The scale of my debt is almost unfathomable; broad and deep and wide. For it is the direct inverse of the seemingly limitless assistance friends, colleagues and well-wishers have provided over the past months and years. Their help has been active and passive, sustained, vital, and willingly, generously, provided. Daunted, and doomed never to give full and proper acknowledgement to all whom I should, I would like sincerely to thank Wyn Bowen, Bob Folely and Kate Utting for giving me essential time and space in which to research and write; Nicola Ramsey, Ellie Bush and their colleagues at Edinburgh University Press for their professionalism, efficiency and patience; Neil Curtis for his attentive copyediting; Sebastian Elischer and Matthijs Bogaards for helping me better to understand Levitsky and Way; the reviewers, anonymous and not, for their useful feedback on the proposal and earlier drafts; Andrew Stewart, Ashley Jackson and Ken Payne for their sustained encouragement and interest when they had far more pressing calls on their time; and my family for their questions, enquiries, stoicism and reassurance. Finally, I should like to give special thanks to Sophie Hague. Yet again, she has improved the typescript beyond measure, put up with more, and done so always and unhesitatingly. It is to her that this book is dedicated, with love and gratitude.