The notion that scholars and practitioners of career development ought to direct their attention towards agency is axiomatic. However, there is little explicit discussion in the literature of how we might conceptualise agency to orient our work towards issues of social justice. Career work draws on a range of disciplinary theoretical perspectives and so, in conceptualising agency, we must address the foundational issue of adequately theorising the relationship between individual and social aspects of career. In this paper we present a critique of Archer's work on agency as a basis for introducing Stetsenko's post-Vygotskian "Transformative Activist Stance" as an ontology of persons and social life in which agency is meaningfully individual, ineluctably social, and continually directed towards bringing a desired world into being.