INTRODUCTION

Scepticism was first formulated and endorsed by two different schools or groups, the Academics in the third century BC and the Pyrrhonist sceptics in the first century BC. It is, properly speaking, a product of the Hellenistic period. However, it is sometimes assumed that earlier philosophy was marked by a naïve complacency about whether knowledge is really possible. According to this view, philosophers in the classical period may have asked what knowledge is, but not whether knowledge is even possible at all.

This is mistaken for two reasons. First, earlier thinkers anticipated many of the arguments employed by Hellenistic sceptics. “Sceptical” arguments were in the air from the period of the Presocratics on, although not in the form of a well-defined position, but in the form of certain loosely related ideas and arguments. And they did not go unnoticed; the potentially destructive force of these “sceptical” arguments was appreciated by philosophers like Plato, Aristotle, and Democritus. Their formulation of the problems confronting the possibility of knowledge, together with their responses and attempts at defusing those problems, would inspire and anticipate many of the debates between sceptics and their opponents in the Hellenistic period.