Jonathan Barnes was educated at the City of London School and at Balliol College. For 25 years he taught at Oxford, being a Fellow first of Oriel and then of Balliol. He then spent eight years at the University of Geneva, before becoming Professor of Ancient Philosophy at the Sorbonne. He is a Fellow of the British Academy, and of the American Academy of Arts and Sciences. His many publications include The Ontological Argument (Macmillan, 1972); Aristotle's Posterior Analytics (Clarendon Press, 2nd edition 1993); Aristotle (OUP, 1982); The Complete Works of Aristotle (Princeton UP, 1984); and Truth, etc. (Clarendon Press, 2007); with J. Annas, The Modes of Scepticism (CUP, 1985); Early Greek Philosophy (Penguin, 1987); The Toils of Scepticism (CUP, 1990); The Cambridge Companion to Aristotle (CUP, 1995); and Porphyry: Introduction (Clarendon Press, 2003). He lives in France.