After the Versailles Treaty it was to become a commonplace that simple liberal nostrums such as ‘self-determination’ were ill-adjusted to complex historical realities. But whatever the complications of Silesia or the Sudetenland, they paled by comparison with the problem facing Secretary of State Montagu in his attempt to devise a system of ‘responsible’ self-government for India. The task involved devising a constitution for an entire subcontinent, an extraordinarily diverse slice of humanity, divided along lines of religion, ethnicity, caste and class.