Sextus Empiricus
c. 2nd – 3rd century CE · Unknown; likely Alexandria or Rome
A physician whose handbooks preserve the arguments of ancient Pyrrhonian scepticism, and shaped modern philosophy when they were rediscovered.
Key ideas
Sextus collected the sceptics' 'modes', standard patterns of argument for suspending judgement. The best known, credited to Agrippa, says that any attempt to justify a belief must either go on forever, stop at an assumption, or argue in a circle. This trilemma is still the starting point for debates about foundationalism and skepticism.
He presented scepticism not as a doctrine that nothing can be known, which would itself be a claim to know, but as an ability to set appearances against each other until judgement is suspended, followed by tranquillity, as a shadow follows a body.
Life, briefly
Almost nothing is known about his life except that he was a doctor of the 'Empiric' school of medicine, which is where his surname comes from. Latin translations of his works in the 1560s helped spark the sceptical crisis to which René Descartes responded.
Major works
- Outlines of Pyrrhonism
- Against the Mathematicians (Adversus Mathematicos)
Schools of thought
Appears in
Further reading
- EncyclopediaStanford Encyclopedia of Philosophy: Sextus Empiricus
- WikipediaSextus Empiricus