Autonomy is the central idea of modern practical philosophy. Understood as self-legislation, autonomy seems to require that the validity of norms depends on recognition, namely, that their addressees, being autonomous agents, recognize these norms to be valid. But, how can one be bound by norms whose validity depends on their being recognized as valid by their addressees? The questions of how autonomous morality and, on this basis, the authoritative character of law can be understood present persistent puzzles that have been widely discussed, but still await a satisfactory solution. This book...