonstrate that neither being nor not-being can exist, which leads to the conclusion that nothing is.Footnote 26 In order to reach this goal, Gorgias develops his argument in two stages: first he establishes the identity between being and not-being, demonstrating that even not-being is; from this he derives two consequences that lead to the impossibility of both being and not-being, and hence to the conclusion that nothing is. The argumentative structure is always the same: (a) first Gorgias establishes a starting assumption; (b) then he explicates what follows from it; (c) he explains the reasons for this consequence; and finally (d) he draws his conclusions. Here is a schematic reconstruction of the whole passage:
I. Identify being with not-being
(a) starting assumption: if not-being is not-being;
(b) consequence: what is not is no less than what is is;
(c) explanation: for what is not is what it is not, and what is is what it is;
(d) conclusion: hence, not-being is as much as being.Footnote 27
This conclusion raises two distinct problems (not-being is; not-being is in a similar way to being), which are analysed as follows:
II.1. First consequence
(a) starting assumption: if not-being is;
(b) consequence: being, its opposite, is not;
(c) explanation: for if not-being is, then being, its opposite, is not;
(d) conclusion: hence, nothing is.
II.2. Second consequence
(a) starting assumption: if being and not-being are the same thing;
(b) consequence: being is not;
(c) explanation: for what is not is not-being, and hence even what is is not-being;
(d) conclusion: hence, nothing is.
As has rightly been observed, ‘G[orgias]’ own argument’ presents ‘a novel exploration’ of the notion of being and not-being, thanks to its polemical reworking of Parmenides’ theses.Footnote 28 Indeed, the meaning of the first thesis becomes clearer if we view it in relation to a fundamental verse from Parmenides’ poem.Footnote 29 In presenting the two paths – that of being, which alone can be travelled, and that of not-being, which cannot even be spoken or thought of – Parmenides had written with regard to the latter ‘that it is not and that it is necessary for it not to be’ (28B2, 5 D.-K. = Parm. D6 L.-M.; my translation). What is the subject of this sentence? Scholars have long debated this issue; on his part, Gorgias seems to understand the ‘is not’ of the first hemistich as the subject of the second part of the verse, as though the meaning of the sentence were: it is not and it is necessary for what is not not to be. Gorgias thus exploits the ambiguity of Parmenides’ use of the verb being in support of his own paradoxical thesis: his reasoning rests on the observation of the fact that if we claim that what is not is not, then we are de facto implying that what is not is something, namely what is not – just as what is is something, namely what is.Footnote 30 To be more precise, the ambiguity lies in the double meaning which Parmenides apparently attributes to the verb ‘to be’: an existential and a predicative meaning. The verb ‘to be’ is existential insofar as to claim that being is is tantamount to claiming that being exists; and it is predicative insofar as to claim that being is indicates the essential property which distinguishes it – a property that Parmenides clarifies further on in his poem, when he explains that the fact of being implies the fact of being ungenerated, imperishable, and so forth (if what is truly is, then it must be ungenerated, since if it were generated, it would previously have been other than what is and hence not-being, and so on: see 28B8 D.-K. = Parm. D8 L.-M.).
Gorgias’ innovation lies in the fact of having applied this reasoning no longer to being but to not-being: if the essential property of what is is to be, the essential property of what is not is not to be; with regard to what is not, it must be possible to legitimately claim that somehow it is, namely that it is that which distinguishes not-being (predicative sense), and hence that it somehow exists (existential sense). Gorgias, in other words, brings out the tension created by the equivalence (or lack of distinction) between the predicative and existential meanings of the verb ‘to be’. This lack of distinction also explains the two following passages: whereas in the first consequence the focus is on the existential meaning (if not-being is, being, its opposite, is not), in the second one the focus is on the predicative meaning (being is not-being: if being is identical to not-being, then being too is not-being, and hence is not). Certainly, this undue transition from one meaning of the verb ‘to be’ to the other risks to invalidate the formal correctness of Gorgias’ refutation. But Gorgias might have objected to this that what he was doing was merely reproducing an ambiguity already to be found in Parmenides, simply applying it to not-being rather than being.Footnote 31 In this respect at least, insofar as he successfully combined being and not-being, Gorgias could have effectively defended his thesis that nothing is: for Parmenides himself had observed that the equating of being and not-being ‘simply reduces both to the negative level of non-existence’.Footnote 32
In the ‘dialectical argument’, Gorgias targets the speculative activities of all the Presocratics, and not just the theses of the Eleatics. Yet in this case, too, the Eleatics are Gorgias’ privileged point of reference, as may be inferred from the discussion on the generated or ungenerated character of being, which probably represents the most successful example of Gorgias’ way of arguing.Footnote 33 Gorgias accepts the arguments put forward by the Eleatic school regarding the impossibility for being to be generated, and adopts the thesis that being could neither be generated from what is (for, in changing, what is would no longer be what is), nor from what is not (for nothing can be generated from what is not: nihil ex nihilo). Hence, being is not generated. The problem, however, is that being is not ungenerated either, contrary to what the Eleatics liked to claim: Gorgias refutes the Eleatics on the basis of their very own theses, by leading the arguments that Melissus and Zeno had produced into contradiction. According to Melissus, if being were ungenerated, it would also have to be infinite. This leap from the temporal level to the spatial one might seem questionable to a modern reader, but it was explicitly upheld by Melissus (30B2 D.-K. = Mel. D3 L.-M.) on the basis of the assumption that generating something means giving it form, determining it; conversely, being ungenerated means being formless, indeterminate – and hence infinite. Once this has been granted, it is easy for Gorgias to refute the Eleatics’ thesis by invoking Parmenides’ other great pupil: Zeno (29A24 D.-K. = Zen. D13a L.-M.) allows us to argue that if being were infinite it would be nowhere, since to be somewhere is to be contained by something and this is impossible for what is infinite. Hence, if being were ungenerated, it would be nowhere and therefore would not be at all. But if being is neither generated (as many Presocratics liked to think) nor ungenerated (as the Eleatics argued), then it is not: nothing is.Footnote 34
The flow of Gorgias’ texts always produces a baffling effect on the reader/listener. After having demonstrated that nothing is/exists, Gorgias admits that something might be/exist after all: but, even if it did, it still would not be knowable. This is the aim of the second thesis. Regrettably, the text of the anonymous M.X.G. is very corrupt here and it is almost impossible to come up with a definitive reconstruction. One plausible solution features the intertwining of two arguments.Footnote 35 The first is a paradoxical argument, which sets out once again from a Parmenidean premise, namely the close identity between being and thought (28B3, B8, 38 DK = Parm. D6, D8, 38 LM): if someone thinks of something (if he or she has something in mind), that thing is; but this means that if someone thinks of a chariot flying across the sea, then there is a chariot flying across the sea. As this is patently absurd, the conclusion is that external reality does not always coincide with what we have in mind:Footnote 36 the problem is precisely to distinguish between what is true and what is false, which is to say to choose one mental state over another. This marks the beginning of the second argument, which introduces sense-perceptions by assimilating them to judgements (the introduction of sense-perceptions once again shows that Gorgias did not have the Eleatics alone in mind; rather, this second part of the reasoning seems to run against ordinary assumptions about knowledge). For, ultimately, sense-perceptions also concern thoughts: if I see a thing, that thing is in my mind. But, as has just been noted, if a thing is in my mind, that thing is, which leads to absurd results; hence, not even sense-perceptions are always reliable. However, if neither judgements nor sense-perceptions correctly represent reality, we are no longer capable of grasping the truth – we no longer have any way of understanding which of the things we think truly exist. The truth might exist and it might even be thinkable, but we will never know whether we have thought it. And this is tantamount to saying that, even if being is, it is unknowable.
In the transition from the second to the third thesis, Gorgias concedes what he had first denied: after having established that being is unknowable, he allows that it might be knowable; but even if it might be knowable, it cannot be communicated to other people. Besides, we may grant that reality exists, and that we know reality, but we cannot grant that we can communicate our knowledge. This, as we shall see, is the most important point for Gorgias, a point that is never disputed in the treatise. He appears to adduce three arguments in defence of the third thesis (in this case, too, the text is corrupt – the most convincing analysis remains that of Mourelatos 1985). The first argument rests on the assumption of the heterogeneity of logos (understood as thought and discourse) with respect to reality. Just as sight does not see sound, and hearing does not hear colours, so logos does not speak things, but words: the only possible experience is direct, first-hand experience. But this is off-limits for logos, which always represents a translation of such experience, a failed translation insofar as it proves incapable of taking the place of its object.Footnote 37 The other two arguments merely reassert the isolation of logos, showing that there is no way of confirming whether what A has communicated has been received by B as A understands it; indeed, not even A can be sure of this, given the divergence between his own perceptions and feelings at different times. An unbridgeable gulf thus separates things from thoughts and words: even assuming that being is knowable, it cannot be communicated.Footnote 38
Now that we have reached the end of this analysis, it is time to evaluate Gorgias’ treatise in all of its complexity. What are the aims of this treatise and what is its underlying meaning? Certainly, the treatise contains a fair dose of irony and provocation, both in the theses it defends and in the way in which it defends them. The problem, then, is to understand the meaning of these provocations. Scholars in the past fluctuated between two radical interpretations of Gorgias: the first dismissed his text as a mere divertissement of no real philosophical interest;Footnote 39 the second interpretation emphasized its ‘nihilism’.Footnote 40 It is all too evident, however, that both theses are one-sided, and that they fail to adequately account for the challenge launched by Gorgias. A certain playfulness, which frequently manifests itself in the author's desire to dazzle his public with bold arguments, no doubt constitutes a defining feature of Gorgias’ practice (and of the sophists’ more in general).Footnote 41 Yet this does not justify the conclusion that there is nothing of philosophical relevance in the treatise (and that the treatise is merely an example of sophistry – of arguments that are only apparently trueFootnote 42). On the contrary, we only need to think of the discussions on the verb ‘to be’ or of the problem of communicability to realize that Gorgias is raising questions of the utmost importance, which all great philosophers – from Plato to those of our own day – have felt compelled to address.Footnote 43 As for the ‘nihilist’ reading, even leaving aside the problem of what ‘nihilist’ means, it is clear that this is a doubly selective interpretation. First, it de facto only considers the first thesis – that nothing is – while the problem which Gorgias is most concerned with is the third, namely that which concerns the split between language and reality. Secondly, even if we were only to take into consideration the first part, Gorgias’ polemical target are the views of the Eleatics and the other Presocratic thinkers: what Gorgias would be denying are metaphysical entities such as Parmenides’ being or the atoms of Leucippus and Democritus. But this hardly justifies the thesis that Gorgias was a ‘nihilist’ (at most, one could argue that the supporters of the theses criticized by Gorgias – Parmenides and the other Presocratics – were nihilists).
What are more interesting, albeit not fully satisfactory, are two other interpretations which have been put forward. The first one, the ‘subjectivist’ or ‘tragic’ interpretation, was endorsed by Hegel (in his Lectures on the History of Philosophy, 1832–3) and further developed by scholars of the calibre of Eduard Zeller (fifth edition 1923), Wilhelm Nestle (1922), and Mario Untersteiner (1954). The second interpretation, which we might describe as the ‘empiricist’ interpretation, comes from the British liberal milieu and was mostly upheld in Britain by scholars ranging from George Grote (1864) to William Guthrie (1971) and Eric Dodds (1973). Unlike the nihilist interpretations, the ‘tragic’ one quite rightly emphasizes Gorgias’ main aim, namely the highlighting of the fracture between reality and human beings: to paraphrase Untersteiner, there is a tragic antithesis between our impressions and the world that surrounds us, a gap that cannot be bridged because we can only rely on language and know reality through language, and language is deceptive. The result is that each human being is confined within the prison of his or her language and does not entertain any rational (or rather ‘logical’, bearing in mind what Gorgias means by logos) relationship with reality. As far as the experience of logos is concerned, the contradictory nature of reality is unsolvable (see also 82B26 D.-K. = 32D34 L.-M.). It is only through an irrational act of volition that we can escape from this prison, so as to adapt ourselves to the multiplicity of reality. The ‘empiricist’ interpretation, by contrast, emphasizes another fundamental aspect of Gorgias’ treatise, namely the centrality of its anti-metaphysical polemic. The result is a completely different picture of Gorgias, whose attack on the Presocratics’ metaphysical doctrines is interpreted as an initial defence of the empirical world of common sense. Gorgias thus emerges as a leading exponent of the fifth-century Enlightenment, engaged in a struggle to defend human rationality. Reality exists and we can know it through our senses and via correct reasoning, with no need to yield to the abstract truths of philosophy.
No doubt, these interpretations have the merit of identifying some of the key aspects of Gorgias’ thought, from his interest in the problem of language to his focus on logical arguments. However, both of them risk assigning too much to Gorgias: for – and this is a crucial point – what authorizes us to take everything that Gorgias says as his own personal doctrine? On the contrary, what clearly emerges from a reading of his treatise is a dialectical position:Footnote 44 his arguments appear to reflect a desire to show to what absurd conclusions the theses or beliefs of his opponents lead, and not to convey any personal theories; Gorgias is arguing against, not in defence of. In other words, his treatise constitutes an apparently playful reflection on a series of far from playful problems in human life. Yet, we are not justified in turning these reflections and the arguments developed by Gorgias into a holistic theory, as the aforementioned scholars have sought to do. Gorgias’ aim is to invite his interlocutors to acknowledge the complexity of these problems, and to challenge them to come up with the most satisfactory solutions. We know nothing at all of his own answers, assuming that he had any to offer: ‘There isn't any difficulty in appreciating Gorgias’ arguments, once we see them dialectically – once, that is, we stop thinking that the only way to be serious is to be dogmatic.’Footnote 45 It is essential to clarify this point in order to appreciate Gorgias’ teaching. His whole reflection takes the form of an all-out attack against the foundationalist claims of philosophy and common sense: what Gorgias questions is not so much reality itself, as the foundationalist claim that reality possesses some invariant structures and that humans are capable of discerning and communicating such structures.Footnote 46 Whether the target is Parmenides or the ‘two-headed men’, the polemical aim is this alleged correspondence between being, thought, and language, along with everything which this thesis implies: (1) the belief that reality is something ontologically, logically, and temporally independent of us; (2) the idea that knowledge coincides with the objective apprehension of this independent structure; and (3) trust in the fact that the purpose of language is simply to convey this knowledge.
But – Gorgias asks – are things really so? Can we really speak of an isolated reality, removed from the contingencies of human culture and language? And even assuming that an independent reality exists, does knowledge simply coincide with the correspondence of thought to things? Rather, is it not the case that our opinions, prejudices, expectations, and desires condition our approach to reality? Ultimately, these are the problems that Gorgias is most concerned with. They are substantial problems.
Finally, the anti-foundationalist interpretation just outlined has the merit of explaining what is probably Gorgias’ chief contribution, namely his acknowledgement of the importance of language in human experience. As already noted, his whole treatise highlights the complexity of the linguistic phenomenon, and this awareness – as we shall see – also finds significant parallels in the other surviving works by the same author. What makes Gorgias’ reflections so interesting is the fact that he freed language (and logos more generally) from all ontological implications, all alleged metaphysical correspondences with reality: logos is not a reflection of things or the natural means by which to objectively and impartially describe reality.Footnote 47 On the contrary, Gorgias asserts the independence of discourse, with its limits and potential. As we shall see, a more in-depth investigation of this problem reveals that his theses constitute a genuine challenge to philosophy.
Two testimonies in the wake of Gorgias’ discussion: Xeniades and Lycophron
Gorgias’ theses may fruitfully be compared with the thought of another two sophists, Xeniades and Lycophron. Regrettably, little is known about them. According to the sceptic Sextus Empiricus, Xeniades claimed that ‘all things are false, that every representation and opinion is false, that everything that comes to be comes to be out of what-is-not, and everything that perishes perishes into what is not’ (81.1 D.-K. = 39D1 L.-M.). The emphasis on the theme of not-being and on the limits of human knowledge constitutes a polemical allusion to ParmenidesFootnote 48 and is reminiscent of Gorgias, if only in a distorted way, since it misinterprets the latter's underlying intentions: whereas for Gorgias the analysis of reality is preliminary to that of knowledge and language, here the movement would appear to be in the opposite direction and the outcome is a flight into nothingness. However, it is easy to dismiss this radical position: if nothing is and everything is false, then even the thesis according to which nothing is and everything is false is false.Footnote 49
More interesting is the case of Lycophron, whom Aristotle in some cases associates with Gorgias and Alcidamas. In a passage of the Physics discussing the problematic relation between unity and multiplicity, Aristotle writes:
Among the ancient thinkers, those who were later [sc. than Parmenides and Melissus] were also troubled by the question of knowing how to avoid that the same thing be at the same time one and many of them. That is why some of them suppressed the word ‘is’, like Lycophron, whereas others changed the mode of expression and said ‘the man has been whitened’ instead of ‘is white’…in order not to make the one be many by adding the word ‘is’. (83.2 D.-K. = 38D1 L.-M.)
Lycophron's aim was apparently to offer a solution to the problem of being, which had been the underlying focus of Gorgias’ polemic against Parmenides. In fact, Lycophron's suggestion is less radical than what the above passage seems to suggest: a comparison with other, later testimonies from the Neoplatonist commentators of Aristotle shows that, in order to resolve the ambiguities associated with the double use of the verb ‘to be’, Lycophron suggested that we abolish only the predicative meaning of the verb, and not the existential.Footnote 50 ‘To be’ is only used in the sense of ‘to exist’, while its copulative use is replaced by concrete verbs. This thesis, however, is not an isolated claim, but may be traced back to an empiricist theory of knowledge. Elsewhere, Aristotle reports that, according to Lycophron, knowledge is constituted of the ‘communion’ of the act of knowing and the soul (83.1 D.-K. = 38D2 L.-M.): knowledge is not limited to the statement that Socrates is white, but rather extends to the concrete, first-hand experience of Socrates’ whiteness.Footnote 51 Although this thesis, too, does not necessarily correspond with Gorgias’ positions, it may be read as following in the wake of an anti-Eleatic polemic. It also shows some interesting points of convergence with the ideas of Antisthenes, who, while famously close to Socrates, had been a pupil of Gorgias’ as well.Footnote 52 Be that as it may, without going too far in the interpretation of such fragmentary testimonies, it is important to note that, for Lycophron, the discussion on reality and being leads to the problem of language: unlike Xeniades, he appears to have grasped the meaning of Gorgias’ lesson.
Reality according to Antiphon
Antiphon was certainly among the most prominent sophists, and arguably one of the most fascinating. However, two obstacles have hampered the full appreciation of his merits, unjustly removing him from the centre stage. The first is the problem of his identity, which has added to the complexity of interpreting his ethical and political fragments. A second and just as insidious hindrance has been the prejudice according to which the sophists were only interested in the human world, which is to say rhetorical and political problems. Thus the many fragments of Antiphon's writings that deal with cosmological, biological, meteorological, geometrical, and medical topics have been neglected, in the belief that they constitute a confused mass of information collected from disparate sources. No doubt, Antiphon's analyses are largely indebted to the research conducted by natural philosophers such as Anaxagoras and Democritus or by the Hippocratic physicians. However, the conclusions drawn by Antiphon are far from obvious or banal: on the contrary, the picture of physis, of reality, that emerges from his writing is highly original and, as we shall see, constitutes the foundation for even more interesting political considerations. The case of Antiphon also shows that there is no radical break between the sophists and the Presocratic natural philosophers: in their analyses, the sophists did not overlook their predecessors’ theses.
Antiphon's main work was entitled Truth. This title was not randomly chosen, since it perfectly reflects the context in which its author sought to operate. The title is also significant in relation to Protagoras, since Antiphon's theses, particularly in the political sphere, are very much indebted to and react against the work of the sophist of Abdera. One focus of the treatise – perhaps the chief focus – was physis, which was investigated from a wide range of perspectives. The most stimulating, and best-known, section of the work concerns human nature; but the author's analysis of humankind was based on a more general analysis of reality, fragments of which also survive.
The following testimony from Aristotle helps clarify the possible meaning of Antiphon's position:
Some people think that the nature and substance of the things that are by nature is what is present first of all in each thing, without possessing configuration (arrhuthmistos) in itself, as the nature of a bed is the wood, and that of a statue the bronze. Antiphon says that evidence of this is the fact that if one were to bury a bed and the rotting could acquire the power of sending up a shoot, it would not become a bed, but wood, which shows that the arrangement in accordance with the rules of the art is merely an accidental attribute, whereas the substance is the other, which, further, persists continuously through the process.
(87B15 D.-K. = partially reproduced in 37D8 L.-M.)The above claim is far less banal than it seems. The passage establishes an opposition between what – using the Aristotelian terminology – we might call accidental characteristics, and what truly counts, namely the essence, that which subsists continuously. This opposition between convention and reality, couched in terms of the opposition between nomos and physis, was to play a decisive role in Antiphon's thought. Here it is interesting to note the way in which physis, understood as the ultimate material constituent, is presented: according to Aristotle's testimony, the term which Antiphon used to describe nature is arrythmiston, ‘without configuration’, a rare adjective that may be traced back to the Democritean tradition. Physis, then, is the unconfigured material substrate that resists all external attempts to lend it order.Footnote 53 Other fragments too – unfortunately, very short ones – confirm this picture (87B10, 12, 22–5 D.-K. = 37D9, 37, 18–21 L.-M.), suggesting that Antiphon championed an organic, dynamic, and materialist view of reality. Physis is something living and ever-changing that obeys its own rhythm, not one imposed from the outside: the natural constituents of the universe (such as the sun and planets) are the product of a chain of causal relations which do not stem from any intelligent or finalistic plan, but only from the accidental combination of the elements (87B28–32 D.-K. = 37D24–7 L.-M.).
The implications of these views are far from negligible, when examined against the background of their cultural context: Antiphon's defence of the idea of a universe governed by necessity but not providence reflects an attempt on his part to clearly distance himself from all mythical or religious explanations of reality. Moreover, he distances himself not just from religious traditions but also from most of the Presocratics, who – while emancipating themselves from the world of myth – had assigned the ultimate principle or principles a series of positive attributes usually assigned to the gods: for Antiphon, the nature of the all is not divine. Finally, from the opposite perspective, we cannot rule out a criticism of Protagoras and Gorgias, who, by placing humans at the centre of everything, had denied the priority of physis. Antiphon succeeds in the delicate task of striking a middle ground, emphasizing the centrality of nature while at the same time denying any axiological superiority to this priority: his nature, true reality, is something neutral, devoid of any meaning or value that might direct human choices. Reality is indifferent: the importance of these theses will become clear once the discussion focuses on humankind.Footnote 54
Someone who had fully realized the significance of the kind of theses put forward by Antiphon was Plato, who in the Laws – which is to say in the last years of his life, at a fair distance from the debates and cultural climate of the fifth century – felt the need to newly address the same problems in order to decry their dangers. In Book 10, the Athenian Stranger sets out to inform his two friends, the Spartan Megillus and the Cretan Clinias, about those theses which were then circulating in Athens concerning nature and the gods. Although the thinkers referred to by Plato are unnamed, it is more than likely that, among others, he was targeting Anaxagoras (who had denied the divine nature of the sun, arguing that it was only a fiery rock – a thesis at the root of all problems: 886d–e), Democritus, and even Antiphon. The last, as has been suggested, may in fact be Plato's chief polemical target.Footnote 55
The thesis put forward by the anonymous thinkers is that the universe is the necessary outcome of the accidental combination of its material constituents, which ‘moved at random, each impelled by virtue of its own inherent properties’ (889b). While the combination of necessity and chance, two apparently contrasting concepts, may seem odd at first, it reveals an interesting idea, which confirms the Antiphontic tone of the passage. What is meant by chance (tyche) is not a blind or irrational force, but an order of things which does not depend on transcendent forces or intelligent designs, but on the intrinsic features of its constituents. Once the theory has been reconstructed in these terms (it is not that far from modern theories, one may note), the reasons for Plato's opposition become clear: what we have is a first attempt to explain reality in merely materialistic and mechanistic terms, an explanation that – should it prove convincing – would entail the negation of the existence of the divine (‘the gods exist…not by nature, but by certain legal conventions’, 889e) and hence of all providentialism and finalism. This, in turn, would amount to the negation of values such as justice and virtue, which were traditionally associated with the divine order of reality. The result, in one word, is atheism; and atheism, according to Plato, is the greatest ill of all, on account of its political consequences: with the disappearance of the gods, the values of justice and morality safeguarded by the gods also vanish (‘there is no natural standard of justice at all. On the contrary, men are always wrangling about their moral standards and altering them’, 889e). The only remaining law, then, is that of violence: ‘everything one can get away with by force is absolutely justified’; ‘the true [note the importance of this term] natural life is essentially nothing but a life of conquest over others, not one of service to your neighbour as the law enjoins’; and this justifies those acts of impiety and subversion which have driven Athens and the Greek world to the verge of the abyss (890a–b; cf. 715a–716c).
As we shall see in the following chapters, it is most unlikely that Antiphon advocated violence: the link between an independent conception of nature, atheism, and political violence is something inferred by Plato, who finds in this connection further confirmation of his view that the sophists’ teaching is a social threat. Still, the fact remains that Antiphon's theses posed a radical challenge to intellectual traditions that were well rooted in the Greek world. And, in this respect, Antiphon proves himself to be a fine sophist.
From physis to logos: Presocratics and sophists
In the light of the analyses conducted thus far, it is possible to redefine the sophists’ position vis-à-vis the Presocratic philosophers. No less simplistic than the claim that the Presocratics focused only on the natural world and not on the human world is the thesis that the sophists had no interest in physis and only focused on humanity. Rather, what the sophists appear to have polemically engaged with is the fascination with what is obscure, with the hidden nature of things.Footnote 56 However, physis as such remains the starting point of all enquiries. To be more precise, reality remains the central problem that cannot be overlooked: the common denominator in all these disparate theories, often developed in polemical contrast to one another, is the acknowledgement of the problematic nature of reality.Footnote 57
And yet, the sophists are responsible for a fundamental turn in the history of philosophy, a turn the importance of which can hardly be ignored: a shift of focus from nature to the human world. Of course, as has been noted, this does not mean that the Presocratics had not focused on the human world; but they had done so starting from their study of physis, by considering human beings as part of the whole. The sophists adopted a completely new perspective, by setting out from the belief that things must be turned round, that it is reductive to consider humans simply as a part of the whole. On the contrary, in their view it is necessary to set out from human beings and their uniqueness with respect to other entities. In other words, the sophists follow in the trail of the Presocratic philosophical tradition and continue to investigate problems related to nature, the city, and humankind, but following an opposite hierarchy, based on a decisive philosophical intuition that no subsequent thinkers could afford to ignore: the idea that the relation between reality and human beings is problematic and cannot be taken for granted, but must rather be constructed. And it is on the basis of this acknowledgement that the sophists discussed human beings and their problems: for if nature in itself is ambiguous, neutral, or devoid of meaning, one must turn elsewhere in order to discover the meaning of humanity's experience and life. The attention shifts from cosmology to epistemology, from the study of reality in itself to that of how we can know reality and relate to it – from physis to logos.
