Professor Bernard Williams is this country's greatest living philosopher. In his new book, Truth and Truthfulness, he tackles one of the most pervasive paradoxes of our times: while the concept of truth is often regarded with suspicion, there is still an intense commitment to the idea of truthfulness. Professor Williams will be online at 3pm on Tuesday November 12th to discuss these concepts and others which you care to raise on matters philosophical, political and academic. Post your questions now.