Until recently, Sextus Empiricus's Outlines of Pyrrhonism had been little read in modern times, and less understood. But in the last quarter-century, a revival of interest in later Greek philosophy in general, and scepticism in particular, has seen it largely restored to its rightful place as one of the most influential texts in the entire history of Western philosophy. In this chapter, I shall concentrate upon producing my own outline of its contents; but I shall also seek to put it in its proper place in the Greek sceptical tradition, as well as within the longer tradition of Western epistemology, upon which, principally through the mediation of Descartes, it has exercised an incalculable, if often largely obscured, influence.

Sextus the empiricist

The sobriquet empeirikos indicates in all probability that Sextus was a member of the empirical school of medicine, which flourished from the middle of the third century BCE at least until the third century CE. We cannot date his career with any certainty; but it must have unfolded in the late second or early third centuries CE. He is mentioned in Diogenes Läertius's Lives of the Philosophers, in the list of prominent Pyrrhonian philosophers (DL 9.116); but we do not know precisely when Diogenes wrote (although, again, the third century seems likely), and nor can we date those philosophers said by Diogenes to be his teacher and his pupil (Herodotus of Tarsus and Saturninus).