    Atheism is more overt in the account of the origin of religion in a passage from a play called Sisyphus (DK 88B25), quoted by Sextus (Against the Mathematicians IX.54), attributed by DK and others on the authority of Sextus to the Athenian poet and oligarchic politician Critias, but now more usually thought to be by Euripides. The speaker (apparently Sisyphus himself) begins with the picture of primitive human origins familiar from Protagoras’ Great Speech: at first human life was bestial, unregulated by law, so humans invented laws to restrain mutual aggression. But since legal sanctions were effective only when the crime was discovered, someone ‘stalwart and wise in his mind’ invented the fiction that there are gods who live in the heavens, who see everything and punish evil-doing, even when it is secret. Atheism is explicit; the stalwart and wise man ‘concealed the truth with a false account’ (line 26). Of course atheism expressed by a character in a play cannot be directly attributed to the author, whoever he was; this is merely one of the expressions in fifth-century drama of a wide range of attitudes to religion, ranging from outright atheism (e.g., Euripides Fragments 7, 286, ‘Does then anyone say there are gods in heaven? There are not, there are not, if a man is willing not to give foolish credence to the ancient story’) to pious declaration of faith (Euripides Fragments 8, 912b, ‘See, all you who think the gods do not exist, how you are doubly in error with your poor judgment. They exist indeed, they exist’). The significance of the Sisyphus fragment is rather as further evidence of the fact that in the late fifth century the rationalistic approach to the natural world, including human nature, provided the intellectual foundation of a range of views hostile to traditional religion, including explicit atheism. From Protagoras himself we have a first-person declaration, not of atheism, but of agnosticism, in what was apparently the opening of his work On the Gods: ‘Concerning the gods I am not able to know either that they exist or that they do not exist or what their nature is; for there are many things which prevent one from knowing, both the unclarity (sc. of the subject) and the short span of human life’ (DK 80B4). According to some sources the outrage occasioned by this work led to his books being publicly burned and his being forced to flee from Athens to escape prosecution, and he is said by some to have drowned while trying to escape by sea (DK 80A1–4, 12). That story suggests that he was seen as a threat to traditional religion, much as Anaxagoras (and later Socrates) was, but the evidence of Plato’s Meno 91e (see above) gives an altogether different picture, since in that passage Socrates describes him as having had an unblemished reputation during forty years of activity as a sophist, a reputation, moreover, which has lasted from his death till the present day, i.e., till the dramatic date of the dialogue in the last few years of the century. Protagoras’ avowed agnosticism did not, then, provoke public outrage or even bring him into ill-repute, and it is worth considering why not. The answer may lie in his social relativism on matters of morality (see above); it is probable that among the things which ‘seem right and fine for each city’ and which therefore ‘are so for that city so long as it maintains them’ (Theaetetus 167c) are the prescriptions that it is right to honour the gods by the traditional observances. (The verb nomizein, here translated ‘maintain’, is regularly used to apply, among other things, both to religious belief and to ritual practice: the wording of the accusation against Socrates, that ‘he does not nomizei the gods whom the city nomizei’ implies that he neither believes in nor worships the gods of the city.) It is probable, then, that Protagoras was supportive of traditional religious practice, while the wording of his proclamation of agnosticism does not even offer a direct challenge to conventional belief. He cannot know whether or not the gods exist or what they are like; this presumably (though in the light of Protagorean subjectivism the inference is not as secure as it would otherwise be) implies that no-one can know these things, but lack of knowledge is no bar to belief, particularly if that belief is socially useful, as Protagoras probably thought it was. Overall, it is likely that Protagoras’ position on religious belief and practice was as conservative as his general social and moral views. If Xenophon’s portrayal of Hippias’ moral stance (see above) is historically accurate, then he held a deeply traditional view of the gods as authors of the unwritten law.