This book has its origin in the Carlyle Lectures delivered at Oxford University in Hilary Term 2005. I would like to thank George Garnett and the other members of the Carlyle Committee for honouring me with their invitation to give the lectures, and the Warden and Fellows of All Souls College for extending to me their hospitality for the period concerned. I benefited greatly from discussing matters arising from the lectures with members of the audience during my time in Oxford. In composing a work of this kind, I have inevitably drawn on the learning of a large number of scholars who have written extensively and expertly in aspects of my subject. In addition, colleagues and friends have generously read my work or parts of it in draft and given me encouragement and advice. They include Margaret Atkins, Tim Blanning, Anthony Bowen, Peter Brown, Myles Burnyeat, Luigi Capogrossi Colognesi, Patricia Crone, John Crook, Michael Frede, Raymond Geuss, Richard Gordon, Verity Harte, Caroline Humfress, David Ibbetson, Melissa Lane, Geoffrey Lloyd, John Marenbon, Dieter Nörr, Michael O'Brien, Glenn Olsen, Christopher Rowland, Magnus Ryan, Malcolm Schofield, David Sedley, Quentin Skinner, Gareth Stedman Jones, John Thompson, Robert Tombs and Frank Walbank. I owe a special debt of gratitude to Raymond Geuss, Richard Gordon and Caroline Humfress for raising my sights and lifting my spirits. Niketas Siniossoglou has given me invaluable assistance in the closing stages. My family has been as usual tolerant, patient and supportive.

There were six lectures in the first instance.