¹ On the importance and limits of the interpretations put forward by Hegel and English liberals, see Kerferd 1981a: 4–14; on Nietzsche, see Consigny 1994.

² Popper 1971: 162. One author who describes the contemporary age as a ‘Third Sophistic’ is Vitanza 1997; see also Fowler 2014. See too Rorty 1979: 157. The expression ‘Second Sophistic’ is used to describe the revival in the Imperial age of certain elements introduced by the sophists in the fifth century bc. The focus in this case was on rhetorical and literary themes, while the more strictly philosophical aspect was largely overlooked. For this reason, I will not be discussing the phenomenon here (for an interesting attempt to link the fifth-century sophistic and the Second Sophistic, see Cassin 1995).

³ It may be worth noting that, in the surviving testimonies, the only sophist to describe himself as such is Protagoras in the Platonic dialogue that bears his name (Protagoras, 317b = 80A5 D.-K. = 31P13a L.-M.).

⁴ Kerferd 1981a.

⁵ Naturally, this list, while perfectly reasonable, is not decisive. To give just one example of how difficult it is to precisely identify the sophists: in his writings, Aristotle applies this label to four authors alone, namely Lycophron, Polyeidos, Bryson, and Aristippus. Only the first of these is reckoned among the sophists today (Polyeidos appears to have been a poet and literary critic, while Bryson and Aristippus are possibly to be associated with the milieu of the Socratic schools). All four are called sophists in relation to language and ethico-political issues, which – as we shall see – constituted the privileged object of reflection for the sophists.

⁶ On the meaning of sophistês and its history, see the following analyses: Untersteiner 1949–62: i.xvi–xxiii; Guthrie 1971: 27–35; and Kerferd 1981a: 24–41. An alternative reconstruction is put forward by Edmunds 2006, according to whom sophistês only entered into use as a technical term in the fourth century bc, whereas in the fifth it described a gamut of intellectual figures, including soothsayers, dithyrambic poets, scientists, and orators. This study confirms the importance played by Plato and Aristotle in the definition of the sophists’ identity; still, it does not rule out that by the fifth century the term ‘sophist’ had already come to be associated with the practice of teaching, which is perhaps the most distinguishing feature of the sophists’ activity; on this, see also Tell 2011.

⁷ Blank 1985.

⁸ To get an idea of the extent of the sophists’ travels, see the profiles in Appendix 1. It is important to bear in mind that many sophists also travelled for political reasons, acting as ambassadors of their cities: see esp. Plato, Hippias, 282b–c, on Gorgias, Prodicus, and Hippias. One may recall Gorgias’ famous embassy to Athens in 427 bc. Similar embassies have been suggested in relation to Thrasymachus, albeit on less certain grounds: see White 1995 and Yunis 1997. It is also worth mentioning Antiphon's famous embassy to Sparta after the coup of 411 bc – assuming that the hypothesis that identifies the sophist with the orator by that name is correct.

⁹ See Fait 2007: xl–xliv.

¹⁰ Lloyd 1979.

¹¹ The sophists’ ambition explains why their activity entailed not only private lessons but also public performances (epideixis): see Guthrie 1971: 41–4. Privately, the teacher was chiefly concerned with presenting certain argumentative schemes that the pupil could then make use of for his own benefit (see Natali 1986; it is possible that these arguments were subsequently brought together to form genuine discourses that might serve as a model for students). Public performance was a privileged avenue for sophists to promote themselves and their wisdom even before an extensive audience (for instance, during solemn celebrations such as the Olympic Games). For a vivid description of these performances, see Lloyd 1987: 79–102; for analyses of the possible circulation of these discourses in written form, see O'Sullivan 1996 and Thomas 2003. While bearing this distinction in mind, we should not overemphasize the break between public and private, since even the teaching of arguments could take place in open contexts: this is the case, for instance, in Plato's Euthydemus, where Euthydemus and Dionysodorus, mocking their interlocutors, present argumentative schemes that their pupils can apply to new cases. The truly enduring feature of the sophists’ activity is its agonistic-competitive character. Interesting points on the historical and cultural context may also be found in Soverini 1998.

¹² Significantly, in the first book of the Metaphysics, the treatise that is usually regarded as the first history of philosophy, no mention is made of the sophists, whereas their theses are widely discussed in the treatises of the Organon – in particular, in the Sophistical Refutations. On Aristotle and the sophists, see the observations made by Classen 1981, who notes that, although Aristotle does not regard the sophists as genuine philosophers, he does not simply despise them either. Aristotle's interpretation was especially influential among the great Latin orators, from Cicero to Quintilian, who only dealt with the sophists in relation to their rhetorical studies. Among modern scholars, a similar interpretation has been upheld by Gomperz 1912 and, more recently, in a completely different context, by several American scholars interested in a reassessment of rhetoric (see e.g. Schiappa 1991 on Protagoras and Consigny 2001 on Gorgias). Along much the same lines, Michael Gagarin, who is the author of some of the most enlightening contributions on the ancient sophists, has stressed the central importance of logos (which can mean ‘word’, ‘speech’, or ‘reason’) as the cornerstone of the sophists’ investigations (see, for example, Gagarin 2002 and 2008). While the importance assigned to logos is indisputable, it does not imply a lack of interest in ethical and political issues, as we shall see.

¹³ Goldhill 1986: 222–7.

¹⁴ The thinly veiled allusion here is to Protagoras, who promised to ‘make the weaker argument the stronger’ (80B6b D.-K.): a provocative claim in its ambiguity, given that ‘weaker’ might also mean less just.

¹⁵ Besides, the sophists had touched upon this theme too in a provocative fashion: see Antiphon 87B44B, 5.4-8 D.-K. = 37D38 L.-M.

¹⁶ Paci 1957: 126.

¹⁷ See now Corey 2015.

¹⁸ Significantly enough, aside from a few exceptions, the dominant view today is precisely that the sophists’ activity entailed an engagement with ontological and political issues. This may be inferred from the most authoritative studies on the subject, which, while disagreeing on many points, agree at least on this one – from Untersteiner 1954 (first published in Italian 1949) to Kerferd 1981a, from Guthrie 1971 (first published 1969) to Cassin 1995.

¹⁹ Gagarin 2008: 23.