Ever since Descartes identified the first task of philosophy as the defeat of scepticism, the challenge posed by scepticism has remained a central problem for epistemology. Neil Gascoigne introduces the sceptical arguments and methods of the canonical philosophers from Sextus Empiricus's Pyrrhonism to Hume before examining the so-called "therapeutic" approaches to scepticism and arguments for scepticism's apparent intractability.

Gascoigne explores the challenge to epistemology itself and considers two contemporary responses: the turn against foundationalist epistemology in favour of more naturalistic conceptions of inquiry, and the resistance to this response by non-naturalistically inclined philosophers. This contextualization of the sceptical debate gives students a better appreciation of the methodological importance of sceptical reasoning, an analytic understanding of the structure of sceptical arguments (including an assessment of whether the theoretical burden lies with the sceptic or anti-sceptic), and an awareness of the significance of scepticism for other areas of philosophical inquiry.