As the father of Western philosophy, who transformed Greek thought with his questioning insights into life and ethics, Socrates (470-399 bc) was a powerful inspiration - and major irritant - to the Athenians of his day. After his trial and execution on charges of heresy and the corruption of young minds, his greatest pupil Plato (c. 427-347 bc) wrote a series of dialogues as an act of homage. Lesley Brown is Centenary Fellow in Philosophy at Somerville College, Oxford, and the author of numerous articles and book chapters on Plato and Aristotle.