Within the discipline of International Relations, a critical research agenda has developed that questions the limits of global knowledge and expertise. Here, the reflexive sociology of Pierre Bourdieu has been mobilised to conceptualise social factors delimiting knowledge production. However, this critical enterprise has been challenged by scholars working within the pragmatist and post-humanist traditions. These scholars have critiqued the alleged structuralist rigidity and anthropocentric bias of critical sociology. They instead call for a flat ontology that emphasises the fragility of social formations and places non-human actants—such as technologies—on par with human agents. In riposte to these criticisms, this chapter defends the analytical utility of critical sociology, arguing that a Bourdieusian framework enables an investigation of tacit knowledge and struggles for legitimacy. While new technologies have altered epistemic practices, the post-humanist turn is also rejected on the basis that humanist advocacy is still fundamentally an inter-human phenomenon revolving around social authority, persuasion and a logic of dependence. Yet, rather than seeing NGO advocates as inhabiting a homogenous metafield with a monolithic logic, this chapter also calls for a plural conception of advocates’ lifeworlds that recognises their co-immersion in multiple social spaces.