1 Calculating Compassion: Accounting for Some Categorical Practices in International Development 1 Maia Green A final version of this paper is published in David Mosse (ed) Adventures in Aidland: The Anthropology of Professionals in International Development , Oxford, Berghahn. Introduction This chapter explores the practice of policy making in international development though an examination of the work that goes into the establishment and dissemination of core categories of the development imaginary – the targets of legitimate intervention. Following some key moments in the social life of a development category, that of children affected by HIV and AIDS, I show how policy coalitions and the relations which sustain them comprise ‘communities of practice’ (Wenger 1998) which come into being around particular objects of development. It is through these personal and professional networks, and the practices and institutions which sustain them, that the categories of international development practice become salient. 2 As communities of practice organized around categorical positions, policy communities seek to affect development practice in order to enhance the significance of the categories they promote. This is achieved through fostering relationships, the production of documentation and the positioning of persons, documents and the categories they support at points of influence within the international development system. Just as development documents are claimed by those who spend their lives working on them to be ‘living documents’, multiply authored and endlessly reworked, development categories are living categories. Not only are they (like the documents in which they appear)