As the Presocratic philosophers bow out and Plato arrives to direct the next drama in the series, the Sophists make an astounding final act. All singing, all dancing, they ask society to question its raison d'être, its political beliefs, its moral values, its religious beliefs, its educational system, its legal codes, and its codes of etiquette. They draw attention to the power of the media and ask us to consider whether, without the media, there would be any truth at all. The antagonism that they generate, as portrayed by the Socrates imagined in Plato's dialogues, starts the ball rolling for some of the most exacting philosophical endeavours the world has ever seen.

Presocratic Philosophy: A Very Short Introduction (2004) - Ch. 7 : Spin doctors of the 5th century