Virtually nothing is known about the life of Sextus Empiricus. He was a doctor and, as his name implies, a member of the Empiric school of medicine. He probably lived in the second century ce. His importance in the history of philosophy lies in the fact that he is the only ancient Greek sceptic whose complete works survive. Specifically, he belonged to the Pyrrhonist sceptical tradition, taking its inspiration from Pyrrho of Elis (c.360-c.270 bce), but organized as a systematic philosophical outlook in the early first century bce by Aenesidemus of Cnossos. Sextus' surviving works are as follows: (i) Outlines of Pyrrhonism (hereafter PH, the initials of the title in Greek), which offers a general account of scepticism in the first book and, in the remaining two books, a critical assessment of non-sceptics' views in logic, physics and ethics, the standard areas of philosophy in the Hellenistic period; (ii) a work in six books criticizing the pretensions to theoretical knowledge by experts in various specialized fields such as rhetoric, mathematics and astrology, called Against the Professors (Adversus mathematicos in Latin, hence the standard abbreviation M); (iii) an incomplete work that originally covered the same ground as PH, but at much greater length; the surviving parts are Against the Logicians in two books, Against the Physicists in two books and Against the Ethicists in one book.