One of the best-known fragments of a lost Greek drama is Critias' fr. 43F19 Snell, an extended rhesis from the play Sisyphus in which the protagonist narrates how once upon a time human life was squalid, brutal, and anarchistic; as a remedy men devised Law and Justice; this expedient served to check open wrongdoing but did not hinder secret crimes; then some very clever man hit upon the idea of inventing gods and the notion of divine retribution; thus secret criminality was stopped by fear of the gods.
The prevalent understanding of Critias' motives is largely determined by the commonest interpretation of this fragment. Some authorities think the notion of divine justice as merely a human device designed to serve a socially utilitarian purpose is Critias' own invention; others regard this passage as wholly or in part a réchauffé of the ideas of others, such as Protagoras, Democritus, or Diagoras of Rhodes. With few exceptions, it has until recently been thought that Critias was, if not a sophist himself, at least a cynical disciple of Machtpolitik who differed from similar thinkers such as Thrasymachus and Callicles only in that he translated ideas similar to those these figures are made to express in the pages of Plato into brutal political action.
A handful of authorities have dissented from this view on the grounds that it is dangerous to attribute to a playwright sentiments placed in the mouths of his stage-characters (although to be sure, as we shall see, the theory that the views expressed in the fragment were the poet's own has ostensible ancient authority in the doxographic tradition). Recently the prevalent interpretation of fr. 19 Sn. has been subjected to additional criticism in two articles by German writers that may well be harbingers of a major reappraisal – long overdue, in the present writer's opinion – of Critias' beliefs.