This project studies the relationship between classical political economy and the British East India Company's opium trade in South Asia to explain the remaking of the British Empire as an empire of free trade. Beginning with the loss of the American colonies in 1783, it traces the contingent evolution of British economic thought amidst the political turmoil of the age of revolutions, in particular the ascendance of a utilitarian interpretation of political economy within the administration of the East India Company. Focusing on the interplay between these emerging doctrines and the development of the Company's opium business, it attempts to understand the transformation of customary understandings of the drug as a luxury commodity, subject to strict policies of regulation and limited production, to a liberal commodity, in which its social utility would be determined solely by the price it fetched on the open market. By explaining the rise of opium as the key commodity in the political economy of South and East Asia between the late eighteenth century and the outbreak of the First Opium War in 1839, this project emphasizes the moral ambiguities of emergent conceptions of exchange value, using opium as a limit case through which to understand political contestation over the capitalist commodity form in the context of British imperial crisis, reinvention, and expansion. Ultimately, it aims to provide a new interpretation of the rise of liberal imperialism out of the Enlightenment critique of mercantilist empire.