This monograph opens with an examination of the aid industry and the claims of leading practitioners that the industry is experiencing a crisis of confidence due to an absence of clear moral guidelines. The book then undertakes a critical review of the leading philosophical accounts of the duty to aid, including the narrow, instructive accounts in the writings of John Rawls and Peter Singer, and broad, disruptive accounts in the writings of Onora O'Neill and Amartya Sen. Through an elaboration of the elements of interconnection, responsible action, inclusive engagement, and accumulative...