The label ‘human security’ (HS) has attracted much attention since the 1994 Human Development Report, but there are numerous conflicting definitions and agendas and widespread scepticism. The Ogata-Sen Commission report Human Security Now has proposed a unified yet flexible definition and agenda. This paper specifies the Human Security Now concept as the intersection of: a concern with reasoned freedoms; a focus on basic needs; and a concern for stability as well as levels in key human development dimensions. Second, it specifies other elements of this human security discourse: a normative focus on individuals’ lives and insistence on basic rights for all; and an explanatory agenda that stresses the nexus between freedom from want and indignity and freedom from fear. Third, it clarifies where the HS discourse repeats the Basic Human Needs conception and where it adds, and shows the consistency of the human security, human needs and human rights languages. Fourth, it specifies the types of intellectual ‘boundary work’ which the concept and discourse attempt: mobilizing attention and concern, connecting explanatory and normative agendas, and linking diverse intellectual and policy communities. Lastly, it assesses HS as a boundary concept, including the particular label chosen, and diagnoses the threats as well as opportunities implicit in security language.