In this chapter I offer an account of only one special form of scepticism, the philosophical activity and view known as Pyrrhonism. Moreover, the account I give is of Pyrrhonism as represented by Sextus Empiricus in his work Outlines of Pyrrhonism (1933). Thus, my treatment of scepticism might seem to be doubly narrow. However, there are some reasons for not attempting a more inclusive picture. One is that such presentations can already be found in textbooks on Greek philosophy, in philosophical and other reference books, and in a number of monographs devoted solely to scepticism. But there is a more compelling reason as well.