Richard Bett presents a ground-breaking study of Pyrrho of Elis, the supposed originator of Greek scepticism, active around 300 BC. Against the standard scholarly view, Bett argues that Pyrrho's philosophy was significantly different from the long later tradition which called itself 'Pyrrhonism', and that this was not a monolithic tradition but had two distinct phases. Bett also investigates the origins and antecedents of Pyrrho's ideas. The result is the firstcomprehensive picture of this key figure in the development of ancient philosophy.