Aim of the volume is to offer a detailed and exhaustive presentation of the sophistic movement. A point which all the Sophists, in spite of many other divergences, appear to share is the view that there is a tension between us and the sourronding reality: this is particularly evident in Protagoras' famous 'Man Measure' fragment and in Gorgias' tripartite thesis, but not less significant are the views of other sophists such as Antiphon or Lycophron. And the same assumption is the basis for many of the most important theories endorsed by the sophists from the new insistence on language as what creates the world (and not what has merely to mirror reality) to the realist account of justice as what depend on our decisions (which can be taken as a first anticipation of conventionalism and positivism). The volume also investigates problems which have not yet received due attention, most notably in the field of ethics, and concludes with an account of what the sophists said of the gods, probably the field in which these thinkers were more provocative.