In varying ways, scholars working in the discipline of International Studies have found themselves, often implicitly, wrestling with the question of what should and should not count as harm and the implications of this for wider social life. Core to this tension is the way in which the discipline can be understood as lying between the explanatory concerns of a social science and a normative endeavour concerned with the reduction or mitigation of avoidable harm. This thesis argues that this tension results in an understanding of the problem of harm as a particular problem-field defined by a set of questions that motivate various aspects of theoretical activity. However, it attempts to address the problem of harm as a whole through the lens of Frankfurt School Critical Theory. In doing so, it aims to draw out the implications of the problem of harm for the discipline of International Studies and social science more broadly. The importance accorded to the problem of harm in Critical Theory is the source of considerable problems for an understanding of how social science might operate due to the way that normative concern serves to overwhelm attempts at explanation. This thesis considers Linklater’s sociology of harm conventions a way of rebalancing this equation such that some practical conclusions may be drawn. However, the theoretical underpinnings of this project in the process sociology of Norbert Elias serve to preclude sufficient engagement with normative questions. A reconstruction of the sociology of harm conventions through the ontology of critical realism serves to resituate the production of sociological knowledge with regard to normative concern, and re-theorise the link between them. Following this reconstruction it becomes possible, through Critical Theory, to address the kind of theory that is needed in order to interrogate the problem of harm in International Studies.