  Prodicus’ position on religion was discussed earlier. Apart from it he is best known for his insistence on the correct use of language (Plato, Euthydemus 277e), in particular fine discriminations of the senses of near-synonyms, a topic in which he seems to have specialised. Plato gives numerous examples in the Protagoras (especially 337a–c) and in other dialogues (for details see DK 84A13–18), and Socrates says (Cratylus 384b) that he has attended Prodicus’ ‘one-drachma’ lecture on names, but was unfortunately unable to afford the full course, for which the fee was fifty drachmas (a drachma being a day’s wage for a skilled craftsman at this period). He is reported as having had some interest in natural philosophy, including astronomy (DK 84AI (Suda), A5 (Aristophanes) and B3 (Galen)), and as having applied his linguistic theory to medical terminology (DK 84B4 (Galen)). All that has survived of his writings is a paraphrase by Xenophon (Memorabilia II.1.21–34) of his moral fable of the choice of Heracles between Virtue and Vice. In this story Heracles is approached at a cross-road by two female figures representing Virtue and Vice, each of whom tries to persuade him to follow her by describing the attractions of a life with her. Both base their appeal on pleasure, Vice stressing the meretricious allurements of the voluptuous life, while Virtue offers the genuine and lasting pleasures of the life of honesty and sobriety, including good reputation and the favor of the gods, an appeal which wins the day. In contrast to his radical views on religion, the moral stance expressed here is thoroughly conventional. (Mayhew 2011 xiv-xvii gives a useful summary of the basics of Prodicus’ treatment of language.)