I owe my thanks to many people who, in varied ways, encouraged and assisted me with this book over the years. I wish to thank Simon Critchley and Keith Ansell Pearson for having asked me to write this book; John Sallis, Thomas Sheehan, Robert Bernasconi, Françoise Dastur, Michel Haar, Andrew Benjamin and Christine Battersby for their unfailing support; and John Protevi, Peter Poellner and Peter Osborne for their scholarly and critical advice. But most of all, I would like to express my deepest gratitude to Simon Sparks for his invaluable editorial and translating skills, his philosophical insights and ingeniosity, as well as his unlimited generosity.