  On the other side of the debate, as we have seen, we have Protagoras’ contention in the Great Speech that law and morality are themselves natural developments, necessary for human survival and the growth of civilization. Protagoras agrees with Glaucon that moral and legal conventions arise ultimately from the need for cooperation in a hostile world, but rejects the latter’s Thrasymachean egoism, with its implication that morality is merely a second-best, to be rejected if circumstances allow the individual to pursue his natural goal of unrestrained self-interest. Morality, for Protagoras, consists in justice and self-restraint, dispositions which involve the replacement of Thrasymachean egoism by genuine regard for others as of equal moral status with oneself, and the crucial lesson of the Great Speech is that those dispositions, so far from requiring the stunting of human nature as Glaucon maintains, in fact constitute the perfection of that nature. The idea that law and morality arise from the exigencies of human nature is also found in some fragments of Democritus and in the so-called ‘Anonymous Iamblichi’ (DK 89), a fragmentary text from the late fifth or early fourth century BCE preserved by the neo-Platonist Iamblichus (third–fourth century CE: see Taylor 2007). This defence of the authority of nomos rests on the idea that nomos itself, in the sense of legal and moral convention, arises from phusis. A different, though related, defence of nomos assumes a distinction between on the one hand the moral and legal conventions of particular societies, assumed to be the product of human agreement, and on the other certain fundamental moral norms, alleged to be common to all societies, whose origin is to be traced, not to any agreement, but to the original constitution of human nature, traditionally attributed to the creation of humans by the gods; these norms were generally agreed to include the obligations to respect one’s parents and to worship the gods. The conception of natural or unwritten law is frequently appealed to in oratory and drama, notably Sophocles’ Antigone (see Guthrie 1969 pp. 77–9, 117–31 and Taylor 2008); one of its most extended expressions occurs in Xenophon’s Memorabilia IV.4.14–25, where in conversation with Socrates the sophist Hippias is represented as saying that since the unwritten laws are common to all countries, they cannot have arisen from agreement among humans who spoke different languages, and as being persuaded by Socrates that breach of such laws inevitably leads to bad consequences, thus guaranteeing the rationality of this divine legislation. There is, then, no uniform sophistic position in the nomos-phusis debate; different sophists, or associates of sophists, are found among the disputants on either side.