PIRRHONISM
Pyrrhonism is the school that took its name from the sceptical doctrine of Pyrrho of Elis (c. 360–270 BC). It may be summed up in the thesis that nothing can be known, so that one must doubt everything and refrain from any judgment on any object. The heir (to withhold assent) and the Greek terms that denote this attitude are the ones used today (cf. Diog. Laer., Prooem., 16; IX, 76).
Immediate disciples of Pyrrho (who transmitted his thought only orally) were Philo of Athens (date uncertain), Nausiphanes of Teos (b. c. 360 BC), and the celebrated Timon of Phlius (c. 320–230 BC), the true torch-bearer of scepticism, who in the burlesque poems called *Silloí* derided the dogmatic philosophers and extolled his master, and in the *Indálmoi* reaffirmed the Pyrrhonian conception. Closely bound up with the epistemological outlook in Timon, as in Pyrrho, is the ethical ideal of ataraxia, i.e. the soul’s freedom from disturbance. Indeed, the withholding of every theoretical judgment leads, according to the sceptics, to regarding all things as indifferent in the practical sphere. *Ataraxía* is a consequence and almost a shadow of *epoché* (Diog. Laer., IX, 107). With Timon one may say that the original Pyrrhonian school comes to an end; sceptical thought flourishes instead in a less radical form in the Middle and New Academy. The full Pyrrhonism was taken up again by the new sceptical school (from the last days of the Republic to the 2nd cent. AD): its first representative (or at least the first known to us) was Aenesidemus of Cnossos (c. the Ciceronian age), author of *Pyrrhôneioi lógoi* (Pyrrhonian Discourses) in eight books, of *Hypotypṓseis eis tà Pyrrhôneia* (Outlines of Pyrrhonian Theory) and of other works, and particularly notable for having set forth the ten fundamental arguments (τρόποι, i.e. ‘modes’ of *epoché*: cf. Sextus Empiricus, *Pyrrh. Hypot.*, I, 36) of scepticism. Later the school was represented by Agrippa (1st cent. AD), who reduced the grounds of universal doubt to five tropes instead of ten (ibid., I, 164), and then by the physician Sextus Empiricus (v.), whose philosophical writings contain a full polemical presentation of Pyrrhonism. In the Middle Ages Pyrrhonism was scarcely known at all. Rediscovered in the Renaissance, it exercised great influence on various thinkers (among them M. de Montaigne and P. Charron in the 16th cent. and P. Bayle in the 17th), and the word was used as a synonym for scepticism (v.).