Introduction

The implication of the all-or-nothing premise introduces wider Platonic themes which centre around the status of the elenctic method. The impasse to inquiry, together with the impossibility of false belief puts the Socratic elenctic method in contradiction with itself. Plato understands Parmenides as presenting a challenge to the way that language had until his time be understood to work, and that such a view could be defended needs some consideration. In the case of the sophists, Protagoras’ Man-Measure argument is the source of their acclaimed epistemological relativism which is the target of Plato’s antagonism and the strength upon which their tenet that ‘anyone can rightfully argue for any claim’ rests. The Sophistic challenge seems thus to entail the eristic method and the epistemology it depends on. The chapter also presents an overview of the key concepts discussed in this book.